High-crystallinity heat-resistant polylactic acid preparation method and apparatus

A technology with high crystallinity and preparation equipment, which is applied in the field of polylactic acid preparation, can solve the problems of limiting the application of polylactic acid, long molding time, and harsh conditions, so as to reduce the possibility of contamination, increase the speed of preparation, and increase the reaction rate Effect

Pending Publication Date: 2019-12-31
BENGBU COLLEGE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The direct polycondensation of lactic acid can only obtain polylactic acid with lower molecular weight, and the reaction conditions must be strictly controlled; the ring-opening polymerization of lactide requires high temperature and high vacuum, and the conditions are relatively harsh. The crystallinity of lactic acid is low and the temperature resistance of the...

Method used

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  • High-crystallinity heat-resistant polylactic acid preparation method and apparatus
  • High-crystallinity heat-resistant polylactic acid preparation method and apparatus
  • High-crystallinity heat-resistant polylactic acid preparation method and apparatus

Examples

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Embodiment 1

[0041] A method for preparing heat-resistant polylactic acid with high crystallinity, comprising the following steps:

[0042] Step 1: Add 100ml of dichloromethane to 15g of D-lactide in the spherical bottle body 1 to form a D-lactide solution with a molar concentration of 0.7mol / L, according to the molar ratio of D-lactide and initiator The initiator is added at a ratio of 12:1, wherein the initiator is any one of aluminum isopropoxide, potassium tert-butoxide, polyethylene glycol monomethyl ether or dipentaerythritol.

[0043] Then add the catalyst, the molar ratio of the catalyst to the initiator is 0.1:1, and the vacuum degree is 40-80 Pa under the reduced pressure state, and the microwave irradiation with a power of 200 watts makes it undergo ring-opening polymerization reaction, and the catalyst includes Catalyst I , Catalyst Ⅱ, catalyst Ⅰ is stannous octoate, stannous acetate, Sn(Oct) 2 、Sn(OBu) 2 、Fe(OEt) 3 Any one or more of them; Catalyst II is a titanium-tin comp...

Embodiment 2

[0056] A method for preparing heat-resistant polylactic acid with high crystallinity, comprising the following steps:

[0057] Step 1: Add 69.4ml of dichloromethane to 10gL-lactide to form an L-lactide solution with a molar concentration of 1mol / L, according to the molar ratio of L-lactide and initiator as 100:1 The initiator is added in proportion, wherein the initiator is any one of aluminum isopropoxide, potassium tert-butoxide, polyethylene glycol monomethyl ether or dipentaerythritol.

[0058] Then choose argon or nitrogen as the protective gas, and under the condition that the pressure of argon or nitrogen is 100-101325 Pa, add the catalyst, the molar ratio of the catalyst and the initiator is 0.25:1, and the power is 800 watts of microwave irradiation. It occurs ring-opening polymerization reaction, the catalyst includes catalyst I, catalyst II, and catalyst I is stannous octoate, stannous acetate, Sn(Oct) 2 、Sn(OBu) 2 、Fe(OEt) 3 Any one or more of them; Catalyst II ...

Embodiment 3

[0066] A method for preparing heat-resistant polylactic acid with high crystallinity, comprising the following steps:

[0067] Step 1: Add 100ml of dichloromethane to 15gL-lactide to form an L-lactide solution with a molar concentration of 0.7mol / L. According to the molar ratio of L-lactide and initiator, it is 6:1 The initiator is added in proportion, wherein the initiator is any one of aluminum isopropoxide, potassium tert-butoxide, polyethylene glycol monomethyl ether or dipentaerythritol.

[0068] Then place it under a reduced pressure state of 60 Pa Pa or under the protection of an inert gas, add a catalyst, the molar ratio of the catalyst to the initiator is 0.15:1, and microwave irradiation with a power of 600 watts makes it undergo ring-opening polymerization. Said catalyst includes catalyst I and catalyst II, and catalyst I is stannous octoate, stannous acetate, Sn(Oct) 2 、Sn(OBu) 2 、Fe(OEt) 3 Any one or more of them; Catalyst II is a titanium-tin composite catalys...

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Abstract

The invention discloses a high-crystallinity heat-resistant polylactic acid preparation method and apparatus. The high-crystallinity heat-resistant polylactic acid preparation method comprises the following steps: step 1: adding dichloromethane to lactide to prepare a lactide solution, adding an initiator, and then carrying out a ring-opening polymerization reaction by using microwave irradiationunder reduced pressure conditions; step 2: adding benzoic acid to terminate the reaction to obtain a product A; step 3: dissolving the product A with dichloromethane, performing re-precipitating withmethanol, and filtering out a white solid to obtain a product B; step 4: performing melt extrusion on L-polylactic acid, D-polylactic acid, talc, and polymethacrylate according to a certain ratio by atwin-screw extruder to obtain a nucleating agent; and step 5: performing melt blending on the nucleating agent and the product B in proportion to obtain a polylactic acid compound. The beneficial effects are as follows: heat resistance is improved, thermal stability is improved, and mechanical properties are improved by adding talc and polymethacrylate.

Description

technical field [0001] The invention relates to the field of polylactic acid preparation, in particular to a method and device for preparing heat-resistant polylactic acid with high crystallinity. Background technique [0002] Polylactic acid is a bio-based and degradable polymer material with excellent physical and mechanical properties, biodegradability and biocompatibility, and is widely used in agriculture, packaging materials, daily life, clothing and biomedical materials. Good application prospects. [0003] At present, the main methods of synthesizing polylactic acid are direct polycondensation of lactic acid and ring-opening polymerization of lactide. The direct polycondensation of lactic acid can only obtain polylactic acid with lower molecular weight, and the reaction conditions must be strictly controlled; the ring-opening polymerization of lactide requires high temperature and high vacuum, and the conditions are relatively harsh. The crystallinity of lactic aci...

Claims

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Application Information

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IPC IPC(8): C08L67/04C08L33/10C08K3/34C08G63/08C08G63/78C08G63/85C08G63/82
CPCC08L67/04C08G63/08C08G63/785C08G63/823C08L2205/025C08L2205/035C08L2205/24C08L33/10C08K3/34
Inventor 吴景梅邰燕芳朱俊杰
Owner BENGBU COLLEGE
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