CN102746627A - Polylactic acid and diatomite composite and preparation method thereof - Google Patents

Abstract

The invention discloses polylactic acid and diatomite composite and a preparation method thereof. The polylactic acid and diatomite composite is obtained by mixing and extruding the following raw materials including, by weight, 60-80 parts of polylactic acid, 20-40 parts of diatomite, 1.2-1.9 parts of plasticizer, 0.2-0.7 part of activator, 1-2 parts of coupling reagent and 0.2-0.3 part of antioxidant. The polylactic acid and diatomite composite obtained can be formed in brown naturally without addition of chemical pigment, is excellent in performance indexes, the tensile breaking strength is 45-70MPa, the tensile modulus ranges from 3500MPa to 4500MPa, the bending strength is 85-110MPa, the bending modulus ranges from 5000MPa to 7000MPa, and heat-resistant temperature can be up to 95 DEG C or above. The polylactic acid and diatomite composite containing diatomite can improve water and fertilizer retention capability of soil after being subjected to biodegradation.

Description

POLYACTIC ACID, diatomite composite material and preparation method thereof

Background technology

The waste that Plastic Packaging Materials produces has caused the concern of the whole society day by day to the negative impact that environment brings, and therefore, researches and develops all kinds of novel ecological environment-friendly materials and has obtained bigger progress, and some material has begun suitability for industrialized production.For example starch plastics, POLYACTIC ACID etc.

POLYACTIC ACID full name is Poly Lactic Acid (PLA), has another name called the W-Gum resin, is a kind of polylactide.POLYACTIC ACID is a multiduty high molecular polymer, forms nontoxicity by extracting starch → by fermentation → anhydrate → process manufacturings such as polymerization in the plant fully.Be a kind of reproducible resource, can effectively substitute non-renewable petrochemical industry resource.

Prepare degradable plastics with mineral filler and additive modification POLYACTIC ACID; It is the problem that scientific research circle in recent years and manufacturing enterprise are researching and solving always; For example number of patent application is 201010169771.5 to disclose " a kind of polylactic acid modified material and preparation method thereof "; Wherein mineral filler is a kind of or its mixture in starch, talcum powder, mica, lime carbonate, polynite, the clay; The patent No. is 20109050016.2 to disclose " a kind of polylactic acid degradable material and preparation method thereof " for another example; What wherein mineral filler was adopted is talcum powder, mica, lime carbonate, polynite, clay, owing to talcum powder, mica, lime carbonate, polynite, big, the Heavy Weight of clay density, generally only is fit to do membrane-based article.

Zeyssatite molecular formula SiO ₂, by unbodied SiO ₂Form; Zeyssatite generally is to be formed by the dead later silicate remains of the unicellular algae that is referred to as diatom; It has some particular performances, like: porousness, lower density, bigger surface-area, relative incompressibility and chemicalstability, pH value is neutral, nontoxic, suspension property is good, absorption property is strong.

Summary of the invention:

Technical problem to be solved by this invention is: to present POLYACTIC ACID poor processability; Thermotolerance is not enough; Can not satisfy the problem of widespread use; Can only make the limitation of membrane-based article to present polylactic acid modified product simultaneously, with POLYACTIC ACID and zeyssatite be main raw material through modification, mix, extrude and obtain a kind of matrix material, this matrix material is suitable for fields such as Industrial products packing, food product pack, the interior holder of electronic product, gift and toy.Because zeyssatite has the stable dark brown of a kind of pure natural, therefore, goods need not to carry out any dyeing or the decolouring processing can be used safety, environmental protection.

The present invention realizes through following technical scheme:

POLYACTIC ACID, diatomite composite material are obtained via mixing, extruding by following raw materials in part by weight;

POLYACTIC ACID 60-80 part zeyssatite 20-40 part softening agent 1.2-1.9 part promoting agent 0.2-0.7 part coupling agent 1-2 part oxidation inhibitor 0.2-0.3 part.

The further improvement project of the present invention is that described POLYACTIC ACID molecular-weight average is 100,000-200,000.

The present invention further improvement project is that described softening agent is one or more mixing in glycerine, mono-glycerides, the sorbyl alcohol.

The present invention further improvement project is that described promoting agent is hard ester acid.

The present invention further improvement project is that described coupling agent is one or more mixing in titanic acid ester, aluminic acid ester, the aluminium titanium mixture.

The present invention further improvement project is that described oxidation inhibitor is that 168 models are three ［ 2.4-di-tert-butyl-phenyl ］ phosphorous acid esters or are i.e. four (β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid) of 1010 models.

Prepare the method for above-mentioned POLYACTIC ACID, diatomite composite material, comprise the steps:

(1) zeyssatite is lower than 10% through sunlight seasoning to water cut;

(2) calcining: zeyssatite is put into incinerator, and calcining temperature is controlled at below 500 ℃, and the zeyssatite water cut after the burning is lower than 1%;

(3) superfine grinding: obtain the above zeyssatite of 1000 orders;

(4) by the described proportioning of claim 1, POLYACTIC ACID, zeyssatite, softening agent, promoting agent, coupling agent, oxidation inhibitor are added in (SRL type) high-speed mixer, under 120-130 ℃ of condition, mix, be cooled to then below 80 ℃;

(5) mixture that step (4) is obtained is sent into the twin screw extruder melt blending, and extrusion temperature 180-230 ℃, with the air-cooled butt formula of die face granulating.

The present invention compared with prior art has following obvious advantage:

One, POLYACTIC ACID diatomite composite material of the present invention need not add chemical pigment, can become coffee-like naturally.Polymkeric substance of the present invention owing to contain zeyssatite, can improve the soil water-reataining fertilizer-keeping ability after biological degradation.

Two, performance index of the present invention are excellent: tensile break strength (MPa) is 45-70, and tensile modulus (MPa) is 3500-4500, and flexural strength (MPa) is 85-110, and modulus in flexure (MPa) is 5000-7000, and heat resisting temperature reaches more than 95 ℃.

Embodiment

In following examples, used POLYACTIC ACID is polylactide (PLA), and molecular-weight average is 10-20 ten thousand; Zeyssatite originates from Shengzhou, Zhejiang Province city.

Embodiment 1

Get 0.2 part in 1 part of oxidation inhibitor of 0.2 part of coupling agent of 1.2 portions of promoting agents of 20 parts of softening agent of 60 parts of zeyssatite of POLYACTIC ACID.

Described softening agent is a mono stearate glyceryl ester, and described promoting agent is hard ester acid, and described coupling agent is a titanic acid ester, and said oxidation inhibitor is three ［ 2.4-di-tert-butyl-phenyl ］ phosphorous acid ester.

Its preparation comprises the steps:

(1) zeyssatite is lower than 10% through sunlight seasoning to water cut;

(2) calcining: zeyssatite is put into incinerator, and calcining temperature is controlled at below 500 ℃, and the zeyssatite water cut after the burning is lower than 1%;

(3) superfine grinding: obtain 1200 order zeyssatite;

(4) by above-mentioned proportioning, POLYACTIC ACID, zeyssatite, softening agent, promoting agent, coupling agent, oxidation inhibitor are added in (SRL type) high-speed mixer, under 120-130 ℃ of condition, mix, be cooled to then below 80 ℃;

(5) mixture that step (4) is obtained is sent into the twin screw extruder melt blending, and extrusion temperature 180-230 ℃, with the air-cooled butt formula of die face granulating.

POLYACTIC ACID, the diatomite composite material of present embodiment are processed particle shape, and then become goods (for example: cutter, fork etc.) with the injection moulding of this particle.

Through the JISK7127 determination of experimental method: tensile break strength (MPa) is 65, and tensile modulus (MPa) is 4500, and flexural strength (MPa) is 105, and modulus in flexure (MPa) is 6000,90 ℃ of heat resisting temperatures.

Embodiment 2

Get 0.3 part in 1.5 parts of oxidation inhibitor of 0.5 part of coupling agent of 1.5 portions of promoting agents of 30 parts of softening agent of 70 parts of zeyssatite of POLYACTIC ACID.

Described softening agent is glycerine and mono-glycerides mixture, can mix by arbitrary proportion, presses 1:1 in the present embodiment and mixes; Described promoting agent is hard ester acid; Described coupling agent is the aluminic acid ester, and said oxidation inhibitor is four (β-(3, the 5-di-tert-butyl-hydroxy phenyl) propionic acid).

All the other are implemented like embodiment 1.

POLYACTIC ACID, the diatomite composite material of present embodiment are processed particle shape, and then become goods (for example: cutter, fork, cup, bowl etc.) with the injection moulding of this particle.

Through the JISK7127 determination of experimental method: tensile break strength (MPa) is 70, and tensile modulus (MPa) is 4500, and flexural strength (MPa) is 110, and modulus in flexure (MPa) is 6000,95 ℃ of heat resisting temperatures.

The POLYACTIC ACID that embodiment 1 obtains, diatomite composite material, with talcum powder, lactic acid composite material (with the zeyssatite in the talcum powder alternate embodiment 1, all the other conditions are constant), detect the index contrast as follows under the same conditions:

?	The talcum powder POLYACTIC ACID	The zeyssatite POLYACTIC ACID
			Tensile break strength (MPa)	48	65
Tensile modulus (MPa)	3000	4500
			Flexural strength (MPa	83	105
Modulus in flexure (MPa)	3828	6000
			Heat resisting temperature	65	90
Finished color	White	The natural coffee look

The data that from above-mentioned table, provide can know that each item index of the present invention all is superior to talcum powder, lactic acid composite material, are fit to make disposable tableware, perhaps make the storage package box of some materials etc.As " owing to contain zeyssatite, after biological degradation, improving the soil water-reataining fertilizer-keeping ability " described in the top advantage, with POLYACTIC ACID, the diatomite composite material of zeyssatite as the additive preparation, raw material is easy to get, and is with low cost simultaneously.

Claims (7)

1. POLYACTIC ACID, diatomite composite material is characterized in that: following raw materials in part by weight obtains via mixing, extruding;

POLYACTIC ACID 60-80 part zeyssatite 20-40 part softening agent 1.2-1.9 part promoting agent 0.2-0.7 part coupling agent 1-2 part oxidation inhibitor 0.2-0.3 part.

2. like claims 1 described POLYACTIC ACID, diatomite composite material, it is characterized in that: described POLYACTIC ACID molecular-weight average is 100,000-200,000.

3. like claims 1 described POLYACTIC ACID, diatomite composite material, it is characterized in that: described softening agent is one or more mixing in glycerine, mono-glycerides, the sorbyl alcohol.

4. like claims 1 described POLYACTIC ACID, diatomite composite material, it is characterized in that: described promoting agent is hard ester acid.

5. like claims 1 described POLYACTIC ACID, diatomite composite material, it is characterized in that: described coupling agent is one or more mixing in titanic acid ester, aluminic acid ester, the aluminium titanium mixture.

6. like claims 1 described POLYACTIC ACID, diatomite composite material, it is characterized in that: described oxidation inhibitor is 168 models or is 1010 models.

7. prepare the method for claims 1 to 6 said POLYACTIC ACID, diatomite composite material, it is characterized in that comprising the steps:

(1) zeyssatite is lower than 10% through sunlight seasoning to water cut;

(2) calcining: zeyssatite is put into incinerator, and calcining temperature is controlled at below 500 ℃, and the zeyssatite water cut after the burning is lower than 1%;

(3) superfine grinding: obtain the above zeyssatite of 1000 orders;

(4) by the described proportioning of claim 1, POLYACTIC ACID, zeyssatite, softening agent, promoting agent, coupling agent, oxidation inhibitor are added in the high-speed mixer, under 120-130 ℃ of condition, mix, be cooled to then below 80 ℃;

(5) mixture that step (4) is obtained is sent into the twin screw extruder melt blending, and extrusion temperature 180-230 ℃, with the air-cooled butt formula of die face granulating.