CN100379680C - Polymer-based composites comprising carbon nanotubes as a filler, method for producing said composites, and associated uses - Google Patents

Abstract

The invention relates to a method for producing carbon nanotubes in a dispersed state, said method being characterised in that it comprises a stage whereby polymerisation is carried out from at least one so-called monomer of interest, in the presence of a catalytic system, said catalytic system comprising a co-catalyst/catalyst catalytic couple that is supported by a catalyst carrier, said catalyst carrier corresponding to said carbon nanotubes. The invention also relates to composite materials obtained by said method, and to a catalytic system for implementing said method. The invention further relates to the use of the inventive method and products in the field of polymers, especially that of nanotechnologies.

Description

Comprise carbon nanotube as the matrix material based on polymkeric substance of filler, the method and the associated uses thereof of the described matrix material of production

Invention field

The present invention relates to the material field, more particularly, be defined as the field of compound material of micron matrix material and nano composite material below the present invention relates to.

The present invention be more particularly directed to a kind of method that obtains matrix material, this matrix material comprises the matrix of at least a polymkeric substance, is scattered here and there in the matrix to serve as the carbon nanotube of filler.The invention still further relates to the described matrix material of such acquisition, and their purposes in field of nanometer technology.

Prior art

Polymer materials was developed in 20 beginnings of the century, had now occupied the position that becomes more and more important in our daily life.

Just because of this reason, the pressure from industry requires the specialized day by day of purposes at present, therefore must provide more and more effective material to satisfy this demand.

Under the situation of polymer materials, this demand means provides solution to overcome the inherent weakness of these materials, and particularly they lack physical strength and their inflammableness relatively.

Therefore, proposed these polymer materialss and other component that is known as " filler " are combined, be known as the material of " matrix material that contains polymeric matrix " with production, the performance of this material is compared independent polymeric matrix and is enhanced: have higher rigidity, better resistivity against fire etc.

These fillers can be the fibril types, as glass, carbon or Kevlar fiber.These fillers can also be granule types, as carbon black, silicon oxide, aluminum oxide, lime carbonate, clay or granulated glass sphere.

As an example, " polymerization-filling technique (Polymerization-Filling Technique) " or " PFT " (people such as Alexandre M. gives chapter and verse, Macromol.Rapid.Comm. (2000), the 21st volume, the 13rd phase, the 931-936 page or leaf), make alkene polymerization on filler in the presence of promotor/catalyzer right, thereby preparation is based on the matrix material of copolyolefine.The catalyzer of test is a metallocenes, more properly, is tert-butyl amido dimethyl (tetramethyl--n5-cyclopentadienyl) silane dimethyl titanium (CGC); With promotor be methylaluminoxane (MAO).Test multiple filler, comprised kaolin and graphite.With regard to forming (inorganic, organic or metal), form and surface property (acid or alkalescence), these fillers have very totally different character, but, they all generally have the specific surface area that adapts with the relative a small amount of of catalyst system therefor, thereby make catalyzer be deposited on the surface of these fillers full and uniformly, obtain good polymerization effect thus.

According to the particulate size, the matrix material that utilizes polymeric matrix and granular filler to form can be divided into filler size and be approximately the nano composite material of 1 nanometer to tens nanometer more than or equal to one of 1 micron micron matrix material and three-dimensional dimension of filler.

At present nano composite material suitable research and development have been carried out.Reason is that they have significant performance for low relatively filler content: they make the mechanical property of polymeric matrix such as rigidity significantly improve, and develop a kind of fire retardancy that they are highly profitable that makes.In addition, opposite with fibril type filler, they are all strengthening polymeric matrix on the direction in space ^[1,2]

More particularly, proposed to comprise carbon nanotube and be used for multiple use as the nano composite material of granular filler ^[3-6]On the thing border, carbon nanotube is one of allotropy form of carbon, and its one or more blades that can be regarded as graphite are rolled into cylindrical, and terminal sealed.Especially, these carbon nanotubes are characterised in that the favorable mechanical performance, because their tensile strength is higher 40 times than carbon fiber, and their good electrical properties, they are used for making semi-conductor or metallic conductor so that proposed to depend on the structure of nanotube.

But, in practice, use nanotube to make nano composite material and temporarily can not satisfy the industry expection as the filler in the polymeric matrix.More specifically, the useful performance that has proved carbon nanotube can not transferred on the nano composite material.

Explain that these data can be based on the trend naturally of carbon nanotube, they are tending towards flocking together and form highly stable bundle or " bundle ".

Therefore those skilled in the art faces the rendezvous problem of nanotube, and this problem has limited the application of nanotube in nano composite material, and unfortunately, those skilled in the art is still waiting for that a kind of effective solution overcomes this problem at present.

It may be noted that the application of carbon nanotube in catalyst system itself is known, this can be proved by document US-A1-2003/0 119 920 and " Japanese patent abstract (Patent Abstractsof Japan) " the 2000th volume the 6th phase (20.09.2000).

In these documents the former described a kind of catalyst system, and it comprises the carrier that covered by one deck carbon nanotube and catalyst composition that can catalyzed chemical reaction.This catalyst system can be used in a lot of chemical reactions, especially for polyreaction.But the carbon nanotube that described document provides does not form an integral part of this catalytic carrier itself.

The latter in these documents has described and a kind of carbon nanotube has been deposited on method on the catalysis molybdenum on the inorganic carrier.Therefore in the described document, catalyst system comprises (i) carbon nanotube, (ii) molybdenum catalyst and (iii) can liken the inorganic carrier of promotor to, and wherein, carbon nanotube has constituted by the product of the reaction of described catalyst.

Goal of the invention

The present invention aims to provide a kind of solution that does not have above-mentioned prior art defective.

Especially, the present invention aims to provide a kind of method that obtains carbon nanotube, and this carbon nanotube is the form that is dispersed in the polymeric matrix, and it can be used as the filler of matrix material, particularly nano composite material based on polymkeric substance.

The present invention also aims to provide matrix material, nano composite material particularly, this matrix material comprises the matrix of at least a polymkeric substance, at least carbon nanotube serves as filler, wherein, the dispersion of carbon nanotube makes matrix material, particularly nano composite material, can be advantageously in conjunction with the industrial favourable physics and the chemical property of described polymkeric substance and described carbon nanotube.

Another object of the present invention provides and a kind of carbon nanotube is dispersed in method in the polymeric matrix, compares with the method that prior art proposes, and the enforcement of this method is simple relatively and rationally.

The invention summary

The present invention relates to a kind of method that obtains the carbon nanotube of discrete form, it is characterized in that this method comprises one and be called as at least a monomer step of polymerization in the presence of catalyst system of " interested monomer ", wherein said catalyst system comprises that the catalysis that loads on the promotor/catalyzer on the catalytic carrier is right, and described catalytic carrier is corresponding to described carbon nanotube.

More specifically, the present invention relates to a kind of method that obtains matrix material, this matrix material comprises at least a polymeric matrix, wherein serve as filler even carbon nanotube be dispersed in this polymeric matrix, described method is characterised in that: start from described carbon nanotube and monomer, described carbon nanotube as catalytic carrier with promotor/catalyzer to equably in conjunction with in its surface, thereby formation catalyst system, make described catalyst system have activity for polyreaction, and described monomeric polymerization utilizes described active catalytic system to carry out on carbon nano tube surface, make this polymerization carry out the sufficiently long time, with when described monomer polymerization carries out, around described carbon nanotube, little by little obtain this polymeric matrix, then, reclaim the matrix material that forms.

" dispersion of nanotube in polymeric matrix " is meant the dispersion of nanotube in described matrix, thereby the surface in contact between two carbon nanotubes is long-pending less than 20% of described nanotube total surface area, preferably less than 10%, preferably less than 5%, less than 2%, be more preferably less than described nanotube total surface area 1%.

Term " evenly " is meant that the distribution of carbon nanotube in polymeric matrix is uniformly at least on micron level, preferably even on Nano grade.

Preferably, the method according to this invention may further comprise the steps:

The suspensoid of-preparation carbon nanotube in inert solvent;

-by adding described promotor described carbon nanotube is carried out pre-treatment, to obtain the suspensoid of pretreated carbon nanotube, wherein promotor is adsorbed on the surface of carbon nanotube;

-by in the suspensoid of described pretreated nanotube, adding catalyzer and making the suspensoid preparation feedback mixture of monomer flow circulation cause pretreated carbon nanotube like this, thereby in described reaction mixture, make described monomer on the surface of described nanotube, carry out polymerization, form the matrix material that comprises described interested polymkeric substance and described carbon nanotube thus, wherein said carbon nanotube is by described interested polymer overmold;

-when the polymerization in the reaction mixture has reached required about 0.1%～about 99.9% percent polymerization, stop polyreaction, reclaim the described matrix material of synthetic thus.

Preferably, interested monomer is that alkene and interested polymkeric substance are polyolefine.

Described polyolefine can be hydrophobic polyolefine especially.

Preferably, described interested monomer is selected from ethene, propylene, and the multipolymer of they and alpha-olefin, conjugation α-diolefine, vinylbenzene, cyclenes, norbornylene, norbornadiene and cyclopentadiene, and composition thereof.

The example of alpha-olefin comprises 1-hexene and 1-octene.

Preferably, interested polymkeric substance be selected from polyolefine based on ethene, based on the polyolefine of propylene, and composition thereof.

Advantageously, interested polymkeric substance is a polyethylene.

Advantageously, in the method for the invention, select promotor/catalyzer to and experiment parameter, make catalyzer to be fixed on the surface of carbon nanotube, thereby form catalyst system by promotor.

Therefore, preferably, thereby selecting catalyst makes it can the interested monomeric polymerization of catalysis, and described catalyzer is selected from two (imino-) pyridines of metallocenes, sterically hindered amido aryl sequestrant, sterically hindered oxo aryl sequestrant, iron (II and III) and cobalt (II) and based on nickel (II) and the Brookhart complex compound of palladium (II) and their mixture.

Usually, these all catalyzer have the total fact, that is, they all are the soluble complexes that possesses active IV family's chemical element (Ti, Zr, Hf) in polymerization.

Should be noted that metallocenes can bridging or non-bridging.

Also advantageously, promotor is the methylaluminoxane of methylaluminoxane or chemical modification or their mixture.

" methylaluminoxane of chemical modification " is meant that wherein about 1/3rd alkyl takes the isobutyl-form, and all the other described alkyl are taked the methylaluminoxane of methyl form.

In a particularly advantageous mode, the catalysis of this promotor/catalyzer is to being methylaluminoxane/Cp ^* ₂ZrCl ₂Right.

Preferably, the catalytic amount in the inventive method is about 10 ^-6～about 10 ^-5The moles per gram carbon nanotube.

Preferably, the amount of the promotor in the reaction mixture is about 10 ^-3～about 10 ^-2The moles per gram carbon nanotube.

Advantageously, the temperature of reaction mixture is 25 ℃～140 ℃.

Preferably, according to the present invention, pre-treatment was carried out under 25 ℃～200 ℃ 1 minute～2 hours.

Advantageously, polyreaction is carried out under the monomer pressure of about 1～about 3 crust, preferably carries out under the monomer pressure of 1.1～2.7 crust.

Preferably, for the preparation feedback mixture,, catalyzer is added in the suspensoid of pretreated carbon nanotube making before monomer flow circulates in described suspensoid.

Alternatively,, catalyzer is added in the suspensoid of pretreated carbon nanotube, and monomer flow is circulated in described suspensoid for the preparation feedback mixture.

Preferably, carbon nanotube is selected from Single Walled Carbon Nanotube, double-walled carbon nano-tube and multi-walled carbon nano-tubes and their mixture.

Preferably, carbon nanotube is rough and/or the purified carbon nanotube.

In the method for the invention, carbon nanotube can be functionalized carbon nanotube.

Preferably, when percent polymerization makes matrix material contain to have an appointment the polymkeric substance of 50%～about 99.9% carbon nanotube and about 50%～0.1%, stop polyreaction.

Under the situation of back, the method according to this invention preferably includes an additional step, in this step, in case reclaim, this matrix material is used as master batch with the nano composite material of preparation based on the polymkeric substance that is referred to as addition polymer, but the interested polymkeric substance mixing of described addition polymer and matrix material and compatible.

Alternatively, when percent polymerization enough obtains the fully matrix material of amount, this matrix material is corresponding to nano composite material and comprise the matrix of described interested polymkeric substance, and wherein carbon nanotube is evenly dispersed on Nano grade in the matrix, stops polyreaction.

More specifically, when the nano composite material that forms contains when having an appointment 0.1%～50% carbon nanotube and about polymkeric substance of 99.9%～about 50%, preferably stop polyreaction.

The invention still further relates to a kind of catalyst system that is used to carry out aforesaid method, it is made up of carbon nanotube, promotor and catalyzer, it is right that described catalyzer and described promotor form catalysis, and wherein said catalyzer and described promotor are attached on the surface of described carbon nanotube.

The invention still further relates to a kind of composition that is used to implement this method and comprises described catalyst system, this catalyzer is selected from two (imino-) pyridines of metallocenes, sterically hindered amido aryl sequestrant, sterically hindered oxo aryl sequestrant, iron (II and III) and cobalt (II) and is the methylaluminoxane of methylaluminoxane or chemical modification or their mixture based on the Brookhart complex compound of nickel (II) and palladium (II) and their mixture and this promotor.

The invention still further relates to a kind of matrix material that obtains by aforesaid method.

This matrix material comprises about 0.1%～99.9% carbon nanotube and about 99.9%～0.1% polymkeric substance.

According to first preferred embodiment of the present invention, this matrix material is corresponding to nano composite material and comprise at least a matrix of at least a interested polymkeric substance, and wherein carbon nanotube is evenly dispersed on Nano grade in this matrix with the form of filler.

Preferably, this matrix material comprises about carbon nanotube of 0.1%～about 50% and about polymkeric substance of 99.9%～about 50%.

Preferably, in matrix material according to the present invention, carbon nanotube is aggregated thing and covers or coat.

The invention still further relates to a kind of matrix of at least a addition polymer and matrix material of above-mentioned matrix material of comprising.

Another object of the present invention is aforesaid method and/or catalyst system and/or composition and/or the purposes of matrix material in field of nanometer technology is used.

The invention still further relates to a kind of interested monomeric polymerization process that is called as, it is characterized in that this polymerization process has adopted the method according to this invention, make this polyreaction carry out the sufficiently long time, so that the ratio of carbon nanotube is less than 0.1%, the ratio of polymkeric substance is greater than 99.9%.

The invention still further relates to the polymkeric substance that a kind of method thus obtains.

Definition

With reference to the paragraph of front, understand the implication of term among the present invention " nano composite material ", " micron matrix material ", " gathering/disaggregation ", " dispersion ", " polymeric matrix " and " filler ".

It should be noted that polymeric matrix comprises at least a polymkeric substance.

Term " matrix material " relate to micron matrix material and nano composite material the two.

In order specifically to understand the implication of term among the present invention " matrix material " or " mixture ", can be with reference to document " material and matrix material (Mat é riaux etcomposites) " (the Tec ﹠amp of Berthelot J.M.; Doc publishes, the third edition, Paris, 1999, page 3).

The implication of term among the present invention " catalyzer " is identical in the implication that chemical field adopts with those skilled in the art.A kind of compound represented in this term, when it is used for reaction medium with low-down concentration, can improve the speed of polyreaction by the interaction of itself and reagent, but change chemically can't take place for it when reaction finishes.

The implication of term among the present invention " promotor " is identical in the implication that chemical field adopts with those skilled in the art.A kind of compound represented in this term, and it can act synergistically to improve the speed of polyreaction with catalyzer.

Term " poisonous substance " is meant the compound that suppresses polyreaction.

Whether form by one, two or more above-mentioned blade respectively according to carbon nanotube, carbon nanotube is called " single wall ", " double-walled " or " many walls ".This nomenclature is known for those skilled in the art.

Summary of drawings

The schematically illustrated the method according to this invention of Fig. 1 a is applied to the principle under the polyethylene situation.

Fig. 1 b illustrates the activation of the method according to this invention zirconocene catalyst on nanotube surface.

Fig. 2 is illustrated in and exists and do not exist under the situation of rough multi-walled carbon nano-tubes (MWNT), and the polymerization kinetics curve ratio of vinyl polymerization.

Fig. 3 represents the method according to this invention, and the kinetic curve that carries out vinyl polymerization with the catalyst system that contains or do not contain rough multi-walled carbon nano-tubes compares.

Fig. 4 a is corresponding to the SEM electron photomicrograph of rough MWNT carbon nanotube sample.

Fig. 4 b is corresponding to the enlarged view of getting on the sample of Fig. 4 a, thereby can see bundle or aggregate.

Fig. 4 c is corresponding to the SEM electron photomicrograph of sample, and this sample comprises rough MWNT nanotube and 10wt% polyethylene, and its method according to this invention is by helping the preparation of catalysis system in conjunction with MAO.

Fig. 4 d is corresponding to the enlarged view of getting on the sample of Fig. 4 c.

Fig. 4 e is corresponding to the SEM electron photomicrograph of sample, and this sample comprises rough MWNT nanotube and 42wt% polyethylene, and its method according to this invention is by preparing in conjunction with the MAO promotor.

Should be during Fig. 4 f in the enlarged view of on the sample of Fig. 4 e, getting.

Fig. 5 a is the Photomicrograph of the transmission electron microscope (TEM) of Fig. 4 a and the captured sample of Fig. 4 b, corresponding to independent rough MWNT carbon nanotube.

Fig. 5 b is the Photomicrograph of the transmission electron microscope (TEM) of Fig. 4 e and the captured sample of Fig. 4 f, corresponding to rough MWNT nanotube and 42wt% polyethylene.

Fig. 5 c is the Photomicrograph of the transmission electron microscope (TEM) of sample, and this sample is corresponding to rough MWNT nanotube and 74wt% polyethylene, and this sample the method according to this invention is by preparing in conjunction with the MAO promotor.

Fig. 6 shows based on the aerial TGA differential thermogram of the different mixtures of HDPE matrix relatively.Sample Dabo 40a correspondence only contains the mixture of HDPE matrix, the simple mixtures of corresponding HDPE matrix of sample Dabo 40b and rough MWNT carbon nanotube (2wt%), the mixture of corresponding HDPE matrix of sample Dabo 40c and master batch, this master batch contains the rough MWNT carbon nanotube (2wt%) that the method according to this invention obtains.

Fig. 7 is the photo that the sample Dabo 40b burning back of earlier paragraphs definition is taken.

Fig. 8 is the photo that the front same section makes a decision and takes after adopted sample Dabo 40c burns.

Fig. 9 a is the TEM Photomicrograph of same sample Dabo 40b, and Fig. 9 b is corresponding to the regional enlarged drawing that contains the MWNT carbon nano-tube bundle.

Figure 10 a is the TEM Photomicrograph of same sample Dabo 40c, and Figure 10 b is corresponding to the enlarged view that isolated M WNT carbon nanotube is shown.

Figure 11 has compared the simple aggregation of ethene and the polymerization kinetics of the vinyl polymerization that the method according to this invention is carried out on Single Walled Carbon Nanotube (SWNT).

The stretch test result of three kinds of sample types has been compared in Figure 12～16: independent high density polyethylene(HDPE); The matrix material that obtains by simple mixing high density polyethylene(HDPE) and 1% multi-walled carbon nano-tubes (MWNT); The matrix material that obtains by high density polyethylene(HDPE) and master batch prepared in accordance with the present invention.

More specifically, following parameter has been compared in Figure 12～16:

--Figure 12: rupture stress

--Figure 13: elongation at break

--Figure 14: yang type modulus

--Figure 15: yield point stress

--Figure 16: elongation at yield point

Detailed Description Of The Invention

Novelty of the present invention is the design implemented: according to being known as " polymerization-filling technique " (it is abbreviated as " PFT ")^[8]Technology, via the polymerization procedure on the filler of having processed, the preparation polyethylene/CNT nano composite material.

In this polymerization procedure, the catalyst that becomes known for the interested monomer polymerization of catalysis is incorporated on the surface of filler (that is, in this case, advantageously taking the pretreated CNT of suspended substance form). Then, on the surface of same filler, directly cause the polymerization that is concerned monomer.

According to the present invention, during this step, the pressure that polymerisation produces in carbon nano tube surface is in a kind of fully mode beyond expectation, so that the common bundle disaggregation relevant with the formation of the nano composite material of carbon nanotubes. Then, in nano composite material, obtained form the dispersion in polymeric matrix of CNT with filler, and this dispersion is uniform at Nano grade.

It should be noted that the preliminary treatment of CNT is co-catalyst is attached on the surface of CNT, the selection of co-catalyst is based on that it can cooperate to have catalytic activity in the polymerization process of monomer with catalyst. In other words, this means co-catalyst and catalyst are selected so that they are formed for the catalysis pair of monomer polymerization together, and this means that CNT can be regarded as catalytic carrier, its with described catalysis to limiting catalyst system and catalyzing.

Should be appreciated that according to the present invention the combination of catalyst on carbon nano tube surface undertaken by co-catalyst, thus catalyst and co-catalyst by chemisorbed to the surface of nanotube.

By ethene and the specific embodiment of preparation based on the nano composite material of polyethylene matrix, can illustrate the present invention.

But, emphasize such as above-mentioned institute, the invention still further relates to other polymer and other nano composite material that those skilled in the art can determine easily on this specification basis.

This is equally applicable to the character of catalyst and co-catalyst.

But, should be noted that a necessary condition of implementing according to the inventive method is that formed interested polymer is insoluble to polymerisation medium (reactant mixture), thereby it can just in the site of its polymerization,, precipitate on the surface of CNT that is.

Fig. 1 a has summed up the principle that method of the present invention is applied to the polyethylene situation. As shown in the drawing, direct polymerization on the nanotube surface of ethene in suspended substance causes along with poly synthetic, and CNT is little by little coated or covers by polyethylene. The effect that coats forces CNT separated from one another, produces thus the disaggregation of the bundle of nanotube.

As embodiment, the co-catalyst of employing is MAO, is abbreviated as MAO, with its preliminary treatment CNT. This co-catalyst uses with the solution form.

This co-catalyst can pass through the interaction of lewis acid-bases type, interacts with the CNT wall that is rich in pi-electron.

Add subsequently the catalyst that adopts as embodiment, that is, and two (1,2,3,4,5-pentamethyl cyclopentadienyl group) zirconium dichloride (IV), or Cp^* ₂ZrCl ₂ It also uses with the solution form.

It should be noted that shown in Fig. 1 b, when the filler that contact MAO processes, Cp^* ₂ZrCl ₂Be created in the activated cationic substance of tool in the vinyl polymerization, and be positioned at the negative counter ion on the filler after the processing.

By the combination of this active material, ethene is polymerization on filling surface. Because polyethylene is insoluble to solvent for use, so it passes through the precipitation Direct precipitation on the surface of filler (that is, CNT).

Agents useful for same:

Used filler is multi-walled carbon nano-tubes (MWNT). Adopt two types nanotube, namely, still containing the 30wt% catalytic impurities (mainly is the aluminium oxide of about 30wt%, the cobalt of 0.3wt%, iron with 0.3wt%) rough MWNT, with the refining MWNT that contains trace catalytic impurities (aluminium oxide of 0.2wt%, the iron of 0.3wt%, and the cobalt of 0.3wt%). These nanotubes are by Facult é s Universitaires Notre Dame de la Paix, and the J.B.Nagy of Namur professor's department provides.

Solvent for use is normal heptane (AG is from Acros company). It has been the upper drying of molecular sieve (also being provided by Acros company) of 0.4 nanometer in porosity.

The toluene preparation of some soln using drying. For this reason, the toluene (AG) that is provided by Labscan company in calcium hydride boiling thus make it dry, and then fresh distillation.

The co-catalyst of selecting is the MAO (MMAO) of Atofina company. 3M～the 0.2M of MAO in toluene is molten synthetic for this.

Here use two (1,2,3,4,5-pentamethyl cyclopentadienyl group) zirconium dichloride (IV) (Cp^* ₂ZrCl ₂) (from Aldrich company) as catalyst. It is dissolved in the dry toluene, forms the solution of 1～10mM.

Adopt as ethene that supply, gas form (99.998%) (from Air Liquide company).

With methyl alcohol (technical grade) (from Brenntag company) precipitation and recovery polymer or composite.

With co-catalyst preliminary treatment CNT:

(0.25g～1g) packs into (according to subsequent applications) in two mouthfuls of round-bottomed flasks of 250ml or 500ml, and flask is equipped with magnetic stirring bar and is equipped with glass three-way joint (good with the rubber septum plug) with rough nanotube.

Flask is connected in the vacuum trap that immerses liquid nitrogen, the water that is adsorbed with recovery, and adjusted, that is, under vacuum, use Bunsen flame dry. Then make nanotube dried overnight under vacuum, 100～150 ℃ and electromagnetic agitation. Flask places under the nitrogen that omits pressure-fired.

Then the 100ml normal heptane is added in the flask. To dry, a certain amount of MAO (0.001～0.01 moles per gram MWNT) discharges trimethyl aluminium wherein in advance by vaporising under vacuum. The condensation in the vacuum trap that immerses liquid nitrogen of the trimethyl aluminium of evaporation stores to be used for analysis. Must remove trimethyl aluminium (TMA), because verified, TMA will be the effective competition person of MAO aspect absorption as a kind of lewis acid of excellence^[7]。

Solid MAO is dissolved in the toluene again, and under nitrogen, by capillary it is transferred on the suspended substance of MWNT in heptane.

Utilize oil bath to make system's constant temperature remain on 20～60 ℃, electromagnetic agitation 10 minutes～2 hours.

Vacuum Concentration MAO in the presence of MWNT is until drying, with the solvent condenses of removing in the round-bottomed flask that immerses liquid nitrogen (filler processing section).

Then oil bath temperature is risen to high temperature (100～200 ℃), kept 30 minutes～3 hours, make simultaneously flask be in vacuum (10^-1Holder) under, so that MAO is attached on the CNT. And then flask is placed under the nitrogen of malleation slightly.

Then wash three times to remove the MAO that is not attached on the filler. The dry toluene that for this reason adds 80ml in the nanotube is 60 ℃ of lower stirrings 5 minutes. Make the filling settlement after MAO processes, do not stir. Then flow down with the capillary of regulating at nitrogen and take out supernatant liquor. Merge subsequently three parts of solution and this filler processing section (normal heptane).

Under vacuum, capture a small amount of residual toluene that exists in the flask, it be concentrated in the flask that immerses in the liquid nitrogen, thus after time it is added in this filler processing section.

After this was processed, therefore flask contained pretreated nanotube.

In the presence of with the pretreated CNT of co-catalyst, ethylene homo:

Should be noted that catalyst is attached on the pretreated nanotube carries out in inert media, it remains under the nitrogen of pressure-fired slightly, thereby has avoided the existence of proton impurity and oxygen in the reaction medium.

In order to carry out ethylene homo, in the flask of the nanotube that contains the MAO processing, add the 100ml normal heptane.

Then under nitrogen atmosphere, mixture is transferred in the preregulated round bottom reactor that magnetic stirring bar is housed.

Under nitrogen atmosphere, add 1 * 10^-5～1×10 ^-6Mole Cp^* ₂ZrCl ₂/ gram nanotube. Then with the round bottom reactor in oil bath between 25 ℃～100 ℃ (polymerization temperature) constant temperature kept 5～60 minutes.

Then used the ethylene stream blowing medium 30 seconds. Polymerization is 1 hour under the ethylene pressure of 1.1～2.7 bar. The composite that synthesizes by making subsequently is from being reclaimed by precipitation the methyl alcohol of 12M hcl acidifying.

The description of the present invention's first preferred embodiment

1. agents useful for same:

Used filler is multi-walled carbon nano-tubes (MWNT).Adopt two types nanotube, promptly, still containing the 30wt% catalytic impurities (mainly is the aluminum oxide of about 30wt%, the cobalt of 0.3wt%, iron with 0.3wt%) rough MWNT, with the refining MWNT that contains trace catalytic impurities (aluminum oxide of 0.2wt%, the iron of 0.3wt% and the cobalt of 0.3wt%).These nanotubes are by Facult é s Universitaires Notre Dame de la Paix, and the J.B.Nagy of Namur professor's department provides.

Solvent for use is normal heptane (AG is from Acros company).The last drying of molecular sieve (also being provided by Acros company) of 0.4 nanometer has been provided in porosity for it.

Some soln using exsiccant toluene preparation.For this reason, the toluene (AG) that boiling is provided by Labscan company on hydrolith thus make it dry, and then fresh distillation.

The promotor of selecting is the methylaluminoxane (MAO) of Atofina company.The solution of the 1.45M of MAO in toluene is used to synthesize.

Here use two (1,2,3,4,5-pentamethyl-cyclopentadienyl) zirconium dichloride (IV) (Cp ^* ₂ZrCl ₂) (from Aldrich company) as catalyzer.It is dissolved in the exsiccant toluene, forms the solution of about 5mM.

Adopt as ethene that supplied, gas form (99.998%) (from AirLiquide company).

With methyl alcohol (technical grade) (from Brenntag company) precipitation and recovery polymkeric substance or matrix material.

2. with promotor pre-treatment carbon nanotube:

Rough nanotube (according to circumstances adopting 0.25g or 1g) is packed into (according to subsequent applications) in two mouthfuls of round-bottomed flasks of 250ml or 500ml, and this flask is equipped with magnetic stirring bar and is equipped with glass Y-junction (good with the rubber septum plug).

Flask is connected to the water that is adsorbed with recovery in the vacuum trap that immerses liquid nitrogen, and adjusted, that is, under vacuum, use the Bunsen flame drying.Make nanotube dried overnight under vacuum, 100 ℃ and induction stirring then.This flask places under the nitrogen of slight positive pressure.

Then the 100ml normal heptane is added in the flask.To dry, a certain amount of MAO, its aluminum concentration are 1.45M (32ml/ gram MWNT or 46mmol/ gram MWNT), discharge trimethyl aluminium wherein in advance by vaporising under vacuum.The trimethyl aluminium of evaporation is condensate in the vacuum trap that immerses liquid nitrogen, stores to be used for analysis.It is necessary removing trimethyl aluminium (TMA), because verified, TMA will be the effective competition person of MAO aspect absorption as a kind of Lewis acid of excellence ^[7]

Solid MAO is dissolved in the toluene once more, and under nitrogen, it is transferred on the suspensoid of MWNT in heptane by kapillary.

Utilize oil bath to make system's constant temperature remain on 40 ℃, induction stirring 1 hour.

In the presence of MWNT, vacuum concentration MAO is until drying, with the solvent condenses of removing in the round-bottomed flask that immerses liquid nitrogen (filler treating part).

Then oil bath temperature is risen to high temperature (150 ℃), kept one and a half hours, flask is in vacuum (10 simultaneously ^-1Holder) under, so that MAO is attached on the carbon nanotube.Once more flask is placed under the nitrogen of slight positive pressure subsequently.

Wash three times then to remove the MAO that is not attached on the filler.The dry toluene that for this reason adds 80ml in nanotube stirred 5 minutes down at 60 ℃.Make the filling settlement after MAO handles, do not stir.Under nitrogen gas stream, take out supernatant liquid then with the kapillary of regulating.Merge three parts of solution and this filler treating part (normal heptane) subsequently.

Under vacuum, capture the small portion of residual toluene that exists in the flask, and be concentrated in the flask that immerses liquid nitrogen, thus after time with its adding filler treating part in.

After this was handled, therefore flask contained pretreated nanotube.

3. in the presence of the pretreated carbon nanotube of promotor, ethylene homo:

Should be noted that the combination of catalyzer on pretreated carbon nanotube carry out in inert media, it remains under the nitrogen of slight positive pressure, thereby has avoided existing in the reaction medium proton impurity and oxygen.

In order to carry out ethylene homo, in the flask of the nanotube (0.25g) that contains the MAO processing, add the 100ml normal heptane.

Then mixture is transferred in the preregulated round bottom reactor that magnetic stirring bar is housed.

2.2ml the Cp of 5mM ^* ₂ZrCl ₂Solution (is 11.5 μ mol for the 0.25g nanotube) [lacuna].Then with the round bottom reactor in oil bath under 50 ℃ (polymerization temperature) constant temperature kept 15 minutes.

Used the ethylene stream blowing medium then 30 seconds.Polymerization is 1 hour under the ethylene pressure of 2.7 crust.Subsequently, the synthetic matrix material is reclaimed from precipitating the methyl alcohol of 12M hcl acidifying by making.

4. result

4.1 independent carbon nanotube does not have relevant catalytic activity:

It should be noted that for test objective, polymerization time shortened to 30 minutes from 60 minutes.

Verified, rough carbon nanotube does not show catalytic activity in vinyl polymerization.

Carry out polyreaction under various conditions at various samples, what obtain the results are shown in the table 1 for this reason.

As shown in table 1, when in the presence of not having the MAO promotor, carrying out polymerization (seeing sample 24b and 28a), do not obtain polymkeric substance, and have a spot of polyethylene of next acquisition (seeing sample Dabo24a) at MAO.

Empirical tests, the product that obtains in the presence of MAO is polyethylene (not shown herein data) really.

4.2 carbon nanotube for catalysis to there not being poison effect:

Table 2 and test-results shown in Figure 2 can prove: rough many walls nanotube does not constitute for MAO/Cp ^* ₂ZrCl ₂The poisonous substance that catalysis is right.

Particularly, if exist and do not exist without pretreated rough multi-walled carbon nano-tubes condition under polymerization, relatively two kinds of catalytic activitys under the situation identical (seeing Table 2) are observed in ethene consumption in time, and in fact, the overlapping (see figure 2) of ethene consumption curve under two kinds of situations.

Should be noted that the amount of the polyethylene in kg (pE) that catalytic activity is defined as every mole of Zr and per hour produces.

4.3 carbon nanotube is used as catalytic carrier in vinyl polymerization:

According to the present invention, verifiedly it is shocking that very carbon nanotube can be used as MAO/Cp in vinyl polymerization ^* ₂ZrCl ₂Right catalytic carrier.

This result is particularly amazing, because a large amount of πDian Zis can make them become effective Lewis base on the known carbon nanotube of those skilled in the art, can compete with olefinic type monomers in theory such as ethene, therefore, on the contrary, those skilled in the art expects that polyreaction is with inactivation or even be suppressed.

For this reason,, carry out aggregation test, the results are shown among table 3 and Fig. 3 of these tests existing and not existing under the condition of pretreated rough multi-walled carbon nano-tubes.

As shown in table 3, the catalytic activity of observing sample Dabo21 (corresponding to the polymerization of carrying out) in the presence of pretreated nanotube has increased by 50% than the activity that sample Dabo23 (not having described nanotube) obtains.This means, the catalytic activity of catalyst system in vinyl polymerization that forms is higher than the activity of the right system of the catalysis that only contains this catalyst/co-catalyst by the catalysis of carbon nanotube loaded catalyst/co-catalyst.

Polymerization kinetics as shown in Figure 3 relatively confirmed these results.

4.4PE/ the hotlist of rough MWNT matrix material is levied:

By between polymerization period, taking out different fractions, synthesized and had the matrix material that poly content increases, and utilize these different composite materials, variation of melting point and the degree of crystallinity measured between polymerization period by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) change.

Corresponding results is shown in Table 4.Shown in these results, along with the poly ratio of synthetic increases, fusing point increases gradually, and degree of crystallinity also increases, and reaches threshold value (66%) up to it.

These results prove and have formed the matrix material that the polyethylene ratio increases.And, the increase of the polyethylene ratio that contains along with them, the thermal characteristics of these mixtures also increases thereupon.

4.5 the morphology of rough PE/MWNT matrix material characterizes:

Fig. 4 a～4f illustrates the SEM Photomicrograph that is obtained by various rough PE/MWNT matrix materials, and these matrix materials contain the changeable weight content of polyethylene with respect to carbon nanotube, and its scope is 0%～42%.

According to phenomenon well-known to those skilled in the art, as shown in Figs. 4a and 4b, in the sample of carbon nanotubes only, can observe these carbon nanotubes and have the trend that natural and spontaneous gathering becomes the shape of bundle, piece or bundle.These bundles are pointed out by arrow.

With this sample point as a comparison, can find that along with the weight content of synthetic polyethylene in matrix material increases these bundles have the cumulative trend that is tending towards disaggregation (Fig. 4 c～4f).

Should be noted that the additional morphological analysis that is undertaken by scanning electron microscope (SEM) (not shown) has confirmed this trend herein, that is, is the polyethylene of 50wt%～75wt% for content, is tending towards " bundle " of destroying carbon nanometer tube.

In order to make the coating visualize of nanotube, (TEM) analyzes various samples with transmission electron microscope, and these samples contain the polyethylene of 0wt%, 42wt%, 74wt%.The photo that is obtained by these various samples is shown in Fig. 5 a～5c.

Go out as shown,, observe " bundle " of carbon nanotube and (see Fig. 5 a) for corresponding to the sample that does not contain poly rough MWNT nanotube.These Shu Hanyou scopes are the nanotube of the different diameter of about 10～about 40 nanometers.Their length is several microns.Should be noted that at the appreciable object in photo center and can liken the granules of catalyst (containing cobalt and iron) that is used to produce nanotube to.

On the other hand, for corresponding to the sample that contains the poly rough nanotube of 42wt% (Fig. 5 b), on sample edge, observe the part coating (see the arrow of Fig. 5 b) of polyethylene to carbon nanotube.

For relatively, shown in Fig. 5 c, for containing poly more at high proportion sample (containing the poly rough nanotube of 74wt%), the rough nanotube ratio that is coated (covering) by polyethylene increases.Among this figure, point out the nanotube that coated with black arrow, and the with dashed lines arrow points out to be rich in very much poly zone.Particularly as seen this be coated on the sample edge.

4.6 the refining influence of carbon nanotube to gained PE/MWNT matrix material:

Be similar to the measurement (data not shown goes out) of the catalytic activity of above-mentioned rough carbon nanotube with the purified carbon nanotube.

This research makes can prove that aspect catalytic activity, carrier is effective equally by the catalyst system that rough carbon nanotube constitutes by catalyst system and carrier that refined carbon nanotubes constitutes.

With with above-mentioned research wherein many walls nanotube be the similar mode of matrix material of rough nanotube, study wherein carbon nanotube by the matrix material of many walls of purified PE/ nanotube (MWNT).

The result who obtains (not shown herein) proves, the thermal characteristics of the PE/ multi-wall carbon nano-tube composite material that these obtain with refined carbon nanotubes and morphological feature and the material property that obtains with rough carbon nanotube have comparability.

In addition, these results make and can illustrate that comparing carbon nanotube is rough situation, and when carbon nanotube was refining, " bundle " of destroying carbon nanometer tube needed less polyethylene.Can make explanations by the following fact: the refining of carbon nanotube reduced them at intrafascicular structure.Particularly, refining making may be removed the catalysis residue that is positioned at bundle " bottom ", and this residue has partly been guaranteed their bonding.

4.7 as master batch, prepare matrix material with the PE/MWNT nanometer tube composite materials:

For the vinyl polymerization that can determine on the rough multi-walled carbon nano-tubes that MAO handles, to provide according to the present invention, the preparation melted blend.

In order to make these mixtures possess comparability, need matrix identical.Use HDPE matrix (from Dow company), this HDPE matrix in mass melt flow index under 2.16kg, 190 ℃ is 1.1g/10 minute for this reason.

These mixtures that preparation adopts this matrix to form are that compression moulding in mould then is so that the forming materials that obtains by blend in sealing inner room (Brabender).

More specifically, in the blending machine of enclosed chamber, fusion also mixes this polymeric matrix and filler (polyethylene coated carbon nanotube).In case this material fusion and thorough mixing move into the surface with it and are covered with in the suitable stainless steel mould of polytetrafluoroethylene film.Use the whole thing (to make it to have fully the shape of mould) of hydraulic press hot pressing then, cold pressing subsequently (so that material setting).Obtain the thick composite panel of 3mm thus.

Here the blending machine of usefulness is the interior formula blending machine (about 70g polymkeric substance) of Brabender, and press is that Agila PE20 hot/cold biliquid is pressed press.190 ℃ (screw speed: 45rpm) down blend 2 minutes, only make HDPE fusion and mixing, and then blend 10 minutes, make it to mix with filler.Pressing process is as follows: following 3 minutes low pressure, 190 ℃; 150 the crust and 190 ℃ following 3 minutes; Do not heat at last 150 the crust under 5 minutes.

Therefore, prepare three kinds of mixtures by blend in inner room.They are independent HDPE matrixes (sample Dabo 40a), contain 2wt% without the HDPE matrix (sample Dabo 40b) of the pretreated rough MWNT of MAO with the matrix (sample Dabo 40c) that contains rough MWNT that 2wt% handles through MAO and coated, use with the master batch form by the ethene in-situ polymerization.In fact, should " master batch " by obtaining in conjunction with several samples, this sample is that the method according to this invention is obtained by ethene polymerization on the rough multi-walled carbon nano-tubes that MAO handles, and takes out from vinyl polymerization between polymerization period.In this " master batch ", the polyethylene that the method according to this invention original position produces is about 70wt% with respect to the ratio of the amount of rough MWNT.

4.7.1 machinery and viscoelastic property:

Every kind of mixture is carried out tension test to determine mechanical property, get the mean value of minimum 5 samples.Draw speed is 50mm/ minute.In addition, (MFI) determine viscoelastic property with " melt flow index meter ".

What obtain the results are summarized in the table 5.

The parameter of summing up in this table is known for those skilled in the art.As prompting, the sample mechanical parameter in this table is determined as follows:

--Young's modulus (E) is the feature of the initial strain intensity (rigidity) of material;

--" yield point stress " and " yield sign strain " stress value and stretch value (σ when corresponding respectively to fluid threshold _s, ε _s);

--the melt viscosity of " MFI " exosyndrome material.

The result of table 5 shows, adds nanotube and the rigidity of HDPE matrix is not produced remarkably influenced (seeing Table 5 the 3rd hurdles " Young's modulus ").

On the other hand, the reduction (seeing Table 5 the 2nd hurdles) of breaking strain is followed in the adding of these nanotubes.

But, adopt " master batch " to make and can keep limiting performance, for example high relatively rupture stress and breaking strain, they are features (sample Dabo40b and Dabo 40c are compared) that the ductility of material is kept.

About viscoelastic property (last hurdle of table 5, " MFI "), the adding of MWNT carbon nanotube has greatly reduced MFI, that is, the adding of carbon nanotube is tending towards increasing the melt viscosity of material.

But through comparing, the pre-treatment of the vinyl polymerization of the method according to this invention on the nanotube that MAO handles causes the less reduction of the MFI factor, that is, the increase of melt viscosity is less than simple mixtures (Dabo 40b).This can be by following facts explain: the method according to this invention makes carbon nanotube disperse better and has therefore produced the MFI factor that is relatively higher than simple mixtures.The better dispersion of MWNT and the destruction of consequent " bundle " are likely the reason that causes melt viscosity to increase, and it has increased the flowability that matrix is got to know by standard.

In a word, according to the present invention, by carrying out the pre-treatment of the carbon nanotube of vinyl polymerization on the nanotube of handling at MAO, the feasible mechanical property that can improve resulting matrix material, thereby allow between the rigidity of material and ductility, to keep balance preferably, keep being suitable for the viscosity of material intended application simultaneously.

4.7.2 thermal characteristics:

For various mixtures, carry out heat analysis with differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and compare.The data that obtain are summarised among table 6 and Fig. 6.

These digital proof matrix materials have high slightly fusing point (the 1st hurdle of table 6, " m.p. ") than independent matrix.

The following fact has constituted absorbing data, that is, the method according to this invention contains the matrix material (sample Dabo40c) of the nanotube that coats by the MAO pre-treatment and by polyethylene, the gain aspect thermostability even be better than simple mixtures.

Also find, very advantageously be, in the presence of rough MWNT (Dabo 40b and Dabo 40c item), HDPE matrix degradation temperature (about 50 ℃) of (in the air) in oxidizing atmosphere is significantly higher than degradation temperature (sample Dabo 40a) (" the airborne T of independent HDPE matrix _Deg. " hurdle).The clear this point that proved of the differential thermogram of Fig. 6.

In other words, although the feasible stability that can improve the HDPE matrix of the simple mixing of carbon nanotube and HDPE matrix, but can know from the present invention, in the presence of the carbon nanotube that the method according to this invention is handled, even the content of this carbon nanotube is little of 2wt%, still makes and can even further improve this thermostability.

4.7.3 burning behavior:

Material behavior during the test of carrying out is burning sample and observes burning: may form can be with propagation of flame to the drop of lighting of surrounding medium, material deformation, intensive volatilization etc.

When lighting with the independent corresponding sample of HDPE matrix (Dabo 40a), its burning produces the drop of lighting.Flame is very rapid along the propagation of this sample, causes the burning of whole initial sample.

In comparison, the burning of the sample corresponding with the matrix material that contains the HDPE matrix no longer forms any drop of lighting: this matrix material is the rough MWNT (Dabo 40b) that obtains by simple mixing and contain 2wt%.Propagation of flame is slower than the situation of independent HDPE matrix.After the burning, as shown in Figure 7, although this sample is out of shape, this sample has still been kept its original dimension on the whole.This observations is typical " charing " phenomenon, and it is derived from the carbonization owing to the organic matrix that existence caused of Nano filling, and this causes forming the shell (" charcoal ") of carbonization.

In principle, do not compare, can not further improve the burning behavior of HDPE matrix, prove (sample Dabo 40c) as Fig. 8 according to the processing of carbon nanotube of the present invention with the carbon nanotube of not handling (sample Dabo 40b) according to present method.

Even so, the matrix material that contains the rough MWNT that 2wt% the method according to this invention handles that forms with the HDPE matrix shows the behavior that is better than independent matrix.Contain at matrix material under the situation of untreated carbon nanotube, do not observe not existing fully to light and form shell (" charcoal ") (see figure 8) under the mobile situation.

In a word, the carbon nanotube that the method according to this invention is handled is incorporated into the matrix material that will make formation in the HDPE matrix and does not form the drop of lighting when burning, and compares independent HDPE matrix, and it has slower velocity of propagation.But, in principle, between matrix material that obtains by simple and mechanical mixing HDPE and rough MWNT nanotube and the matrix material that obtains by the MWNT that mixes HDPE and handle according to the inventive method, the burning behavior of the two does not show any significant difference.

4.7.4 morphology characterizes:

In order to make the state visualize of carbon nanotube disaggregation, two kinds of matrix material Dabo40b and Dabo 40c are carried out the morphology sign by transmission electron microscope (TEM), respectively, they obtain by mixing HDPE and rough MWNT on the one hand, on the other hand by mixing HDPE and obtaining according to the MWNT that the inventive method is handled.Corresponding photo is shown in respectively among Fig. 9 a, 9b and 10a, the 10b.

As can be seen, the melted blend of rough MWNT and HDPE (matrix material Dabo40b) does not enough make nanotube " bundle " disaggregation effectively.Particularly, in Fig. 9 of this matrix material a and 9b, can see " bundle " (seeing arrow and enlarged view) of nanotube.

By comparing, with transmission electron microscope (TEM) the matrix material Dabo 40c that contains the carbon nanotube of handling according to method of the present invention is carried out morphological analysis, demonstrate the better dispersion (seeing Figure 10 a and 10b) that in matrix, has carbon nanotube, because no longer see " bundle " of nanotube.On the contrary, seen that separated toward each other carbon nanotube (sees Figure 10 a).The scatter table of nanotube reveals in entire sample even relatively.

In a word, the observation of carrying out with transmission electron microscope (TEM) has proved the superiority of the inventive method, it passes through enveloped carbon nanometer tube, thereby make natural " bundle " disaggregation that is tending towards forming, and, therefore make these nanotubes by melt blended and be distributed to relatively equably in the polyethylene matrix.Therefore can consider veritably: in the HDPE matrix, add master batch and caused forming the nano composite material that meets this term stricti jurise.

On the contrary, the melt blended of untreated carbon nanotube and HDPE do not cause producing nano composite material, but causes having produced the micron matrix material, in this micron matrix material, finds that " bundle " of nanotube is present in the polyethylene.

The description of the present invention's second preferred embodiment

The method according to this invention, also prepared contain double-walled carbon nano-tube (DWNTs) as filler based on poly nano composite material.Experiment condition is as follows:

In decompression, under 105 ℃, 0.8g DWNT dried overnight.In nanotube, add the MAO solution (46.5ml solution, wherein aluminum concentration is 0.8M) that discharges TMA.Remove desolvate after, be attached on the carbon nanotube in order to promote MAO, 150 ℃ of following heated mixt 90 minutes.To remove unconjugated MAO, the amount (24.6mmol combination) of bonded MAO is determined in titration with the exsiccant toluene wash.The Cp that in the DWNT that MAO handles, adds 200ml normal heptane and 18.4 μ mol ^* ₂ZrCl ₂1.1 the crust ethylene pressures and 50 ℃ under carry out polymerization., take out the various sample fractions of matrix material (nano composite material), and make it from acidifying methyl alcohol, to be precipitated out between synthesis phase at polyethylene, be used for analyzing.Before the analysis, dry under 150 ℃, vacuum have a nano composite material 90 minutes that polymerized ethylene content increases.

Then, in sealed cabin, carry out dsc analysis, prove that fusing point and degree of crystallinity all increase (data not shown goes out) when the polymerized ethylene content in the nano composite material increases.

Also nano composite material is analyzed, confirmed the result that obtains by DSC, and confirm, obtained the nano composite material (data not shown goes out) that polymerized ethylene content increases really when overtime sample time with TGA.

The description of the 3rd preferred embodiment

In the 3rd preferred embodiment, the method according to this invention, prepared contain Single Walled Carbon Nanotube (SWNT) as filler based on poly nano composite material.Experiment condition is identical with the condition that first embodiment is used for MWNT type nanotube.

The result of the matrix material that the method according to this invention obtains, the result of the polymkeric substance that obtains with simple aggregation, the two relatively be shown in Table 7 by ethene.

As shown in table 7, the simple aggregation when not having nanotube is compared, and making as the inventive method of filler with SWNT type carbon nanotube to increase the catalytic activity of polyreaction.

In addition, the polymerization kinetics comparative studies that polymerization in the presence of SWNT type nanotube is carried out to simple aggregation and above-mentioned the method according to this invention proves, their kinetics has comparability in first 20 minutes, but the speed of simple aggregation begins to weaken afterwards, and continues to increase (seeing Figure 11) according to rate of polymerization of the present invention.

Also the sample that simple aggregation is obtained (Dabo B 013a) and carried out hot analysis according to the sample that obtains based on the polymerization of SWNT nanotube of the present invention (matrix material Dabo B 012) the results are shown in the table 9.

Analyze as can be known from this, only the polymkeric substance that obtains by simple aggregation has the lower fusing point of matrix material that obtains than according to the present invention, but degree of crystallinity is higher.

To having carried out hot research based on poly nano composite material, this matrix material contains SWNT type carbon nanotube, obtains and have the polymerized ethylene content of increase according to the present invention; It the results are shown in the table 8, this result makes and can prove: the certain correspondence of the product that obtain the sample time of prolongation has the matrix material of the polymerized ethylene content of raising, and for the polymerized ethylene content of the raising that forms, can observe fusing point increase and degree of crystallinity increases.

The description of the 4th preferred embodiment

The method of describing in detail in the first embodiment according to the present invention prepares matrix material, but several places difference is arranged.Adopt the 1.23mmol MAO of minimum,, under this MAO amount, ethene polymerization on carbon nanotube is always arranged because experiment before is verified.In addition, saved the step of removing TMA and be heated to the step of 150 ℃ of after scouring carbon nanotubes.Handle the MWNT of 1g in addition with the normal heptane of MAO that contains 4.9mmol aluminium and 40ml.

For ethylene homo, adopt the normal heptane of 175ml and the Cp of 16.4 μ mol ^* ₂ZrCl ₂

For purpose, the matrix material that so obtains has been carried out thermogravimetric analysis as " master batch ".Analyze and show the composed as follows of this matrix material:

--39.7wt% polyethylene (obtaining down helium, 20 ℃/minute) by TGA

--5.8wt% aluminum oxide (obtaining down air, 20 ℃/minute) by TGA

--the MWNT (determining) of 54.5wt% by the amount that deducts polyethylene and aluminum oxide.

Empirical tests (by differential scanning calorimetry (DSC)), really synthesized polyethylene (PE): the PE feature fusing point that records is 134.4 ℃ (second time that is determined at circulation DSC (10 ℃/minute) is by in (passage)), degree of crystallinity be 51% (by second time of circulation DSC by in melting heat calculate).

The master batch that obtains thus through extruding/inject be distributed to business type once more high-density matrix (HDPE) (from Dow company, MI ₂=1.1g/10 minute) in, new matrix material obtained.Experiment condition is as follows:

--service temperature: 190 ℃

--the sample introduction cycle: 4 minutes, 30rpm

--loop cycle: 6 minutes, 60rpm

--reclaim: 2 minutes, 60rpm

--injection compartment temperature: 190 ℃

--injection temperature (molding): 100 ℃ (each technological operation produces two tension test samples)

Preparation abreast only contains poly sample, or comprises that polyethylene and 1wt% multi-walled carbon nano-tubes (MWNT) are through the simple matrix material that obtains that directly mixes.

In addition, synthesized " master batch " based on MWNT, its composition is defined as the 39.7wt% polyethylene, 5.8wt% aluminum oxide, and 54.5wt%MWNT.

Then, make three types sample experience tension test, draw speed is 50mm/ minute, below the results are shown in.

Rupture stress and elongation at break

Shown in Figure 12 and 13, for according to the present invention by disperseing for the matrix material that master batch obtains the performance of composites that its limiting performance (rupture stress and elongation at break) is better than independent polyethylene and obtains by direct mixing once more.

Young's modulus

Figure 14 illustrates, and the Young's modulus value of the various materials that obtain during the injection all is positioned at identical numerical range, and these values all are positioned at the relative measurement error of every kind of material.

Yield point stress and elongation at yield point

Yield point stress (Figure 15) has been carried out identical observation with the value of elongation at yield point (Figure 16).

In a word, the result who obtains proves, especially with independent polymer phase ratio, also can with compare with the matrix material that described filler obtains by the described polymkeric substance of direct mixing, adopt based on polymeric matrix, contain carbon nanotube that with good grounds the present invention obtains and can increase limiting performance as filler and as the matrix material of master batch.In other words, the method according to this invention can obtain wherein the limiting performance of carbon nanotube is transferred to nano composite material on the matrix material as desired.

Extra test should prove: carbon nanotube also relates to other physicals to the performance that matrix material shifts.

Table

Table 1

Sample	Cp * 2ZrCl 2 (μmol)	MAO (mmol)	Used rough MWNT quality (g)	The total mass that obtains (g)	The maximum PE weight (g) that obtains	m.p. (℃)	The degree of crystallinity of PE (wt%)
								24a	0	11.5	0.1	0.240	0.140	128.3	18
24b	11.5	0	0.1	0.100	0	/	/
								28a	0	0	0.1	0.100	0	/	/
28b	0	11.5	0	0.038	0.038	131.0	25

The result who obtains at the various vinyl polymerization duration of test that start from rough MWNT (ethene 2.7 crust, 50 ℃, 30 minutes)

Table 2

Sample	Al/Zr (mol/mol)	m Rough MWNT (g)	m Matrix material (g)	m PE (g)	Active (kg/mol Zr·h)	The rough MWNT (wt%) that obtains
							16	1000	0.25	10.21	9.96	866	2.5
11	1000	0	/	9.90	861	0

Table 3

Sample	Al/Zr (mol/mol)	m Rough MWNT (g)	m Matrix material (g)	m PE (g)	Active (kg/mol Zr·h)	The rough MWNT (wt%) that obtains
							21 1	450	0.25	14.37	14.12	1228	2.5
23 1	450	0	/	9.79	851	/

Explain: ¹11.5 μ molCp ^* ₂ZrCl ₂V _HeptaneAlways: 100ml;

1 hour, 50 ℃, ethene 2.7 crust (0.25g MWNT)

Table 4

Sample time a	Sample volume (ml)	The weight that obtains (g)	m.p. (℃) C	WcPE (independent) b，c(％)	PE content d (wt％)
						t 1(Dabo 30a)	38	0.388	130.9	45	42
t 2(Dabo 30b)	40	0.637	132.1	60	57.5
						t 3(Dabo 30c)	39	0.769	132.8	68	71.2
t 4(Dabo 30d)	50	1.419	132.9	66	73.7
						t 5(Dabo 30e)	39	1.577	133.1	66	78.3

Explain: P _Ethene=1.1 crust; T=50 ℃; 1g MWNT/200ml normal heptane;

46μmolZr/g MWNT；Al/Zr＝240

^aThe timed interval between each sampling: 1～2 minute

^bDeduct the degree of crystallinity of the PE matrix being calculated by behind the filler content of TGA mensuration

^cDSC for the second time by during the value that obtains

^dThe value that TGA obtains under helium

Table 5

Mixture	Rupture stress (MPa)	Breaking strain (MPa)	Yang type modulus (MPa)	Yield point stress (MPa)	Yield sign strain (%)	MFI (g/10 minute)
							Dabo 40a	31±1.6	744±41	386±44	24.4±0.3	10±0.5	1.01
Dabo 40b	15.3±1.1	98±20	419±46	25.2±2.2	11.2±2.5	0.53
							Dabo 40c	21.7±2.4	468±55	414±30	25.5±0.5	10±1	0.70

Table 6

Mixture	m.p. (℃)	The PE (%) that Wc is independent	Airborne T deg. (℃) a	T among the He deg.(℃) a
					Dabo 40a	134.5	62.6	421	493
Dabo 40b	134.9	62.4	473	498
					Dabo 40c	135.6	61.7	485	498

^aDerivative maximum value by the differential thermogram (see figure 6) is determined

Table 7

Sample	SWNT	The amount of the MAO of " combination "	[Al]/[Zr]	The PE quality that obtains	Active (kg/mol 2r·h)
						Dabo B 013a	Not	9mmol	783	15.64g	1360
Dabo B 012	Be	9mmol	783	21.28g	1850

Table 8

Sample time a	Al 2O 3 b wt％	PE c wt％	H 2O c wt％	SWNT d wt％	m.p. (℃) e	Wc PE (independent) f
							t 1(Dabo B 015a)	25.5	30.2	16.6	27.7	130.0	26
t 2(Dabo B 015b)	20.6	48.4	13.7	17.3	131.5	43
							t 3(Dabo B 015c)	15.3	63.4	10.2	11.1	133.5	51
t 4(Dabo B 015d)	5.1	82.8	4.1	7.2	133.8	57

^aThe timed interval between each sampling: about 1～2 minute

^bTGA measures (20 ℃/minute, under 900 ℃) in air

^cTGA measures (20 ℃/minute) in helium

^dAmount according to PE, aluminum oxide and water is determined

^eTo 150 ℃ of following exsiccant samples, pass through period detecting in the second time of circulation DSC (10 ℃/minute)

^fTo 150 ℃ of following exsiccant samples, the PE that obtains based on TGA and the degree of crystallinity calculated

Table 9

Sample	SWNT	m.p. (℃) a	Wc(％) b	Alumina content c (wt％)	NT content d (wt％)
						Dabo B 013a	Not	132.9	71	Do not measure	Measure
Dabo B 012	Be	135.3	59	1.2	2.2

^aPass through period detecting in the second time of circulation DSC (10 ℃/minute);

^bCalculate by the melting heat during passing through the second time of circulation DSC;

^cTGA measures (20 ℃/minute) in air;

^dTGA measures (20 ℃/minute) in helium, therefrom deduct the aerial remnants of TGA.

Reference:

[1]A.B.Morgan，J.W.Gilman，T.Kashiwagi，C.L.Jackson；Flammability of polymer-clay nanocomposites(March 12-15 2000)，the National Institute of standardsand Technology.

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Claims (34)

1. obtain the method for matrix material, this matrix material comprises at least a polymeric matrix, in the presence of the carbon nanotube in being dispersed in described polymeric matrix, make monomer polymerization form polymkeric substance and obtain this polymeric matrix, described monomer is called " interested monomer " and described polymkeric substance is called " interested polymkeric substance ", and described method is characterised in that:

-described carbon nanotube is as catalytic carrier, with right in conjunction with promotor/catalyzer equably in its surface, forms catalyst system;

-make described catalyst system have activity for polyreaction;

-described monomeric polymerization utilizes described active catalytic system to carry out on the surface of carbon nanotube, makes this polymerization carry out the sufficiently long time, with when described monomer polymerization carries out, obtains described polymeric matrix around described carbon nanotube.

2. method according to claim 1 is characterized in that may further comprise the steps:

The suspensoid of-preparation carbon nanotube in inert solvent;

-by adding described promotor described carbon nanotube is carried out pre-treatment, to obtain the suspensoid of pretreated carbon nanotube, wherein promotor is adsorbed on the surface of carbon nanotube;

-by in the suspensoid of described pretreated nanotube, adding catalyzer and making the suspensoid preparation feedback mixture of monomer flow circulation cause pretreated carbon nanotube like this, thereby in described reaction mixture, make described monomer on the surface of described nanotube, carry out polymerization, form matrix material thus, wherein said carbon nanotube is by described interested polymer overmold;

-when the polymerization in the reaction mixture has reached 0.1%～99.9% percent polymerization, stop polyreaction.

3. method according to claim 1 and 2 is characterized in that described monomer is that alkene and described interested polymkeric substance are polyolefine.

4. method according to claim 1 and 2, it is characterized in that described interested monomer is selected from ethene, propylene, the multipolymer of they and alpha-olefin, conjugation α-diolefine, vinylbenzene, cyclenes, norbornylene, norbornadiene and cyclopentadiene, and composition thereof.

5. method according to claim 3 is characterized in that described interested polymkeric substance is a polyethylene.

6. according to the described method of aforementioned each claim, it is characterized in that in order to form this catalyst system, select promotor/catalyzer to and experiment parameter, make catalyzer to be fixed on the surface of carbon nanotube by promotor.

7. according to the described method of aforementioned each claim, it is characterized in that this catalyzer can this interested monomeric polymerization of catalysis and this catalyzer is selected from two (imino-) pyridines of metallocenes, sterically hindered amido aryl sequestrant, sterically hindered oxo aryl sequestrant, iron (II and III) and cobalt (II) and based on nickel (II) and the Brookhart complex compound of palladium (II) and their mixture.

8. according to the described method of aforementioned each claim, it is characterized in that this promotor is the methylaluminoxane of methylaluminoxane or chemical modification or their mixture.

9. according to the described method of aforementioned each claim, the catalysis that it is characterized in that this promotor/catalyzer is to being methylaluminoxane/Cp ^* ₂ZrCl ₂Right.

10. according to the described method of aforementioned each claim, the amount that it is characterized in that this catalyzer is 10 ^-6～10 ^-5The moles per gram carbon nanotube.

11. according to the described method of aforementioned each claim, the amount that it is characterized in that this promotor in this reaction mixture is 10 ^-3～10 ^-2The moles per gram carbon nanotube.

12. according to the described method of aforementioned each claim, the temperature that it is characterized in that this reaction mixture is 25 ℃～140 ℃.

13., it is characterized in that this pre-treatment carried out 1 minute～2 hours under 25 ℃～200 ℃ according to the described method of aforementioned each claim.

14., it is characterized in that carrying out under this monomer pressure that is aggregated in 1～3 crust according to the described method of aforementioned each claim.

15., it is characterized in that carrying out under this monomer pressure that is aggregated in 1.1～2.7 crust according to the described method of aforementioned each claim.

16. according to the described method of aforementioned each claim, it is characterized in that in order to prepare this reaction mixture,, catalyzer joined in the suspensoid of this pretreated carbon nanotube making before this monomer flow circulates in described suspensoid.

17., it is characterized in that catalyzer being joined in the suspensoid of this pretreated carbon nanotube, and monomer flow circulated in described suspensoid in order to prepare this reaction mixture according to the method for aforementioned claim 1-16 described in each.

18., it is characterized in that this carbon nanotube is selected from Single Walled Carbon Nanotube, double-walled carbon nano-tube and multi-walled carbon nano-tubes and/or their mixture according to the described method of aforementioned each claim.

19., it is characterized in that this carbon nanotube is rough and/or the purified carbon nanotube according to the described method of aforementioned each claim.

20., it is characterized in that this carbon nanotube is functionalized carbon nanotube according to the described method of aforementioned each claim.

21., it is characterized in that when percent polymerization makes that this matrix material contains the polymkeric substance of 50%～99.9% carbon nanotube and 50%～0.1%, stopping this polyreaction according to the described method of aforementioned each claim.

22. according to the described method of aforementioned each claim, it is characterized in that when the nano composite material that forms contain 0.1%～50% be dispersed in carbon nanotube in this polymeric matrix with Nano grade, during with 99.9%～50% polymkeric substance, stop this polyreaction.

23. according to the described method of aforementioned each claim, it is characterized in that comprising additional step, wherein this matrix material is as master batch, be used for preparing nano composite material based on the polymkeric substance that is known as " addition polymer ", but the interested polymkeric substance mixing of described addition polymer and this matrix material and compatible.

24. be used to implement catalyst system according to the described method of aforementioned each claim, it is made up of carbon nanotube, promotor and catalyzer, it is right that described catalyzer and described promotor form catalysis, and wherein said catalyzer and described promotor are attached on the surface of described carbon nanotube.

25. be used to implement composition according to the described method of aforementioned each claim, it comprises catalyst system according to claim 24, and this catalyzer is selected from two (imino-) pyridines of metallocenes, sterically hindered amido aryl sequestrant, sterically hindered oxo aryl sequestrant, iron (II and III) and cobalt (II), based on nickel (II) and the Brookhart complex compound of palladium (II) and their mixture; With this promotor be the methylaluminoxane of methylaluminoxane or chemical modification or their mixture.

26. the matrix material that obtains according to the described method of aforementioned each claim.

27. according to the matrix material that claim 1～26 method described in each obtains, it comprises 0.1%～99.9% carbon nanotube and 99.9%～0.1% polymkeric substance.

28. according to the matrix material that the described method of aforementioned each claim obtains, it is corresponding to the nano composite material of at least a matrix that contains at least a polymkeric substance, wherein carbon nanotube disperses equably with Nano grade.

29. matrix material according to claim 28, it comprises 0.1%～50% carbon nanotube and 99.9%～50% polymkeric substance.

30. according to each described matrix material of claim 26～29, wherein this carbon nanotube is aggregated the thing coating.

31. matrix material, it comprises the matrix of at least a addition polymer and according to each described matrix material of claim 26～30.

32. according to the purposes of each described method of claim 1～23 in making the carbon nanotube disaggregation.

33. the method for polymerization single polymerization monomer is characterized in that this method adopts according to each described method of claim 1～23, make this polyreaction carry out the sufficiently long time so that the content of carbon nanotube be less than 0.1% and polymer content greater than 99.9%.

34. polymkeric substance by method acquisition according to claim 33.

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