CN103483788B - A kind of composite toughening method of modifying of the polylactic acid based on crystallization control - Google Patents
A kind of composite toughening method of modifying of the polylactic acid based on crystallization control Download PDFInfo
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- CN103483788B CN103483788B CN201310406705.9A CN201310406705A CN103483788B CN 103483788 B CN103483788 B CN 103483788B CN 201310406705 A CN201310406705 A CN 201310406705A CN 103483788 B CN103483788 B CN 103483788B
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- polylactic acid
- vinyl acetate
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- acetate copolymer
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- 229920000747 poly(lactic acid) Polymers 0.000 title claims abstract description 68
- 239000004626 polylactic acid Substances 0.000 title claims abstract description 68
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000002425 crystallisation Methods 0.000 title claims abstract description 14
- 230000008025 crystallization Effects 0.000 title claims abstract description 14
- 239000002131 composite material Substances 0.000 title claims abstract description 8
- 239000005038 ethylene vinyl acetate Substances 0.000 claims abstract description 34
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims abstract description 34
- VOZRXNHHFUQHIL-UHFFFAOYSA-N glycidyl methacrylate Chemical compound CC(=C)C(=O)OCC1CO1 VOZRXNHHFUQHIL-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000000463 material Substances 0.000 claims abstract description 13
- 238000002156 mixing Methods 0.000 claims abstract description 12
- 238000007731 hot pressing Methods 0.000 claims abstract description 6
- 238000003825 pressing Methods 0.000 claims abstract description 6
- 238000001291 vacuum drying Methods 0.000 claims abstract description 6
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims description 2
- 229940117958 vinyl acetate Drugs 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 3
- 238000012545 processing Methods 0.000 abstract description 3
- 238000001035 drying Methods 0.000 abstract description 2
- 238000009776 industrial production Methods 0.000 abstract description 2
- 239000002861 polymer material Substances 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 6
- 230000003014 reinforcing effect Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 238000000465 moulding Methods 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 2
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 description 2
- 229920002521 macromolecule Polymers 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 239000004014 plasticizer Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229920003232 aliphatic polyester Polymers 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- DQXBYHZEEUGOBF-UHFFFAOYSA-N but-3-enoic acid;ethene Chemical compound C=C.OC(=O)CC=C DQXBYHZEEUGOBF-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001938 differential scanning calorimetry curve Methods 0.000 description 1
- 230000008570 general process Effects 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000004310 lactic acid Substances 0.000 description 1
- 235000014655 lactic acid Nutrition 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- 239000002991 molded plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 239000012745 toughening agent Substances 0.000 description 1
Abstract
The invention discloses the composite toughening method of modifying of a kind of polylactic acid based on crystallization control, belong to technical field of polymer materials. Polylactic acid and ethylene-vinyl acetate copolymer are previously placed in the vacuum drying oven of 60 DEG C and dry 12h, then by the polylactic acid of drying and ethylene-vinyl acetate copolymer under the blending temperature of 170-180 DEG C, it is sequentially added into polylactic acid, ethylene-vinyl acetate copolymer and glycidyl methacrylate, obtains intermingling material; The product of above-mentioned blended banburying being cooled down is placed in mould, on vulcanizing press with 170-180 DEG C at preheating be sequentially carried out hot pressing in 2-3 minute after 2-4 minute and within 3-5 minute, cold pressing and can reach the purpose of the crystallization control to polylactic acid and toughening modifying. The technological process that the present invention prepares the polylactic acid of good-toughness is simple, and processing characteristics is excellent, and cost is low and can realize large-scale industrial production.
Description
Technical field
The invention belongs to technical field of polymer materials, specifically the composite toughening method of modifying of a kind of polylactic acid based on crystallization control.
Background technology
Polylactic acid is a kind of with reproducible plant resources for raw material, it is chemically synthesized the Biodegradable high molecular of preparation, the processing and forming such as the thermoplasticity of polylactic acid can carry out extruding as these macromolecules of PP, PS and PET on general process equipment, injection moulding. It addition, polylactic acid also has biocompatibility and the biological degradability of uniqueness, accordingly, as a kind of Biodegradable high molecular, polylactic acid has become macromolecule academia and the focus of industrial circle concern.
The intensity of polylactic acid and rigidity are high, but toughness and impact resistance are poor, are a kind of hard and crisp material under room temperature. Therefore, the toughness reinforcing plasticization and modification of polylactic acid is always up the important subject of its marketization.
Blending and modifying is a kind of relatively inexpensive and easy method of modifying. Blending and modifying is polylactic acid, the good polymer of toughness jointly to be mixed, thus reaching a kind of method of the toughness reinforcing purpose of polylactic acid. Blending modification method can be effectively improved the toughness of polylactic acid, there is also the problems such as poor compatibility between blend components, blended rear system mechanical property be undesirable but then.
Through the retrieval of prior art is found, in order to improve the toughness of polylactic acid, people have carried out many research work, as adopted polylactic acid and other aliphatic polyesters to carry out compound, but expensive, it is difficult to accepted by market. And ethylene-vinyl acetate copolymer is cheap and easy to get, and there is fabulous toughness, the toughness reinforcing of polylactic acid can be applied to. Japan Patent JP-2007063435 proposes to prepare moulded products after blended to polylactic acid, ethylene-vinyl acetate copolymer, although the impact strength of blend alloy is improved, but the crystal property of polylactic acid does not improve. (the plastics science and technology such as Fu Xuejun, 2007,35(7), 50) ethylene-vinyl acetate copolymer is adopted to carry out toughness reinforcing to polylactic acid, and adopt plasticizer phthalic acid dioctyl ester (DOP) to improve the biphase compatibility, but DOP has potential carcinogenecity, and the application of its polylactic acid-based product has been also affected by restriction, and said method also makes the low difficult forming of polylactic acid crystal degree, molding cycle is long.
Summary of the invention
The present invention is directed to prior art above shortcomings, it is provided that the composite toughening method of modifying of a kind of polylactic acid based on crystallization control, simple realizing method step, further increase the toughness of composite while the suitability is strong.
The present invention is achieved by the following technical solutions, and the present invention, by adding glycidyl methacrylate and ethylene-vinyl acetate copolymer in polylactic acid, realizes the crystallization control to polylactic acid and toughening modifying.
A kind of composite toughening method of modifying of the polylactic acid based on crystallization control, carry out as steps described below: polylactic acid and ethylene-vinyl acetate copolymer are previously placed in the vacuum drying oven of 60 DEG C and dry 12h by (1), (2) then by the polylactic acid of drying and ethylene-vinyl acetate copolymer under the blending temperature of 170-180 DEG C, it is sequentially added into polylactic acid, ethylene-vinyl acetate copolymer and glycidyl methacrylate, and with mixing 8-10 minute of the speed of 60-80 rpm, obtain PLA/EVA intermingling material; (3) the product cooling of above-mentioned blended banburying is placed in mould, on vulcanizing press with 170-180 DEG C at preheating be sequentially carried out hot pressing in 2-3 minute and cold pressing for 3-5 minute after 2-4 minute, pressure is 10-15MPa, can reach the purpose of the crystallization control to polylactic acid and toughening modifying.
Parts by weight respectively 80-85 part of wherein said polylactic acid, ethylene vinyl acetate copolymer and glycidyl methacrylate, 10-15 part, 2.5-10 part.
Described polylactic acid melt index is (190 DEG C, 2.16Kg) 10g/min, for instance the polylactic acid that the trade mark is 3051D that Natureworks company produces, density is 1.24g/cm3��
The melt index of described ethylene-vinyl acetate copolymer is (190 DEG C, 2.16Kg) 20g/min, and wherein the content of vinylacetate is 28wt%, for instance the density that Hunan petro-chemical corporation produces is 0.95g/cm3, the trade mark is the ethylene-vinyl acetate copolymer of VA800.
Present invention employs ethylene-vinyl acetate copolymer and glycidyl methacrylate and method, the elasticity that ethylene-vinyl acetate copolymer is good is utilized to carry out toughness reinforcing to polylactic acid, utilize the crystallization behavior of glycidyl methacrylate regulation and control polylactic acid, to improve the elongation at break of material. Material is made to have the feature of high tenacity. Being 85 at polylactic acid, ethylene vinyl acetate copolymer is 15, and when glycidyl methacrylate is 10 mass parts, the elongation at break of intermingling material reaches 215%, and impact strength reaches 97.18J/m. The technological process that the present invention prepares the polylactic acid of good-toughness is simple, and processing characteristics is excellent, and cost is low and can realize large-scale industrial production. The blend obtained can be used for preparing thin film, sheet material and injection-molded plastic product.
Accompanying drawing explanation
Fig. 1 is the DSC curve of lactic acid and blend thereof, wherein 1: polylactic acid; 2: polylactic acid/ethylene-vinyl acetate copolymer; 3: polylactic acid/ethylene-vinyl acetate copolymerization/10% glycidyl methacrylate.
Detailed description of the invention
Below embodiments of the invention being elaborated, the present embodiment is carried out under premised on technical solution of the present invention, gives detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.
Following example material therefor is: polylactic acid: trade mark 3051D, melt index (190 DEG C, 2.16kg) 10g/min, U.S.'s Natureworks product;
Ethylene-vinyl acetate copolymer, trade mark VA800, Hunan petro-chemical corporation of Korea S produces.
Embodiment 1-4
The embodiment of the present invention comprises the following steps:
The first step, is placed in 60 DEG C of vacuum drying ovens dries 12h by polylactic acid, ethylene vinyl acetate copolymer;
Second step, is pre-mixed uniformly by the polylactic acid after dried, ethylene vinyl acetate copolymer and glycidyl methacrylate in table one ratio, then melt blending in (Jiangsu Su Yan science and technology, SU-70c type) banbury. Blending temperature is 180 DEG C, and rotating speed is 80 rpms, and the blended time is 10 minutes;
3rd step, is placed in mould by gained banburying product, preheats 3min, then hot pressing 2min under 10MPa then 3min molding of colding pressing at 180 DEG C, and pressure is 10MPa, by ASTM standard sample preparation, material is carried out performance test. (concrete proportioning is in Table 1)
Comparative example 1
The first step, before blended, be placed in 60 DEG C of vacuum drying ovens dry 12h by polylactic acid, ethylene vinyl acetate copolymer;
Second step, melts the polylactic acid after dried in (Jiangsu Su Yan science and technology, SU-70c type) banbury. Banburying temperature is 180 DEG C, and rotating speed is 80 rpms, and the blended time is 10 minutes;
3rd step, is placed in mould by gained banburying product, preheats 3min, then hot pressing 2min under 10MPa then 3min molding of colding pressing at 180 DEG C, and pressure is 10MPa, by ASTM standard sample preparation, material is carried out performance test.
Comparative example 2
The first step, is placed in 60 DEG C of vacuum drying ovens dries 12h by polylactic acid, ethylene vinyl acetate copolymer;
Second step, is pre-mixed uniformly by the polylactic acid after dried, ethylene vinyl acetate copolymer in table one ratio, then melt blending in (Jiangsu Su Yan science and technology, SU-70c type) banbury. Blending temperature is 180 DEG C, and rotating speed is 80 rpms, and the blended time is 10 minutes;
3rd step, is placed in mould by gained banburying product, preheats 3min, then hot pressing 2min under 10MPa then 3min molding of colding pressing at 180 DEG C, and pressure is 10MPa, by ASTM standard sample preparation, material is carried out performance test.
Table 1 embodiment and comparative example formula (unit is weight portion)
| Embodiment 1 | Embodiment 2 | Embodiment 3 | Embodiment 4 | Comparative example 1 | Comparative example 2 | |
| Polylactic acid | 80 | 85 | 80 | 85 | 100 | 85 |
| Ethylene vinyl acetate copolymer | 15 | 10 | 10 | 15 | 0 | 15 |
| Glycidyl methacrylate | 2.5 | 5 | 7.5 | 10 | 0 | 0 |
Table 2 thickness of sample is 1.0mm, mechanical property result during rate of extension 50mm/min
| Embodiment 1 | Embodiment 2 | Embodiment 3 | Embodiment 4 | Comparative example 1 | Comparative example 2 | |
| Hot strength (MPa) | 40.8 | 35 | 30.32 | 29.13 | 48.3 | 68.5 |
| Elongation at break (%) | 35 | 77 | 93 | 215 | 3 | 24 |
| Notch impact strength (J/m) | 78 | 84 | 92 | 97 | 33 | 73 |
As can be seen from Table 2, adopt this method to add ethylene vinyl acetate copolymer and polylactic acid is carried out toughness reinforcing, when 15 parts of toughener add in 85 parts of polylactic acid, the notch impact strength of polylactic acid is about original 2 times, along with the addition of plasticizer glycidyl methacrylate and increasing of addition, the elongation at break of material and notch impact strength improve, especially elongation at break, the highest improve about 70 times. Ethylene-vinyl acetate copolymer and glycidyl methacrylate improve the toughness of polylactic acid jointly.
The DSC data of table 3 polylactic acid and blend thereof
As can be seen from Figure 1, the endothermic peak of pure polylactic acid is only small, show its before post bake still based on amorphous state, the addition of ethylene-vinyl acetate copolymer fails to improve the crystal property of polylactic acid, can be seen that from Fig. 1 and Biao 3, the addition of the methyl methacrylate of 10% mass parts makes the glass transition temperature of polylactic acid in blend be remarkably decreased, and occur in that cold crystallization peak, the endothermic peak of polylactic acid substantially becomes big, it was shown that the methyl methacrylate Effective Regulation crystallization behavior of polylactic acid.
Claims (1)
1. the composite toughening method of modifying based on the polylactic acid of crystallization control, it is characterized in that carrying out as steps described below: polylactic acid and ethylene-vinyl acetate copolymer are previously placed in the vacuum drying oven of 60 DEG C and dry 12h by (1), (2) then by the polylactic acid after dried and ethylene-vinyl acetate copolymer, and glycidyl methacrylate is pre-mixed uniformly, melt blending in banbury, blending temperature is 170-180 DEG C, rotating speed is 60-80 rpm, the blended time is 8-10 minute, obtains intermingling material; (3) the product cooling of above-mentioned blended banburying is placed in mould, vulcanizing press after preheating 2-4 minute at 170-180 DEG C it is sequentially carried out hot pressing in 2-3 minute and colds pressing for 3-5 minute, pressure is 10-15MPa, can reach the purpose of the crystallization control to polylactic acid and toughening modifying;
Parts by weight respectively 80-85 part of wherein said polylactic acid, ethylene vinyl acetate copolymer and glycidyl methacrylate, 10-15 part, 2.5-10 part;
Described ethylene-vinyl acetate copolymer adopt melt index be 190 DEG C with 2.16Kg time be the ethylene-vinyl acetate copolymer of 20g/min, wherein the content of vinylacetate is 28wt%.
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| CN103265798A (en) * | 2013-06-03 | 2013-08-28 | 山东昊达化学有限公司 | Polylactic acid (PLA) and ethylene-vinyl acetate (EVA) blended composition and formed product thereof |
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| US20080026171A1 (en) * | 2006-07-28 | 2008-01-31 | Alcan Packaging Flexible France | Coextruded film with polylactic acid (PLA) and Ethylene Vinyl Acetate (EVA) |
| US7736560B2 (en) * | 2006-11-02 | 2010-06-15 | Diaserve, Inc. | Biological polymeric compositions and methods related thereto |
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| CN103265798A (en) * | 2013-06-03 | 2013-08-28 | 山东昊达化学有限公司 | Polylactic acid (PLA) and ethylene-vinyl acetate (EVA) blended composition and formed product thereof |
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Effective date of registration: 20240321 Address after: No. 8 Xinchun Road, Yaotang Street, Jintan District, Changzhou City, Jiangsu Province, 213000 Patentee after: Changzhou saipeng biomaterial Technology Co.,Ltd. Country or region after: Zhong Guo Address before: Room 407-2-6, building C, Tian'an Digital City, 588 Changwu South Road, Wujin high tech Industrial Development Zone, Changzhou City, Jiangsu Province 213000 Patentee before: CHANGZHOU XIAOGUO INFORMATION SERVICES Co.,Ltd. Country or region before: Zhong Guo |