Method for preparing polylactic acid-based high-elasticity copolymer

A technology of polylactic acid-based copolymers, which is applied in the field of preparation of polylactic acid-based high-elastic copolymers, can solve the problems of destroying the equimolar ratio of hydroxyl and carboxyl groups, the molecular weight of the product is not high, and the number of hydroxyl groups is increased, so as to increase efficiency, Simplify the refining process and improve toughness

Active Publication Date: 2010-12-01
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, because the addition of polyethylene glycol increases the number of hydroxyl groups during the esterification reaction and destroys the equimolar ratio of hydroxyl and carboxyl groups, the molecular weight of the product prepared in this way is not high and cannot be used for general-purpose plastics.

Method used

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  • Method for preparing polylactic acid-based high-elasticity copolymer
  • Method for preparing polylactic acid-based high-elasticity copolymer
  • Method for preparing polylactic acid-based high-elasticity copolymer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] (1) Add 800g of L-lactic acid into the vacuum reactor, add 0.5g of stannous chloride catalyst, vacuumize, control the pressure of the reactor at 1.0Kpa, raise the temperature of the reactor to 100°C, and react for 5 hours; then the temperature of the reactor Raise to 165°C, drop the pressure below 100Pa, and continue the reaction for 10 hours to obtain polylactic acid.

[0035] (2) Add 80 g of polytetrahydrofuran glycol (PTMEG) to a vacuum reactor containing polylactic acid, the pressure of the reactor is 1.0 Kpa, the temperature of the reactor is 150° C., and react for 6 hours to obtain a copolymer prepolymer.

[0036] (3) The prepolymer obtained by the reaction in step (2) is mixed with 1,6-hexamethylene diisocyanate (HDI), 1,4-butanediol according to the -NCO of isocyanate: -OH of the copolymer prepolymer: extended -OH (molar ratio) of the chain agent = 1.09: 1.00: 0.05 is added to the reactor, the amount of polyol is 5wt% of the amount of isocyanate, at 140 ° C, rea...

Embodiment 2

[0039] (1) Put 800g of L-lactic acid into the vacuum reactor, add catalyst 0.5g stannous octoate, vacuumize, control the pressure of the reactor at 1.0Kpa, raise the temperature of the reactor to 100°C, and react for 5 hours; then the temperature of the reactor rises To 165°C, the pressure drops below 100Pa, and the reaction is continued for 10 hours to obtain polylactic acid.

[0040] (2) Add 80g of polycaprolactone diol (PCL) to the vacuum reactor containing polylactic acid, the reactor pressure is 1.0Kpa, the reactor temperature is 150°C, react for 6 hours to obtain the copolymer prepolymer .

[0041](3) The prepolymer obtained by the reaction in step (2) is prepolymerized with diphenylmethane-4,4'-diisocyanate (MDI), 1,4-butanediol, and isocyanate-NCO: copolymer The -OH of the body: the -OH of the chain extender (molar ratio) = 1.05: 1.00: 0.03 is added to the reactor, the amount of polyol is 5wt% of the amount of isocyanate, at 140 ° C, reacted for 15 minutes, and releas...

Embodiment 3

[0044] (1) Add 500g of D-lactic acid and 300g of L-lactic acid into the vacuum reactor, add catalyst 0.5g tetrabutyl titanate, vacuumize, control the pressure of the reactor at 2.0Kpa, raise the temperature of the reactor to 120°C, and react 5 hours; then the temperature of the reactor was raised to 180° C., the pressure dropped below 100 Pa, and the reaction was continued for 8 hours to obtain polylactic acid.

[0045] (2) Add 160g of polyethylene adipate diol (PEA) to a vacuum reactor containing polylactic acid, the pressure of the reactor is 1.0Kpa, the temperature of the reactor is 200°C, and the reaction is carried out for 5 hours to obtain a copolymerized prepolymers.

[0046] (3) react the prepolymer obtained in the step (2) with toluene diisocyanate (TDI), trimethylolpropane according to the -NCO of isocyanate: the -OH of the copolymer prepolymer: the -OH of the chain extender ( Molar ratio) = 1.05: 0.99: 0.05 into the reactor, the amount of polyol is 7wt% of the amou...

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Abstract

The invention belongs to the field of high molecular materials, in particular relates to a method for preparing a polylactic acid-based high-elasticity copolymer, which comprises the following specific steps of: the preparation of a polylactic acid matrix; the preparation of a copolymer prepolymer; and chain extension reaction of the copolymer prepolymer. In the method, due to the adoption of abundant and readily available lactic acid, polymer polyols, isocyanate, polyalcohol and polyamine, the complex refining process during the use of lactide is simplified, and the industrial production is convenient; a flexible chain segment of the polymer polyols is introduced into a molecular chain of polylactic acid, the ductility of the polylactic acid is improved, and the application field of materials is expanded; end groups of the synthesized prepolymer are hydroxyl, and diisocyanate and the polyalcohol (the polyamine) are subjected to chain extension to improve the efficiency of the chain extension greatly; and the polyalcohol or the polyamine is added into a system, so the polymer after the chain extension forms a micro-crosslinked structure easily, and the heat resisting property of the polylactic acid-based copolymer is improved greatly.

Description

technical field [0001] The invention belongs to the field of polymer materials, and in particular relates to a preparation method of a polylactic acid-based high elastic copolymer. Background technique [0002] As a biodegradable polymer material, polylactic acid has been extensively studied due to its biodegradable and renewable biofriendly properties. However, due to the slow crystallization rate and strong molecular chain rigidity of polylactic acid itself, the material has poor toughness, and it can only be used as a packaging material, which limits its wide application. Generally, the impact performance can be improved by plasticizing, chemical blending modification, and physical blending modification. But at the same time of modification, the tensile properties decreased drastically. In recent years, there are many methods for studying blend toughening, and a large number of toughening models have emerged. [0003] For the application of various polymer materials, t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G18/66C08G18/42C08G63/06C08G81/00
Inventor 任杰冯舒勤陈大凯张乃文
Owner TONGJI UNIV
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