CN114181504B - Method for preparing polylactic acid by utilizing modified cellulose nanocrystalline - Google Patents
Method for preparing polylactic acid by utilizing modified cellulose nanocrystalline Download PDFInfo
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- CN114181504B CN114181504B CN202111589594.0A CN202111589594A CN114181504B CN 114181504 B CN114181504 B CN 114181504B CN 202111589594 A CN202111589594 A CN 202111589594A CN 114181504 B CN114181504 B CN 114181504B
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- lactic acid
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- polyethylene glycol
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- 229920002678 cellulose Polymers 0.000 title claims abstract description 55
- 239000001913 cellulose Substances 0.000 title claims abstract description 55
- 239000004626 polylactic acid Substances 0.000 title claims abstract description 54
- 229920000747 poly(lactic acid) Polymers 0.000 title claims abstract description 53
- 238000000034 method Methods 0.000 title claims abstract description 13
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 claims abstract description 82
- 239000004310 lactic acid Substances 0.000 claims abstract description 41
- 235000014655 lactic acid Nutrition 0.000 claims abstract description 41
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000002202 Polyethylene glycol Substances 0.000 claims abstract description 23
- 229920001223 polyethylene glycol Polymers 0.000 claims abstract description 23
- 229920000742 Cotton Polymers 0.000 claims abstract description 13
- 239000000047 product Substances 0.000 claims description 17
- 238000005406 washing Methods 0.000 claims description 14
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 12
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 10
- 239000008367 deionised water Substances 0.000 claims description 9
- 229910021641 deionized water Inorganic materials 0.000 claims description 9
- 239000006185 dispersion Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- 238000002156 mixing Methods 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000007788 liquid Substances 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 7
- 238000001291 vacuum drying Methods 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 238000001914 filtration Methods 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 239000007864 aqueous solution Substances 0.000 claims description 4
- 238000004108 freeze drying Methods 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 4
- -1 polytetrafluoroethylene Polymers 0.000 claims description 4
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 4
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 4
- 239000006228 supernatant Substances 0.000 claims description 4
- 238000002425 crystallisation Methods 0.000 abstract description 17
- 239000002159 nanocrystal Substances 0.000 abstract description 17
- 230000008025 crystallization Effects 0.000 abstract description 15
- 230000009471 action Effects 0.000 abstract description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 abstract description 3
- 238000006482 condensation reaction Methods 0.000 abstract description 2
- 239000002667 nucleating agent Substances 0.000 description 12
- 238000010899 nucleation Methods 0.000 description 10
- 230000006911 nucleation Effects 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 238000007151 ring opening polymerisation reaction Methods 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 230000018044 dehydration Effects 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229920006038 crystalline resin Polymers 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000001727 in vivo Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- JJTUDXZGHPGLLC-UHFFFAOYSA-N lactide Chemical compound CC1OC(=O)C(C)OC1=O JJTUDXZGHPGLLC-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004060 metabolic process Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000002114 nanocomposite Substances 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- 231100000344 non-irritating Toxicity 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/24—Crystallisation aids
Abstract
The invention relates to a method for preparing polylactic acid by utilizing modified cellulose nanocrystalline. According to the invention, firstly, cotton fibers are subjected to acidolysis in lactic acid and hydrochloric acid, on one hand, disordered and amorphous cellulose in the cotton fibers is dissolved, then, under the combined action of lactic acid and hydrochloric acid, part of hydroxyl groups on the surface of cellulose nanocrystals are combined with lactic acid, and lactic acid is grafted onto the cellulose nanocrystals. And then, polyethylene glycol is further grafted onto the cellulose nanocrystalline through condensation reaction of the polyethylene glycol and the lactic acid, so that the cellulose nanocrystalline grafted with the lactic acid and the polyethylene glycol together is obtained, the compatibility of the cellulose nanocrystalline and the polylactic acid is improved, and the crystallization performance and the mechanical property of the polylactic acid are effectively improved.
Description
Technical Field
The invention belongs to the field of polylactic acid, and particularly relates to a method for preparing polylactic acid by utilizing modified cellulose nanocrystals.
Background
Polylactic acid (PLA) is a polymer obtained by polymerizing lactic acid as a main raw material, is a non-toxic, non-irritating, biocompatible and biodegradable high molecular compound, and can participate in metabolism of human body in vivo, and is widely used in the fields of medical treatment, clothing, industry, food packaging industry and the like.
The preparation method of the polylactic acid mainly comprises a direct polycondensation method and a ring-opening polymerization method, wherein the polylactic acid is obtained by direct dehydration condensation of the lactic acid, and the product obtained by the method has lower relative molecular weight, wider molecular weight distribution, easy decomposition and no practical value; the latter depolymerizes the oligomer obtained after lactic acid dehydration condensation under the action of a catalyst to obtain lactide, and then adds the catalyst to carry out ring-opening polymerization to obtain polylactic acid with higher relative molecular mass, and the ring-opening polymerization method has no small molecular byproducts, so that the polymerization reaction degree can be accurately controlled and improved, the molecular weight of the obtained polylactic acid product reaches more than 10 ten thousand, and the performance index of the polylactic acid product reaches the performance requirement of being used as a common structural material, thereby being a general technical process for industrial production of polylactic acid at present.
Theoretically, PLA belongs to a crystalline polymer, and crystallization occurs during cooling in molding processing, but only the properties of semi-crystalline resins can be achieved in practical production, and the degree of crystallization is low and the crystallization speed is slow. If the crystallinity is not improved more, the heat resistance and transparency of the product are affected, for example, the glass transition temperature of low-crystallization PLA is only about 60 ℃, and the crystallization capability of PLA can be improved by modifying PLA, so that the heat resistance, transparency, tensile strength, bending strength and modulus, degradation rate and barrier property can be improved.
However, the nucleation rate and crystallization rate of PLA under homogeneous nucleation conditions are low, and the nucleation speed is increased by adding a nucleating agent, so that the surface free barrier required by PLA nucleation can be reduced by adding the nucleating agent, and the PLA is heterogeneous for nucleation, thereby shortening the crystallization time, increasing the crystallization rate and promoting the crystallization of PLA. In addition, the nucleation mobility of the molecular chains is increased by adding a plasticizer, thereby improving the crystallization performance of PLA. The nucleating agent of PLA has the main functions of improving the nucleation density, shortening the semi-crystallization time and reducing the nucleation induction period, and mainly comprises an inorganic nucleating agent and an organic nucleating agent. The inorganic nucleating agent commonly used at present has the advantages of layered silicate, inorganic salts, carbon and the like, and the inorganic nucleating agent has the defects of poor compatibility with PLA, general nucleating effect and low price. While organic nucleating agents have good compatibility and good nucleating effect, but are expensive.
Cellulose nanocrystals are rod-like nanomaterials extracted from cellulose, and are usually separated from the fibers by sulfuric acid or hydrochloric acid, whereby the disordered and semi-crystalline portions of the cellulose are preferentially hydrolyzed during acid treatment, and the crystalline portions are completely retained because they are better resistant to acidolysis, thus obtaining cellulose nanocrystals. The cellulose nanocrystalline has excellent performances of complete biodegradability, low density, high strength and the like, and can be used as a crystallization nucleating agent of PLA. The cellulose nanocrystalline and the polylactic acid are compounded to prepare the nanocomposite to improve the performance of the polylactic acid, so that the application range of the polylactic acid can be effectively enlarged. However, because the cellulose nanocrystals have strong hydrogen bonding effect, the cellulose nanocrystals are easy to aggregate in a solution and are unfavorable for dispersion, so that the application of the cellulose nanocrystals in polylactic acid materials is limited. On the other hand, the nano particles have obvious hydrophilicity, which is not beneficial to the compatibility between cellulose nano crystals and polylactic acid, and the combination of the cellulose nano crystals and polylactic acid brings great challenges.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a method for preparing polylactic acid by utilizing modified cellulose nanocrystals, which comprises the steps of firstly carrying out acidolysis on cellulose fibers by adopting mixed acid of hydrochloric acid and acetic acid to prepare cellulose nanocrystals with lactic acid grafted on the surface, then further improving the dispersibility of the cellulose nanocrystals by modifying the surface of polyethylene glycol, and taking the modified cellulose nanocrystals as a nucleating agent to effectively improve the crystallization property and mechanical property of the polylactic acid.
In order to achieve the aim of the invention, the preparation method of the polylactic acid comprises the following steps:
(1) Uniformly mixing cotton fiber crushed aggregates, 90wt% of lactic acid aqueous solution and 37wt% of concentrated hydrochloric acid, transferring into a polytetrafluoroethylene lining reaction kettle, reacting under a closed condition, washing a product with deionized water, centrifuging to obtain a supernatant, and freeze-drying to obtain lactic acid grafted cellulose nanocrystalline;
(2) Ultrasonically dispersing the lactic acid grafted cellulose nanocrystalline obtained in the step (1) in N, N-dimethylformamide to form stable dispersion liquid, adding polyethylene glycol into the dispersion liquid, reacting for 2-3 days at 110-140 ℃ under continuous stirring, washing the obtained product by ethanol, washing by deionized water, filtering and vacuum drying to obtain cellulose nanocrystalline grafted with lactic acid and polyethylene glycol together;
(3) Mixing the product prepared in the step (2) with polylactic acid according to the mass ratio of 0.1-5:100 is added into a banburying mixer, the temperature is controlled at 150-210 ℃, the rotating speed is 60-150rpm, the heat is preserved for 30-150 min, then the temperature is reduced to 50-70 ℃ and preserved for 1-3h, and then the temperature is reduced to room temperature, thus obtaining the polylactic acid material.
Further, in step (1), cotton fiber particles: 90wt% aqueous lactic acid: the mass ratio of the 37wt% concentrated hydrochloric acid is 1:10-15:0.1-2.
Further, the reaction temperature in the step (1) is 130-160 ℃ and the reaction time is 3-8h.
Further, in the step (2), the vacuum drying temperature is 90-120 ℃ and the drying time is 6-12h.
Further, the mass ratio of the lactic acid grafted cellulose nanocrystalline to the polyethylene glycol in the step (2) is 100:1-5.
Further, the stirring speed in the step (2) is 50-100rpm.
Further, the cooling rate in the step (3) is 5-20 ℃/min.
Compared with the prior art, the invention has the beneficial effects that:
the cellulose contained in cotton fiber contains a large amount of hydroxyl groups, and the invention firstly carries out acidolysis on the cotton fiber in lactic acid and hydrochloric acid, on one hand, the unordered and amorphous cellulose in the cotton fiber is dissolved, then under the combined action of lactic acid and hydrochloric acid, part of hydroxyl groups on the surface of cellulose nanocrystalline are combined with lactic acid, and lactic acid is grafted on the cellulose nanocrystalline. And then, further grafting polyethylene glycol onto the cellulose nanocrystalline through condensation reaction of the polyethylene glycol and the lactic acid to obtain cellulose nanocrystalline grafted with the lactic acid and the polyethylene glycol together, so that the compatibility of the cellulose nanocrystalline and the polylactic acid is improved. The bio-based cellulose nanocrystalline used in the invention has excellent heterogeneous nucleation effect and excellent processing fluidity of polyethylene glycol, and lactic acid is utilized to combine the bio-based cellulose nanocrystalline with the polyethylene glycol, and the bio-based cellulose nanocrystalline is synergistic as a nucleating agent to effectively improve the crystallization property and mechanical property of polylactic acid. The obtained polylactic acid material has crystallinity as high as 52.1%, and tensile strength as high as 45MPa, and shows excellent crystallization property and mechanical property.
Detailed Description
For the purpose of providing a thorough and complete understanding of the present invention, reference will now be made in detail to the present invention with reference to the specific examples, which are included herein to illustrate and provide a further understanding of the invention.
Example 1
(1) Uniformly mixing cotton fiber crushed aggregates, 90wt% of lactic acid aqueous solution and 37wt% of concentrated hydrochloric acid, transferring into a polytetrafluoroethylene lining reaction kettle, reacting for 7 hours at 140 ℃ under a closed condition, washing a product with deionized water, centrifuging to obtain a supernatant, and freeze-drying to obtain lactic acid grafted cellulose nanocrystalline; wherein the cotton fiber particles: 90wt% aqueous lactic acid: the mass ratio of the 37% concentrated hydrochloric acid is 1:10:1, a step of;
(2) Ultrasonically dispersing the lactic acid grafted cellulose nanocrystalline obtained in the step (1) in N, N-dimethylformamide to form stable dispersion liquid, adding polyethylene glycol into the dispersion liquid, reacting for 2 days at 130 ℃ under continuous stirring, and washing the obtained product with ethanol, washing with deionized water, filtering and vacuum drying to obtain cellulose nanocrystalline grafted with lactic acid and polyethylene glycol together; wherein the mass ratio of the lactic acid grafted cellulose nanocrystalline to the polyethylene glycol is 100:4.
(3) Mixing the product prepared in the step (2) with polylactic acid according to a mass ratio of 2:100 is added into a banburying mixer, the temperature is controlled at 180 ℃, the rotating speed is 90rpm, the heat is preserved for 120min, then the temperature is reduced to 60 ℃ at the cooling rate of 15 ℃/min, the heat is preserved for 3h, and then the room temperature is reduced, thus obtaining the polylactic acid material.
Weighing 5mg of sample, placing into a sample crucible, measuring the thermal property of the sample by utilizing a differential scanning calorimeter DSC, heating the sample from 40 ℃ to 200 ℃ at a heating rate of 10 ℃/min, preserving heat at 200 ℃ for 5min, then cooling to 40 ℃ at a cooling rate of 10 ℃/min, heating to 200 ℃ at a heating rate of 10 ℃/min, and measuring and calculating the crystallinity of the sample. Polylactic acid material was cut into test strips 30mm x 8mm, and the test strips were stretched at room temperature at a stretching rate of 10 μm/s, and the tensile strength was measured. The test results are shown in Table 1.
Example 2
(1) Uniformly mixing cotton fiber crushed aggregates, 90wt% of lactic acid aqueous solution and 37wt% of concentrated hydrochloric acid, transferring into a polytetrafluoroethylene lining reaction kettle, reacting for 3 hours at 160 ℃ under a closed condition, washing a product with deionized water, centrifuging to obtain a supernatant, and freeze-drying to obtain lactic acid grafted cellulose nanocrystalline; wherein the cotton fiber particles: 90wt% aqueous lactic acid: the mass ratio of the 37% concentrated hydrochloric acid is 1:15:0.2;
(2) Ultrasonically dispersing the lactic acid grafted cellulose nanocrystalline obtained in the step (1) in N, N-dimethylformamide to form stable dispersion liquid, adding polyethylene glycol into the dispersion liquid, reacting for 3 days at 110 ℃ under continuous stirring, and washing the obtained product with ethanol, washing with deionized water, filtering and vacuum drying to obtain cellulose nanocrystalline grafted with lactic acid and polyethylene glycol together; wherein the mass ratio of the lactic acid grafted cellulose nanocrystalline to the polyethylene glycol is 100:1-2;
(3) Mixing the product prepared in the step (2) with polylactic acid according to a mass ratio of 1:100 is added into a banburying mixer, the temperature is controlled at 200 ℃, the rotating speed is 120rpm, the heat is preserved for 90min, then the temperature is reduced to 50 ℃ at the cooling rate of 10 ℃/min, the heat is preserved for 2h, and then the room temperature is reduced, thus obtaining the polylactic acid material. The test results are shown in Table 1.
Comparative example 1
The method for preparing polylactic acid according to example 1 was different in that the lactic acid-grafted cellulose nanocrystal prepared in step (1) was directly blended with polylactic acid in a banburying mixer without performing the operation of step (2).
Comparative example 2
The method for preparing polylactic acid according to example 1 was performed, except that the lactic acid-grafted cellulose nanocrystal prepared in step (1) was mixed with polyethylene glycol at room temperature according to mass ratio, and then the obtained product was blended with polylactic acid in banburying mixing through ethanol washing, deionized water washing, filtration and vacuum drying.
TABLE 1
| Crystallinity degree | Tensile Strength (MPa) | |
| Example 1 | 52.1％ | 45MPa |
| Example 2 | 49.4％ | 43MPa |
| Comparative example 1 | 38.3％ | 34MPa |
| Comparative example 2 | 42.3％ | 39MPa |
The test results of the above examples 1-2 and comparative examples 1-2 are shown in table 1, and it can be seen that the polylactic acid material prepared by the present invention has a crystallinity of up to 52.1%, and a tensile strength of up to 45MPa, and the crystallization property and mechanical property of polylactic acid are effectively improved by using excellent heterogeneous nucleation of bio-based cellulose nanocrystals and excellent processing fluidity of polyethylene glycol, in cooperation with the nucleating agent.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that the above-mentioned preferred embodiment should not be construed as limiting the invention, and the scope of the invention should be defined by the appended claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.
Claims (1)
1. The method for preparing the polylactic acid by utilizing the modified cellulose nanocrystalline is characterized by comprising the following steps of:
(1) Uniformly mixing cotton fiber crushed aggregates, 90wt% of lactic acid aqueous solution and 37wt% of concentrated hydrochloric acid, transferring into a polytetrafluoroethylene lining reaction kettle, reacting for 7 hours at 140 ℃ under a closed condition, washing a product with deionized water, centrifuging to obtain a supernatant, and freeze-drying to obtain lactic acid grafted cellulose nanocrystalline; wherein the cotton fiber particles: 90wt% aqueous lactic acid: the mass ratio of the 37% concentrated hydrochloric acid is 1:10:1, a step of;
(2) Ultrasonically dispersing the lactic acid grafted cellulose nanocrystalline obtained in the step (1) in N, N-dimethylformamide to form stable dispersion liquid, adding polyethylene glycol into the dispersion liquid, reacting for 2 days at 130 ℃ under continuous stirring, and washing the obtained product with ethanol, washing with deionized water, filtering and vacuum drying to obtain cellulose nanocrystalline grafted with lactic acid and polyethylene glycol together; wherein the mass ratio of the lactic acid grafted cellulose nanocrystalline to the polyethylene glycol is 100:4, a step of;
(3) Mixing the product prepared in the step (2) with polylactic acid according to a mass ratio of 2:100 is added into a banburying mixer, the temperature is controlled at 180 ℃, the rotating speed is 90rpm, the heat is preserved for 120min, then the temperature is reduced to 60 ℃ at the cooling rate of 15 ℃/min, the heat is preserved for 3h, and then the room temperature is reduced, thus obtaining the polylactic acid material.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007136086A1 (en) * | 2006-05-23 | 2007-11-29 | Kyushu University, National University Corporation | Material comprising polylactic acid and cellulose fiber |
| CN105780189A (en) * | 2016-03-28 | 2016-07-20 | 桂林理工大学 | Preparation method of sisal cellulose nano-whisker enhanced polylactic acid/poly(ethylene succinate) biological composite material |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007136086A1 (en) * | 2006-05-23 | 2007-11-29 | Kyushu University, National University Corporation | Material comprising polylactic acid and cellulose fiber |
| CN105780189A (en) * | 2016-03-28 | 2016-07-20 | 桂林理工大学 | Preparation method of sisal cellulose nano-whisker enhanced polylactic acid/poly(ethylene succinate) biological composite material |
Non-Patent Citations (2)
| Title |
|---|
| 华笋.纤维素接枝共聚物对聚乳酸结晶性能和拉伸流变性能的影响.高分子学报.2018,(第8期),第1136-1144页. * |
| 张春梅.接枝改性纤维素纳米晶增强聚乳酸.塑料工业.2017,第45卷(第12期),第45-48页. * |
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