Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation of high molecular weight high performance polylactic acid

A high-molecular-weight, polylactic acid technology is applied in the field of preparation of high-molecular-weight polylactic acid to achieve the effects of improving product toughness, easy control of reaction conditions, and simple equipment

Active Publication Date: 2011-11-23
CHANGZHOU INST OF ENERGY STORAGE MATERIALS &DEVICES
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to synthesize high-molecular-weight PLA, improve the toughness, hydrolysis resistance, thermal stability and durability of PLA, and overcome the fear of water in the storage of small molecule isocyanate chain extenders, Can not be fully mixed in advance, volatilization endangers the health of personnel and short storage time and other problems, the purpose of the present invention is to provide a preparation method of high molecular weight PLA

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation of high molecular weight high performance polylactic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Add 500 g of D,L-lactic acid with a purity of 87% into a 1000 mL three-necked bottle equipped with a mechanical stirrer, and dehydrate at 110° C. for 1.5 h under an air pressure of 0.1 MPa. Add 3 g of antimony trioxide catalyst, stir well, replace the air in the three-necked bottle with nitrogen repeatedly, and react at 135°C for 10 h under the air pressure of 500 Pa. After purification, 310 g of PLA prepolymer with a weight average molecular weight of 38230 is obtained.

Embodiment 2

[0031] Add 2Kg of D,L-lactic acid with a purity of 87% into a 5L batch reactor equipped with a mechanical stirrer, and dehydrate at 100°C for 2h under an air pressure of 0.1MPa. Add 8g of antimony trioxide catalyst, stir well, replace the air in the kettle repeatedly with nitrogen, react at 140°C for 8h under the pressure of 1000Pa, and obtain 1.26Kg of prepolymer with a weight average molecular weight of 20050 after purification.

Embodiment 3

[0033] Add 9.6 g of toluene diisocyanate and 500 g of polyethylene glycol with a molecular weight of 20,000 into a 1000 mL three-necked bottle equipped with a mechanical stirrer, and react at 70° C. for 2.5 h under nitrogen protection. Add 2.7 g of methyl ethyl ketone oxime, and react at 85° C. for 3.5 h under the protection of nitrogen to obtain the prepared isocyanate prepolymer, which is milky white light yellow solid.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for preparing poly lactic acid with high molecular weight. In the invention, bifunctional isocyanate, poly diol and isocyanate sealant are chosen to prepare an enclosed type isocyanate prepolymer and also used for the condensation polymerization reaction of a PLA prepolymer for extruding the chain extension, thereby realizing the preparation of the PLA with high molecular weight and high performance by one-step reaction. For the chain extension PLA of the enclosed type isocyanate prepolymer, the flexible polyether is introduced into the PLA, which obviously improves the toughness, the hydrolyzing resistance, the thermal stability and the endurance of products; moreover, the enclosed type isocyanate prepolymer chain extender can also overcome the problems that the small molecule isocyanate chain extender fears of water while being stored and can not be pre-mixed with materials, and the volatilization of the small molecule isocyanate chain extender harms the health of a tester and the storage time of the small molecule isocyanate chain extender is short; by utilizing the enclosed type isocyanate prepolymer reaction to extrude the chain extension PLA prepolymer, the method has the advantages of simple equipment, short reaction time, easily controlled reaction condition and easy realization of large-scale and continuous production.

Description

technical field [0001] The invention belongs to a preparation method of high molecular weight polylactic acid. Background technique [0002] There are two main ways to synthesize polylactic acid (PLA) from lactic acid: direct polycondensation and ring-opening polymerization. Direct polycondensation is a method for preparing PLA by dehydration condensation polymerization between lactic acid or its oligomer molecules. The method has simple process and low cost. However, due to the complex balance of free lactic acid, water, polyester and by-product lactide in the reaction system, it is difficult to prepare high molecular weight polymers. To obtain high-molecular-weight polymers, the key is to remove free water and reaction-generated water from the reaction system in time, and to suppress the rate of formation of by-product lactide. This method has certain defects, such as: high requirements on reaction conditions, long reaction time, poor product performance and yellowing,...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C08G63/78C08G63/685C08G63/66
Inventor 栾世方殷敬华朱连超
Owner CHANGZHOU INST OF ENERGY STORAGE MATERIALS &DEVICES
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com