CN113527606B

CN113527606B - Antifogging polymethyl methacrylate and preparation method thereof

Info

Publication number: CN113527606B
Application number: CN202110740710.8A
Authority: CN
Inventors: 刘铭; 刘波; 王亚飞; 韩强
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2021-07-01
Filing date: 2021-07-01
Publication date: 2022-08-05
Anticipated expiration: 2041-07-01
Also published as: CN113527606A

Abstract

The invention relates to an antifogging polymethyl methacrylate (PMMA) and a preparation method thereof. According to the invention, an aniline graft chain segment is introduced into a polymethyl methacrylate side chain, and then the aniline monomer is terminated and the branched chain end group polymerization is carried out in an extruder, so that the branched chains have the conductive characteristic, and the photo-thermal effect is realized. The invention solves the problem of continuity between aniline grafted chains of polymethyl methacrylate, and enables the polymethyl methacrylate side chain to have the photoelectric conversion capability of a polyaniline-like structure, thereby further endowing the polymethyl methacrylate with certain photo-thermal effect. The polymethyl methacrylate has an antifogging function, and can be used for materials in the fields of glasses, goggles, automobiles, illumination and the like.

Description

Antifogging polymethyl methacrylate and preparation method thereof

Technical Field

The invention belongs to the field of polymer materials, and particularly relates to an antifogging polymethyl methacrylate and a preparation method thereof.

Background

Polymethyl methacrylate (PMMA) is a polymeric material that is primarily polymerized from methyl methacrylate. Has excellent optical performance, good weather resistance, scratch resistance, dimensional stability and the like. Therefore, the light-emitting diode is widely applied to the fields of automobiles, lighting, goggles, billboards, electronic appliances and the like.

In winter or during cold and hot alternation or swimming, a layer of water mist is often generated on the outer surface or inside of glasses, goggles, mobile phone lenses and the like, and the occurrence of some dangerous situations can be caused by sudden vision obstruction; the reason for the generation of the water fog is that indoor water vapor is condensed into fine water droplets when meeting the cold lens surface, so that the haze is instantly increased to obstruct the sight; the antifogging means commonly used at present comprises coating, spraying and the like, and the principle is that a hydrophilic film is coated on the surface of a lens to reduce the surface tension, so that formed water drops are horizontally paved into a water film to reduce the haze, and the conventional means are temporary or easily consumed.

The special molecular structure of the aniline graft chain segment has a photo-thermal conversion function through the special photoelectric effect, and the aniline graft structure has certain response to visible light, ultraviolet light and infrared light; however, aniline is polymerized on the polymethyl methacrylate side chains by grafting, and the grafted aniline side chains are not in contact with each other, so that the special photoelectric effect of the polyaniline structure cannot be realized, and the polyaniline structure does not have a photothermal conversion function.

In conclusion, the current antifogging polymethyl methacrylate mainly has the problems that the electric conduction among molecular chains cannot be realized only by means of copolymerization and grafting, and good photo-thermal effect cannot be realized; according to the invention, the end group of the side chain is endowed with unsaturated double bonds capable of being further polymerized by a special end capping agent, and the electric conduction among molecular chains is realized by high-temperature initiation of polymerization among the unsaturated double bonds at the end group, so that the antifogging polymethyl methacrylate has excellent photo-thermal effect.

Disclosure of Invention

The invention aims to provide polymethyl methacrylate with a special structure, and the special structure enables the material to perform photoelectric conversion so as to realize an anti-fog function.

The inventor finds that the special molecular structure of the aniline graft chain segment has a photo-thermal conversion function through the specific photoelectric effect, and the aniline graft structure has certain response to visible light, ultraviolet light and infrared light; however, aniline is polymerized on the polymethyl methacrylate side chains by grafting, and the grafted aniline side chains are not in contact with each other, so that the special photoelectric effect of the polyaniline structure cannot be realized, and the polyaniline structure does not have a photothermal conversion function. In the invention, an aniline-containing monomer is used as a graft polymerization end-capping agent, and unsaturated double bonds at a graft connection end group are further subjected to polymerization reaction, so that the distance between PMMA main chains is close enough, aniline graft chains can be entangled with each other, the electrical property of a polyaniline structure is realized, and the polymethyl methacrylate with an aniline graft side chain is endowed with a certain photo-thermal conversion effect. The anti-fog lens prepared from the polymethyl methacrylate can provide anti-fog lenses with different photo-thermal capabilities by controlling the molecular structure, can keep the temperature of the lenses at about 20-25 ℃ all the time under outdoor continuous illumination corresponding to the temperature in winter in different areas, keeps the temperature of the lenses at normal temperature, and greatly reduces small water drops generated on the lenses due to temperature difference, thereby achieving the anti-fog purpose.

In order to achieve the purpose, the invention adopts the following technical scheme:

an antifogging polymethyl methacrylate, the raw material of which comprises the following components:

I. 90-99 parts by mass, preferably 92-97 parts by mass of monomer methyl methacrylate;

II. Comonomer (b): 1-10 parts by mass, preferably 3-8 parts by mass of a monomer containing an aniline group;

III, pH regulator: 1 to 10 parts by mass, preferably 5 to 7 parts by mass of an acrylic group-containing monomer;

IV, grafting monomer: 1-30 parts by mass of aniline, preferably 5-20 parts by mass;

v, end capping agent: 1 to 5 parts by mass, preferably 2 to 4 parts by mass of 4-vinylaniline and/or N-allylaniline;

the structural formula of the comonomer of the component II is as follows:

wherein R is ₁ Is propenyl and R ₂ 、R ₃ 、R ₄ Is hydrogen, or R ₁ Is hydrogen and R ₂ 、R ₃ 、R ₄ One is vinyl and the other two are hydrogen; the component II comonomer is preferably 4-vinylaniline and/or N-allylaniline.

The monomer containing the aniline comprises unsaturated double bonds, and can be copolymerized with methyl methacrylate in a free radical polymerization manner; and meanwhile, the compound also contains an aniline group structure, and can also be used as a terminator or an end-capping agent for aniline oxidative polymerization.

In the present invention, the weight average molecular weight of the polymethyl methacrylate is 50,000-300,000, preferably 50,000-200,000, and more preferably 70,000-110,000.

In the invention, the cross-linking density characteristic value of the polymethyl methacrylate is 1.01-1.05.

In the present invention, the proportion of the aniline-containing monomer in the polymethyl methacrylate is 1 to 10wt%, preferably 3 to 8wt%, and more preferably 5 to 7wt%, based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

In the present invention, the polymerization ratio of aniline on the graft chain in the polymethyl methacrylate is 1 to 25wt%, preferably 5 to 15wt%, and more preferably 7 to 10wt%, based on 100wt% of methyl methacrylate participating in the main chain polymerization. When the copolymerization ratio of the aniline-containing monomer is too low and the polymerization ratio of the aniline side chain on the molecular chain is low, the terminal group polymerization of the aniline grafted chain is difficult to occur, the photothermal effect is low, and a good anti-fogging effect cannot be achieved; when the copolymerization ratio of the aniline-containing monomer is too high and the polymerization ratio of the aniline side chain on the molecular chain is higher, the optical and mechanical properties of PMMA are lost to a certain extent.

In the present invention, the ratio of the blocking agent in the polymethyl methacrylate is 1 to 5wt%, preferably 3 to 4wt%, based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

In the present invention, the component III acrylic group-containing monomer is one or more selected from acrylic acid, methacrylic acid, ethacrylic acid and butylacrylic acid, preferably acrylic acid and/or methacrylic acid, more preferably methacrylic acid. The main function of the acrylic monomer in the invention is to adjust the acidity of the system during the aniline side chain oxidation polymerization and improve the surface tension of the polymer.

Another object of the present invention is to provide a method for preparing the anti-fog type polymethyl methacrylate.

The polymerization process of the Polymethylmethacrylate (PMMA) of the present invention may be bulk polymerization, solution polymerization or suspension polymerization. From the viewpoint of product properties and process matching, the batch or continuous bulk polymerization method is preferred, and the continuous bulk polymerization method is more preferred.

The method for preparing the antifogging polymethyl methacrylate is characterized by comprising the following steps of:

s1: preparing materials: adding methyl methacrylate, a monomer containing an aniline group, an initiator 1, a chain transfer agent material and an optional additive into the batching tank A, and stirring to prepare a reaction liquid A; adding aniline, a monomer containing acrylic group and a material of an initiator 2 into the batching tank B, and stirring to prepare a reaction liquid B; adding ethylbenzene and a monomer containing aniline into the batching tank C, and stirring to prepare a reaction solution C; adding ethylbenzene and an initiator 3 into the material preparing tank D, and stirring to prepare a reaction liquid D;

s2: first-order reaction: preparing a main chain structure, and adding the reaction liquid A into a reaction kettle A for polymerization reaction to obtain slurry A; the sizing agent A mainly comprises methyl methacrylate/amino-containing monomer copolymer polymer D, and also comprises a large amount of methyl methacrylate and a very small amount of aniline monomer; polymer D has the following structural formula:

1)

2)

s3: and (3) secondary reaction: preparing a branched chain structure, adding the slurry A and the reaction liquid B into a reaction kettle B to carry out aniline graft polymerization reaction, and removing redundant methyl methacrylate to obtain slurry B; the slurry B mainly contains a polymer E obtained by grafting aniline with polymer D side chain aniline groups in S2, and also contains a small amount of aniline and acrylic monomers; graft polymer E has the following structural formula:

1)

2)

s4: end capping reaction: adding the slurry B and the reaction liquid C into a reactor C, and removing redundant aniline and ethylbenzene to obtain slurry C; the slurry C mainly comprises a polymer F obtained by terminating the graft chain end of the polymer E in the step (3) by a monomer containing an aniline, and also comprises ethylbenzene and a very small amount of a terminating agent; the branched end-capped polymer F has the following structural formula:

1)

2)

3)

4)

s5: and (3) extrusion reaction: and adding the slurry C and the reaction liquid D into an inlet of an extruder, and extruding and granulating to obtain the antifogging polymethyl methacrylate particles. The thermal polymerization between the backbones is as follows:

1)

2)

3)

4)

5)

6)

7)

8)

9)

10)

in the final product obtained above, the number of each repeating unit satisfies the following condition: the proportion of the aniline-containing monomer in the polymethyl methacrylate is 1-10wt%, preferably 3-8wt%, more preferably 5-7wt%, based on 100wt% of methyl methacrylate participating in main chain polymerization; the polymerization ratio of aniline on the graft chain in the polymethyl methacrylate is 1 to 25wt%, preferably 5 to 15wt%, more preferably 7 to 10wt%, based on 100wt% of methyl methacrylate participating in the main chain polymerization.

In the present invention, the initiator 1, the initiator 2 and the initiator 3 in S1 are one or more selected from dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxyacetate, dicumyl peroxide, 1-bis- (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, tert-butyl peroxy-3, 5, 5-trimethylhexanoate, tert-butyl peroxybenzoate, tert-butylperoxycumene, cumene hydroperoxide and tert-butyl hydroperoxide; wherein, the initiator 1 is tert-butyl peroxy-3, 5, 5-trimethylhexanoate, the initiator 2 is dicumyl peroxide, and the initiator 3 is tert-butyl hydroperoxide; preferably, the amount of the initiator 1 added to the reaction liquid A of S1 is 1X 10 based on 100 parts by mass of the monomer ^-2 -5×10 ^-2 Parts by mass, preferably 1X 10 ^-2 -3×10 ^-2 The monomer comprises 100 parts by mass of methyl methacrylate and a phenylamine-containing monomer, wherein the 100 parts by mass of the monomer comprises 100 parts by mass of methyl methacrylate and the phenylamine-containing monomer; reaction solution B the initiator 2 was added in an amount of 1X 10 based on 100 parts by mass of the monomers ^-3 -1×10 ^-2 Parts by mass, preferably 2X 10 ^-3 -5×10 ^-3 The monomer comprises 100 parts by mass of methyl methacrylate and a monomer containing phenylamino groups, wherein the 100 parts by mass of the monomer comprise 100 parts by mass of the methyl methacrylate and the monomer containing phenylamino groups; reaction solution D the initiator 3 was added in an amount of 1 to 2 parts by mass based on 100 parts by mass of the slurry C.

In the invention, the chain transfer agent of S1 is one or more of n-butylmercaptan, tert-butylmercaptan, n-octylmercaptan, isooctylthiol, n-dodecylmercaptan and tert-dodecylmercaptan, and preferably is n-octylmercaptan; preferably, the chain transfer agent is added in a proportion of 0.1 to 0.4 parts by mass, preferably 0.2 to 0.35 parts by mass, based on 100 parts by mass of the monomers of 100 parts by mass of methyl methacrylate and the phenylamino-containing monomer.

In the invention, the reaction kettle A in the S2 is a fully mixed flow high-pressure reaction kettle; controlling the temperature of the reaction kettle to be 120-150 ℃, preferably 130-140 ℃; the slurry A mainly comprises methyl methacrylate and a copolymer D containing an aniline-group-containing monomer, and also comprises methyl methacrylate and an aniline-group-containing monomer. The average residence time in the reaction vessel A is preferably from 1 to 4 hours, preferably from 2 to 3 hours. The "average residence time" means the ratio of the amount of liquid in the reaction vessel to the feed rate of the reaction liquid. The average residence time mainly affects the conversion. When the average residence time is too short, the conversion rate is difficult to satisfy the production requirements. When the average residence time is too long, the production economy is not achieved.

In the present invention, the conversion at the outlet of the reaction vessel A is preferably 50 to 70%, more preferably 55 to 65%. When the outlet conversion is too low, the production economy is not achieved. When the conversion rate of the outlet is too high, the viscosity of the materials in the reaction kettle is too high, which is not beneficial to mass and heat transfer. The conversion is regulated primarily by the initiator, the mean residence time and the reaction temperature.

In the invention, the S3 reaction kettle B is a fully mixed flow reaction kettle; the reaction temperature is controlled to be 150-180 ℃, and preferably 160-170 ℃; controlling the vacuum degree to 600-; the residual methyl methacrylate content in slurry B was <1000 ppm; the slurry B mainly contains a polymer E obtained by grafting aniline onto polymer D side chain aniline groups in S1, and comprises aniline and acrylic group-containing monomers. The average residence time in reactor B is preferably from 1 to 2 hours. The average residence time is too short, and the polymerization degree of the side chain grafted chain is too low to carry out the next end-capping polymerization; the average residence time is too long, and the degree of polymerization of the side chain branch chain is too high, so that the optical and mechanical properties of the polymer are reduced. The conversion rate at the outlet of the reaction kettle B is preferably 85-90%. The conversion was less than 85%, indicating insufficient degree of polymerization of the graft chain. The conversion rate is higher than 90%, and the melt viscosity is too high, so that the conveying efficiency is reduced, and the energy consumption is improved.

In the invention, the material in the S4 is added into a reactor C through a static mixer, and the reactor C is a fully mixed flow reaction kettle; controlling the reaction temperature to be 180 ℃ and 200 ℃; the vacuum degree is 400-; removing the redundant aniline and ethylbenzene until the aniline content is less than 5000ppm and the ethylbenzene content is less than 15%; the average retention time is 10-30 min; slurry C mainly contains polymer F in which the graft chain end of polymer E in S3 is further terminated by a monomer containing an aniline group, and also contains ethylbenzene and a terminating agent.

In the invention, the temperature of the extruder in S5 is 200 and 220 ℃, the vacuum degree is 15mbar, and the retention time is 10-15 min. The YI value of the product is higher due to too high temperature of the extruder or too long retention time; too low an extruder temperature or too short a residence time can result in incomplete polymerization of the terminal unsaturated double bonds.

When the heat-resistant polymethyl methacrylate is produced by the above-mentioned method, a mold release agent, an ultraviolet absorber, an antioxidant and a colorant aid may be added as required, and the type and amount of these additives are known to those skilled in the art.

The invention further aims to provide application of the antifogging polymethyl methacrylate.

The application of the antifogging polymethyl methacrylate is that the antifogging polymethyl methacrylate or the antifogging polymethyl methacrylate prepared by the method is used as a material in the fields of glasses, goggles, automobiles and illumination.

Compared with the prior art, the invention has the advantages that:

(1) the antifog polymethyl methacrylate prepared by the method can be heated to about 36 ℃ in 10min of illumination, and can be kept at a heating rate of 3-4 ℃/min, so that an excellent antifog effect is realized;

(2) besides successfully solving the photo-thermal effect capability of PMMA, the light transmittance can be kept to be more than 92 percent, and the performance requirements of application fields of most lenses and the like are met.

Drawings

FIG. 1 is a temperature-time curve of the polymethyl methacrylate optical sheets prepared in different examples under sufficient light.

Detailed Description

Embodiments of the present invention will be further illustrated with reference to the following examples. The invention is not limited to the embodiments listed but also comprises any other known variations within the scope of the invention as claimed.

The sources of the raw materials involved in the examples and comparative examples are shown in table 1:

table 1 raw material information referred to in the examples

The polymer-related structure and performance test method is as follows:

and (3) testing molecular weight:

the molecular weight was measured by liquid gel chromatography (GPC), mobile phase Tetrahydrofuran (THF), and the detector was a parallax refractometer. Monodisperse PMMA was used as standard. The instrument manufacturer: agilent; the instrument model is as follows: 1260 Infinity; and (4) testing standard: GB/T21863-2008.

Testing the structure of the polymer:

the polymer structure was tested using a 400MHZ nuclear magnetic resonance spectrometer (NMR). The instrument manufacturer: bruk; the instrument model is as follows: AVANCE III 400M NMR spectrometer.

Polymer crosslink density characteristic value test:

the PMMA particles were weighed out as W1 and then immersed in reagent grade toluene at 25. + -. 2 ℃ for 72hrs with stirring or with stirring. The swollen sample is then weighed to Wg, the sample is dried in an electric oven at 60 ℃ until the mass constant weight is unchanged, and then the final mass is weighed to Wd. The crosslink density is [ (Wg-Wd)/Wd ] K +1, where K is the ratio of the solvent (toluene density 0.865g/ml at 20 ℃) to the polymer (PMMA density 1.12g/ml at 20 ℃). And (4) testing standard: HG/T2875-1997.

Light transmittance and haze test:

the optical performance can be measured by a chromatic aberration analyzer to obtain total light transmittance, haze, YI value and the like. The instrument model is as follows: hunterlab VIS; and (4) testing standard: haze ISO 14782, light transmittance ISO 13148.

Melt index test:

MFR measurements were performed by melt index instrument, instrument manufacturer: GOTTFERT; the instrument model is as follows: MI 40; and (4) testing standard: ASTM D1238.

And (3) testing the conversion rate:

calculated from the ratio of the mass of the polymer at the outlet of the extruder per unit time to the feeding amount of the reaction liquid. And (3) arranging a sampling tube at an outlet of the reaction kettle A, and devolatilizing the sampling tube through a vacuum oven to measure the specific gravity of the solid residue and the sample so as to obtain the conversion rate.

Testing the change of the illumination temperature of the optical sheet:

the polymethyl methacrylate obtained in the preparation examples is subjected to injection molding by an injection molding machine to form optical sheets of 10 × 0.3cm, the injection molded optical sheets in different examples are simultaneously placed in a closed container with sufficient illumination, and the temperature of the injection molded optical sheets of the polymethyl methacrylate is recorded along with the illumination time by an infrared thermal imaging instrument. Referring to FIG. 1, the temperature variation curves of the PMMA optical sheets prepared by different examples under sufficient illumination are shown. Injection molding machine manufacturers: claus marfei; the model is as follows: KM 80PX Alie-SP 180; length-diameter ratio: 26; the screw diameter is 25 mm.

Example 1

S1: 5520g of methyl methacrylate, 480g of 4-vinylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 13.8g of n-octyl mercaptan are added into a preparation tank A and fully stirred for 10min to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; adding 240g of 4-vinylaniline into the material preparation tank C, diluting the mixture to 40% mass concentration by using 360g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

S2: first-order reaction: firstly, adding the reaction solution A into a fully mixed flow high-pressure reaction kettle A, controlling the reaction temperature to be 130 ℃ to carry out polymerization reaction, and keeping the average residence time for 3 hours to obtain a section of pre-polymerization slurry A with the conversion rate of 55%.

S3: and (3) secondary reaction: and (3) simultaneously adding the prepolymerization slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, controlling the reaction temperature to be 170 ℃, the vacuum degree to be 600mbar, and the average retention time to be 1h to obtain slurry B, wherein the conversion rate is 85%.

S4: end capping reaction: adding the slurry B and the reaction liquid C into the plug flow reactor C through a static mixer, controlling the reaction temperature to be 185 ℃, controlling the vacuum degree to be 400mbar, and controlling the average residence time to be 25min to obtain the slurry C.

S5: and (3) extrusion reaction: adding the slurry C and the reaction liquid D into a feed inlet of an extruder, controlling the temperature of the extruder to be 220 ℃, the vacuum degree to be 15mbar and the retention time to be 15min, carrying out the graft chain end group thermal polymerization reaction in the extruder and devolatilizing to obtain the polymethyl methacrylate particles. The results of the resin property test are shown in Table 2, and the resin light heat release test is shown in Table 3 and FIG. 1.

Example 2

S1: 5820g of methyl methacrylate, 180g of 4-vinylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of n-octyl mercaptan are added into a preparation tank A, and the mixture is fully stirred for 10min to prepare a reaction solution A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparing tank B, and fully stirring for 10min to prepare reaction liquid B; adding 240g of 4-vinylaniline into the material preparation tank C, diluting the mixture to 40% mass concentration by using 360g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

S2: first-order reaction: firstly, adding the reaction solution A into a fully mixed flow high-pressure reaction kettle A, controlling the reaction temperature to be 135 ℃ to carry out polymerization reaction, and keeping the average residence time for 3 hours to obtain a section of pre-polymerization slurry A with the conversion rate of 60%.

S3: and (3) secondary reaction: and (3) simultaneously adding the prepolymerization slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, and controlling the reaction temperature to be 165 ℃, the vacuum degree to be 600mbar and the average residence time to be 1.5h to obtain slurry B, wherein the conversion rate is 90%.

S4: end capping reaction: adding the slurry B and the reaction liquid C into an extrusion flow reactor C through a static mixer, controlling the reaction temperature to be 190 ℃, the vacuum degree to be 400mbar, and the average residence time to be 10min to obtain the slurry C.

S5: and (3) extrusion reaction: adding the slurry C and the reaction liquid D into a feed inlet of an extruder, controlling the temperature of the extruder to be 220 ℃, the vacuum degree to be 15mbar and the retention time to be 10min, carrying out the graft chain end group thermal polymerization reaction in the extruder and devolatilizing to obtain the polymethyl methacrylate particles. The results of the resin property test are shown in Table 2, and the resin light heat release test is shown in Table 3 and FIG. 1.

Example 3

S1: adding 5700g of methyl methacrylate, 300g of 2-vinylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of n-octyl mercaptan into a batching tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; adding 120g of 4-vinylaniline into the batching tank C, diluting the 4-vinylaniline to 40% mass concentration by using 360g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

S2: first-order reaction: firstly, adding the reaction liquid A into a fully-mixed flow high-pressure reaction kettle A, controlling the reaction temperature to be 135 ℃ to carry out polymerization reaction, and controlling the average residence time to be 3h to obtain a section of prepolymerization slurry A with the conversion rate of 60%.

Example 4

S1: adding 5700g of methyl methacrylate, 300g of 3-vinylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of n-octyl mercaptan into a batching tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; adding 240g of 4-vinylaniline into the material preparation tank C, diluting the mixture to 40% mass concentration by using 360g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was added to the feed tank D, and the mixture was diluted to 50% by mass with 80g of ethylbenzene and sufficiently stirred for 10min to prepare a reaction solution D.

S2, primary reaction: firstly, adding the reaction liquid A into a fully-mixed flow high-pressure reaction kettle A, controlling the reaction temperature to be 135 ℃ to carry out polymerization reaction, and controlling the average residence time to be 3h to obtain a section of prepolymerization slurry A with the conversion rate of 60%.

S3, secondary reaction: and (3) simultaneously adding the prepolymerization slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, controlling the reaction temperature to be 165 ℃, the vacuum degree to be 700mbar, and the average residence time to be 1.5h to obtain slurry B, wherein the conversion rate is 90%.

S4 end capping reaction: adding the slurry B and the reaction liquid C into an extrusion flow reactor C through a static mixer, controlling the reaction temperature to be 190 ℃, controlling the vacuum degree to be 600mbar, and controlling the average residence time to be 10min to obtain the slurry C.

S5 extrusion reaction: adding the slurry C and the reaction liquid D into a feed inlet of an extruder, controlling the temperature of the extruder to be 220 ℃, the vacuum degree to be 15mbar and the retention time to be 10min, carrying out the graft chain end group thermal polymerization reaction in the extruder and devolatilizing to obtain the polymethyl methacrylate particles. The results of the resin property test are shown in Table 2, and the resin light heat release test is shown in Table 3 and FIG. 1.

Example 5

S1: adding 5700g of methyl methacrylate, 300g of N-allylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of N-octyl mercaptan into a batching tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; adding 240g of 4-vinylaniline into the material preparation tank C, diluting the mixture to 40% mass concentration by using 360g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

Example 6

S1: adding 5700g of methyl methacrylate, 300g of 4-vinylaniline, 1.8g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 21g of n-octyl mercaptan into a material preparation tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 1200g of aniline, 420g of methacrylic acid and 0.12g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; adding 300g of 4-vinylaniline into the batching tank C, diluting the 4-vinylaniline to 40% mass concentration by using 450g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 40g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 40g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

S2: first-order reaction: firstly, adding the reaction solution A into a fully mixed flow high-pressure reaction kettle A, controlling the reaction temperature to be 135 ℃ to carry out polymerization reaction, and keeping the reaction temperature for 2 hours to obtain a section of pre-polymerization slurry A with the conversion rate of 55%.

S3: and (3) secondary reaction: and (3) simultaneously adding the prepolymerization slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, controlling the reaction temperature at 165 ℃, the vacuum degree at 600mbar, and the average residence time at 1.5h to obtain slurry B, wherein the conversion rate is 85%.

S5: and (3) extrusion reaction: adding the slurry C and the reaction liquid D into a feed inlet of an extruder, controlling the temperature of the extruder to be 200 ℃, the vacuum degree to be 15mbar and the retention time to be 10min, carrying out the graft chain end group thermal polymerization reaction in the extruder and devolatilizing to obtain the polymethyl methacrylate particles. The results of the resin property test are shown in Table 2, and the resin light heat release test is shown in Table 3 and FIG. 1.

Example 7

S1: adding 5700g of methyl methacrylate, 300g of N-allylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of N-octyl mercaptan into a batching tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 300g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide into the material preparing tank B, and fully stirring for 10min to prepare reaction liquid B; adding 240g of 4-vinylaniline into the material preparation tank C, diluting the mixture to 40% mass concentration by using 360g of ethylbenzene, and fully stirring the mixture for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

S2: first-order reaction: firstly, adding the reaction solution A into a fully mixed flow high-pressure reaction kettle A, controlling the reaction temperature to be 140 ℃ to carry out polymerization reaction, and keeping the average residence time for 3 hours to obtain a section of pre-polymerization slurry A with the conversion rate of 65%.

S3: and (3) secondary reaction: and (3) simultaneously adding the prepolymerization slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, and controlling the reaction temperature to be 160 ℃, the vacuum degree to be 600mbar and the average residence time to be 2 hours to obtain slurry B, wherein the conversion rate is 90%.

S4: end capping reaction: adding the slurry B and the reaction liquid C into an extrusion flow reactor C through a static mixer, controlling the reaction temperature to be 195 ℃, the vacuum degree to be 400mbar and the average residence time to be 10min, and obtaining the slurry C.

Example 8

S1: adding 5700g of methyl methacrylate, 300g of N-allylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of N-octyl mercaptan into the batching tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; adding 240g of N-allylaniline into the preparation tank C, diluting the N-allylaniline with 360g of ethylbenzene to 40% of mass concentration, and fully stirring for 10min to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

Comparative example 1

In contrast to example 3, comparative example 1 was tested for its ability to absorb light and release heat without the addition of a blocking agent.

S1: adding 5700g of methyl methacrylate, 300g of 4-vinylaniline, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of n-octyl mercaptan into a batching tank A, and fully stirring for 10min to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring for 10min to prepare reaction liquid B; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred for 10 minutes to prepare a reaction solution D.

S3: and (3) secondary reaction: and simultaneously adding the prepolymerization slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, and controlling the reaction temperature to be 165 ℃, the vacuum degree to be 600mbar and the average residence time to be 1.5h to obtain the slurry B.

S4: extrusion devolatilization: adding the slurry B and the reaction liquid D into a feed inlet of an extruder, controlling the temperature of the extruder to be 220 ℃, the vacuum degree to be 15mbar and the retention time to be 10min, and devolatilizing to obtain the polymethyl methacrylate particles. The results of the resin property test are shown in Table 2, and the resin light heat release test is shown in Table 3 and FIG. 1.

Comparative example 2

In contrast to example 3, this example was tested for light transmittance and photothermal effect without adding an amino group-containing monomer copolymerized with methyl methacrylate in S1 and S2.

S1: adding 5700g of methyl methacrylate, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of n-octyl mercaptan into the material preparation tank A, and fully stirring to prepare a reaction liquid A; adding 600g of aniline, 300g of methacrylic acid and 0.3g of dicumyl peroxide material into the material preparation tank B, and fully stirring to prepare a reaction solution B; adding 240g of 4-vinylaniline into the batching tank C, diluting the 4-vinylaniline with 360g of ethylbenzene to 40% of mass concentration, and fully stirring to prepare a reaction solution C; 80g of t-butyl hydroperoxide was charged into the charge tank D, and the mixture was diluted with 80g of ethylbenzene to 50% by mass concentration and sufficiently stirred to prepare a reaction solution D.

Comparative example 3

Compared with example 3, the comparative example shows that the antifogging polymethyl methacrylate prepared by the patent has an outstanding photo-thermal effect by comparing common PMMA with antifogging PMMA.

S1: adding 5700g of methyl methacrylate, 300g of methyl acrylate, 1.2g of tert-butyl peroxy-3, 5, 5-trimethylhexanoate and 19.2g of n-octyl mercaptan into the batching tank A, and fully stirring for 10min to prepare a reaction liquid A; 95g of methyl methacrylate, 5g of methyl acrylate and 0.3g of dicumyl peroxide were charged into the compounding tank B, and the mixture was sufficiently stirred for 10 minutes to prepare a reaction solution B.

S3: and (3) secondary reaction: and (3) simultaneously adding the pre-polymerized slurry A and the reaction liquid B into a fully mixed flow negative pressure reactor B, controlling the reaction temperature to be 165 ℃ and the average residence time to be 1.5h to obtain slurry B, wherein the conversion rate is 75%.

S4: and (3) tertiary reaction: adding the slurry B into the reactor C, controlling the reaction temperature to be 190 ℃ and the average residence time to be 10min to obtain the slurry C, wherein the conversion rate is 80%.

S5: extrusion devolatilization: adding the slurry B into a feed inlet of an extruder, controlling the temperature of the extruder at 220 ℃, the vacuum degree at 15mbar, and the retention time at 10min, and devolatilizing to obtain the polymethyl methacrylate particles. The results of the resin property test are shown in Table 2, and the resin light heat release test is shown in Table 3 and FIG. 1.

TABLE 2 examples and comparative examples correspond to polymer ratios and optical properties

TABLE 3 endothermic exothermic Properties of polymers corresponding to examples and comparative examples

As can be seen from examples 1-8, 4-vinylaniline, either as a comonomer or as a capping agent, was more reactive than N-allylaniline; the extrusion polymerization temperature has some influence on the end group polymerization, and the temperature is too low, the half life of the initiator is too long, so that the end group polymerization is insufficient, and 220 ℃ is preferred; the higher the proportion of copolymerized aniline-containing monomers or the higher the proportion of grafted aniline, the stronger the photothermal effect; the end-capping reagent ratio has an upper dosage limit, which is in corresponding relation with the copolymerized aniline-containing monomer. The polymerization process conditions in the S2-S4 steps have relatively little effect on the final polymer properties, mainly for the purpose of controlling the material viscosity during the reaction and the conversion per step.

As can be seen from example 5 and comparative examples 1 and 3, PMMA, which is commonly used, has substantially no ability to absorb light and generate heat. Polymethyl methacrylate obtained by means of copolymerization and grafting of aniline alone without endcapping has substantially no photothermal effect.

As can be seen from the example 4 and the comparative example 2, the polymethyl methacrylate and the polyaniline are incompatible, the light transmittance is only 70%, and the light transmittance of more than 90% can be realized only by introducing a copolymer monomer containing a phenylamino group on the main chain of the polymethyl methacrylate, so that the light transmittance has the practical application requirement.

Claims

1. An antifogging polymethyl methacrylate is characterized in that the raw material of the polymethyl methacrylate comprises the following components:

I. monomeric methyl methacrylate: 90-99 parts by mass;

II. Comonomer (b): 1-10 parts by mass of a monomer containing aniline;

III, pH regulator: 1-10 parts by mass of an acrylic group-containing monomer;

IV, grafting monomer: 1-30 parts of aniline;

v, end capping agent: 1-5 parts by mass of 4-vinylaniline and/or N-allylaniline;

the structural formula of the comonomer of the component II is as follows:

wherein R is ₁ Is propenyl and R ₂ 、R ₃ 、R ₄ Is hydrogen, or R ₁ Is hydrogen and R ₂ 、R ₃ 、R ₄ One is vinyl and the other two are hydrogen;

the proportion of the aniline-containing monomer in the polymethyl methacrylate is 1-10wt%, the polymerization proportion of aniline on a graft chain in the polymethyl methacrylate is 1-25wt%, and the proportion of the end-capping agent in the polymethyl methacrylate is 1-5wt%, wherein the proportion of methyl methacrylate participating in main chain polymerization is 100 wt%.

2. The antifog polymethyl methacrylate according to claim 1, wherein the raw material of the polymethyl methacrylate comprises the following components:

I. monomeric methyl methacrylate: 92-97 parts by mass;

II. Comonomer (b): 3-8 parts by mass of a monomer containing aniline;

III, pH regulator: 5-7 parts by mass of an acrylic group-containing monomer;

IV, grafting monomer: 5-20 parts of aniline;

v, end capping agent: 2-4 parts by mass of 4-vinylaniline and/or N-allylaniline;

the comonomer of the component II is 4-vinyl aniline and/or N-allyl aniline.

3. The antifog polymethyl methacrylate of claim 1, wherein the weight average molecular weight of the polymethyl methacrylate is 50,000-300,000;

and/or the cross-linking density characteristic value of the polymethyl methacrylate is 1.01-1.05.

4. The anti-fog type polymethyl methacrylate as claimed in claim 1, wherein the weight average molecular weight of the polymethyl methacrylate is 50,000-200,000.

5. The anti-fog type polymethyl methacrylate as claimed in claim 1, wherein the weight average molecular weight of the polymethyl methacrylate is 70,000-110,000.

6. The antifog polymethyl methacrylate according to claim 1, wherein the proportion of the aniline-containing monomer in the polymethyl methacrylate is 3 to 8wt% based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

7. The antifog polymethyl methacrylate according to claim 1, wherein the proportion of the aniline-containing monomer in the polymethyl methacrylate is 5 to 7wt% based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

8. The antifog polymethyl methacrylate according to claim 1, wherein the polymerization ratio of aniline on the graft chain in the polymethyl methacrylate is 5 to 15wt% based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

9. The antifog polymethyl methacrylate according to claim 1, wherein the polymerization ratio of aniline on the graft chain in the polymethyl methacrylate is 7 to 10wt% based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

10. The antifog polymethyl methacrylate according to claim 1, wherein the ratio of the blocking agent in the polymethyl methacrylate is 3 to 4wt% based on 100wt% of the methyl methacrylate participating in the main chain polymerization.

11. The antifog polymethyl methacrylate of claim 1, wherein the acrylic group-containing monomer of component III is one or more selected from the group consisting of acrylic acid, methacrylic acid, ethacrylic acid, and butylacrylic acid.

12. The anti-fog polymethyl methacrylate of claim 1, wherein the acrylic group-containing monomer of component III is selected from acrylic acid and/or methacrylic acid.

13. The antifog polymethyl methacrylate of claim 1, wherein the acrylic-based monomer of component III is methacrylic acid.

14. A method for preparing the anti-fog polymethyl methacrylate of any one of claims 1 to 13, wherein the method comprises the following steps:

s2: first-order reaction: preparing a main chain structure, and adding the reaction liquid A into a reaction kettle A for polymerization reaction to obtain slurry A;

s3: and (3) secondary reaction: preparing a branched chain structure, adding the slurry A and the reaction liquid B into a reaction kettle B to carry out aniline graft polymerization reaction, and removing redundant methyl methacrylate to obtain slurry B;

s4: end capping reaction: adding the slurry B and the reaction liquid C into a reactor C, and removing redundant aniline and ethylbenzene to obtain slurry C;

s5: and (3) extrusion reaction: adding the slurry C and the reaction liquid D into an inlet of an extruder, and extruding and dicing to obtain antifogging polymethyl methacrylate particles;

wherein the initiator 1, the initiator 2 and the initiator 3 in the S1 are one or more of dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxyacetate, dicumyl peroxide, 1-bis- (tert-butylperoxy) -3,3, 5-trimethylcyclohexane, tert-butyl peroxy-3, 5, 5-trimethylhexanoate, tert-butyl peroxybenzoate, tert-butylperoxycumyl, cumyl peroxide and tert-butyl hydroperoxide.

15. The method of claim 14, wherein the initiator 1 in S1 is t-butyl peroxy-3, 5, 5-trimethylhexanoate, the initiator 2 is dicumyl peroxide, and the initiator 3 is t-butyl hydroperoxide;

and/or, the chain transfer agent S1 is one or more of n-butyl mercaptan, tert-butyl mercaptan, n-octyl mercaptan, iso-octyl mercaptan, n-dodecyl mercaptan and tert-dodecyl mercaptan.

16. The method as claimed in claim 14, wherein the chain transfer agent of S1 is n-octyl mercaptan.

17. The method according to claim 15, wherein the initiator 1 is added in the S1 reaction liquid a in an amount of 0.01 to 0.05 parts by mass based on 100 parts by mass of a monomer comprising 100 parts by mass of methyl methacrylate and an amino group-containing monomer; reaction solution B the initiator 2 was added in an amount of 1X 10 based on 100 parts by mass of the monomers ^-3 -1×10 ^-2 The monomer comprises 100 parts by mass of methyl methacrylate and an aniline-containing monomer, wherein the 100 parts by mass of the monomer comprises 100 parts by mass of the methyl methacrylate and the aniline-containing monomer; reaction solution D the amount of the initiator 3 added is 1 to 2 parts by mass based on 100 parts by mass of the slurry C;

the addition ratio of the chain transfer agent is 0.1-0.4 parts by mass based on 100 parts by mass of the monomer, and the 100 parts by mass of the monomer are 100 parts by mass of methyl methacrylate and a monomer containing an aniline group.

18. The method according to claim 14, wherein the initiator 1 is added in the S1 reaction liquid a in an amount of 0.02 to 0.03 parts by mass based on 100 parts by mass of a monomer comprising 100 parts by mass of methyl methacrylate and a monomer comprising an aniline group; reaction solution B the initiator 2 was added in an amount of 2X 10 based on 100 parts by mass of the monomers ^-3 -5×10 ^-3 The monomer comprises 100 parts by mass of methyl methacrylate and an aniline-containing monomer, wherein the 100 parts by mass of the monomer comprises 100 parts by mass of the methyl methacrylate and the aniline-containing monomer;

the addition ratio of the chain transfer agent is 0.2-0.35 parts by mass based on 100 parts by mass of the monomer, and the 100 parts by mass of the monomer are 100 parts by mass of methyl methacrylate and a monomer containing an aniline group.

19. The method as claimed in claim 14, wherein the reaction kettle A in S2 is a fully mixed flow high pressure reaction kettle; controlling the temperature of the reaction kettle to be 120-150 ℃; the sizing agent A mainly comprises methyl methacrylate and a copolymer D containing an aniline monomer, and also comprises methyl methacrylate and the aniline monomer;

and/or the S3 reaction kettle B is a fully mixed flow reaction kettle; controlling the reaction temperature to be 150 ℃ and 180 ℃; controlling the vacuum degree to be more than 600 mbar; the residual methyl methacrylate content in slurry B was <1000 ppm; the slurry B mainly comprises a polymer E obtained by grafting aniline with polymer D side chain aniline groups in S1, and comprises aniline and acrylic group-containing monomers;

and/or adding the material in the S4 into a reactor C through a static mixer; controlling the reaction temperature to be 180 ℃ and 200 ℃; the vacuum degree is 400 and 600 mbar; removing the redundant aniline and ethylbenzene until the aniline content is less than 5000ppm and the ethylbenzene content is less than 15%; the average retention time is 10-30 min; the slurry C mainly comprises a polymer F obtained by terminating the graft chain end of the polymer E in S3 by a monomer containing an aniline, and also comprises ethylbenzene and a terminating agent;

and/or the extruder temperature in S5 is 200-220 ℃.

20. Use of an antifogging polymethylmethacrylate according to any one of claims 1 to 13 or prepared by the method according to any one of claims 14 to 19 for materials in the fields of spectacles, goggles, automobiles and lighting.