Polylactic acid injection molding method

A technology of injection molding and injection molding machine, which is applied in the direction of coating, etc., can solve the problems of polylactic acid's machinability decline, application blockage, color deepening, etc., and achieve the effect of improving hydrophilicity, high transparency, and improving mechanical properties

Pending Publication Date: 2021-10-01
无锡御束生物材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a polylactic acid injection molding method to solve the problem that although the polylactic acid prepared by the existing polylactic acid injection molding method has improved mechanical properties and toughness, it leads to a decline in the processability of polylactic acid , and the color deepens seriously, which hinders its application in some industries

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] A polylactic acid injection molding method, comprising the following steps:

[0044] Step 1, initial polycondensation of lactic acid:

[0045] Mix L-lactic acid and trimethyl orthoformate at a mass ratio of 10:0.25, stir at room temperature for 3 hours, and then complete the dehydration treatment. Add antimony chloride to the dehydrated lactic acid, mix well, and place at 45°C, Under the condition of 0.1Mpa, vacuum distillation was performed for 2 hours, and then dried and recrystallized from dichloromethane to obtain a preliminary polymer of polylactic acid; wherein, the mass ratio of lactic acid to antimonous chloride was 10:0.05.

[0046] Step 2, Preliminary Aggregate Depolymerization:

[0047] Treat the polylactic acid preliminary polymer at a temperature of 140°C and a pressure lower than 100Pa to obtain a polylactic acid prepolymer;

[0048] Step 3, ring opening and block polymerization:

[0049] At 30°C, under the action of initiator and N,N-dimethylethanolamine...

Embodiment 2

[0056] A polylactic acid injection molding method, comprising the following steps:

[0057] Step 1, initial polycondensation of lactic acid:

[0058] Mix D-lactic acid and trimethyl orthoformate at a mass ratio of 10:0.1, stir at room temperature for 5 hours, and then complete the dehydration treatment. Add antimony chloride to the dehydrated lactic acid, mix well, and heat at 40°C, Under the condition of 0.1Mpa, vacuum distillation was performed for 2 hours, and then dried and recrystallized from dichloromethane to obtain a preliminary polymer of polylactic acid; wherein, the mass ratio of lactic acid to antimonous chloride was 10:0.04.

[0059] Step 2, Preliminary Aggregate Depolymerization:

[0060] Treating the primary polylactic acid polymer at a temperature of 120°C and a pressure lower than 100Pa to obtain a polylactic acid prepolymer;

[0061] Step 3, ring opening and block polymerization:

[0062] At 25°C, under the action of initiator and N,N-dimethylethanolamine,...

Embodiment 3

[0069] A polylactic acid injection molding method, comprising the following steps:

[0070] Step 1, initial polycondensation of lactic acid:

[0071] Mix DL-lactic acid and trimethyl orthoformate at a mass ratio of 10:0.4, stir at room temperature for 5 hours, and then complete the dehydration treatment. Add antimony chloride to the dehydrated lactic acid, mix well, and place at 50°C, Under the condition of 0.1Mpa, vacuum distillation was performed for 2 hours, and then dried and recrystallized from dichloromethane to obtain a preliminary polymer of polylactic acid; wherein, the mass ratio of lactic acid to antimonous chloride was 10:0.06.

[0072] Step 2, Preliminary Aggregate Depolymerization:

[0073] Treat the polylactic acid preliminary polymer at a temperature of 160°C and a pressure lower than 100Pa to obtain a polylactic acid prepolymer;

[0074] Step 3, ring opening and block polymerization:

[0075] At 45°C, under the action of initiator and N, N-dimethylethanolam...

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Abstract

The invention relates to a polylactic acid injection molding method which comprises the following steps: step 1, preliminary polycondensation of lactic acid: dehydrating lactic acid, and then performing polycondensation under the catalytic action of a first catalyst to obtain a preliminary polylactic acid polymer; step 2, primary polymer depolymerization: carrying out depolymerization treatment on the polylactic acid primary polymer to obtain a polylactic acid prepolymer; step 3, ring opening and block polymerization: carrying out ring opening on the polylactic acid prepolymer, and polymerizing the polylactic acid prepolymer with dimethyl diallyl ammonium chloride to obtain a polylactic acid block copolymer; and step 4, injection molding: adding the polylactic acid block copolymer into an injection molding machine for injection molding. The problems existing in an existing polylactic acid injection molding method are solved, namely, the prepared polylactic acid is improved in the aspects of mechanical property and toughness, the processability and transparency of the polylactic acid can be guaranteed, and the polylactic acid can be applied to most industries.

Description

technical field [0001] The invention relates to the field of polyurethane elastomers, in particular to a polylactic acid injection molding method. Background technique [0002] Polylactic acid is a polymer made of lactic acid as the main raw material. It can be synthesized through renewable plant resources-corn starch, tapioca starch, plant fiber, biological sugar, etc. The synthesis energy consumption is low, no pollution, and is conducive to ecology recycling; polylactic acid has good biodegradability, will not release toxic gases such as nitrogen and sulfide after incineration, and can be completely degraded by microorganisms in nature after landfilling, eventually producing carbon dioxide and water, without polluting the environment; Lactic acid has good processing properties and mechanical properties, which are comparable to general-purpose plastics polystyrene and polyethylene terephthalate, and is expected to become a substitute for petroleum-based general-purpose pla...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F293/00C08F226/02C08G63/08B29C45/00
CPCC08F293/00C08F226/02C08G63/08B29C45/0001
Inventor 王辉王庆
Owner 无锡御束生物材料科技有限公司
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