Polyhydroxyl carboxylic acid modified material capable of completely biodegrading

Abstract

The present invention discloses one kind of biodegradable modified polyhydroxycarboxylic acid material, and features that the biodegradable modified polyhydroxycarboxylic acid material consists of polyhydroxycarboxylic acid and polyacid polyol, with the polyol being tribasic alcohol or higher alcohol or the mixture of dibasic alcohol and tribasic alcohol or higher alcohol. The polyacid polyol toughened biodegradable modified polyhydroxycarboxylic acid material has greatly raised toughness, simple and environment friendly preparation process, low cost and broadened application range.

Description

technical field [0001] The invention relates to a completely biodegradable polyhydroxycarboxylic acid modified material. technical background [0002] Traditional polymer materials play an irreplaceable role in the process of social and economic development, but they face two insurmountable problems of "white pollution" and "oil shortage". With the deterioration of the environment and the rapid increase of oil prices, people pay more and more attention to the development of environmentally friendly renewable materials. [0003] Among them, polyhydroxycarboxylic acid represented by polylactic acid (PLA) and polyhydroxybutyrate (PHB) is a very important class of renewable biodegradable materials. The monomer raw material is obtained, and then polyhydroxycarboxylic acid is obtained by polymerization of the monomer. This kind of material can be quickly degraded into non-toxic small molecules after being discarded in nature after application. More importantly, this kind of mate...

AI Technical Summary

Problems solved by technology

[0004] However, there are currently two major shortcomings in these materials, which restrict their application in actual life and production. Taking polylactic acid as an example, it often takes two steps to obtain high-molecular polyhydroxycarboxylic acid from lactic acid. ester, and then catalyzed ring-opening polymerization of lactide to obtain high molecular weight polyhydroxycarboxylic acid

This results in a high price of high molecular weight polyhydroxycarboxylic acid, which is not suitable for replacing conventional polymer materials

The cost of polyhydroxycarboxylic acid directly obtained by one-step method is low, but the toughness is too poor to be used in actual products

This contradiction greatly limits the current application of polyhydroxycarboxylic acid

[0005] The patent WO9204493 of Battelle Company of the United States mentions the use of small molecules or oligomers to plasticize and toughen polylactic acid. In the patent WO9407941 of Cargill Company, various commercial plasticizers are also used to reduce the glass transition temperature of polylactic acid. The patent of Neste Company of Finland US6117928 uses small molecule esters triethylglyceride and tributylglyceride to plasticize polylactic acid, but the toughness of plasticized polylactic acid has not been significantly improved, and polylactic acid has lost its transparency

[0006] Many companies use elastomers to toughen polylactic acid. Oxford University's patent WO9001521 mentions the use of natural rubber to toughen polylactic acid, while Japanese patents JP2002037987, JP2003183488, and JP2005029758 use ethylene-propylene rubber, natural rubber or isobutylene rubber, and epoxy-modified rubber respectively. Natural rubber toughened polylactic acid, the toughness of polylactic acid has been significantly improved, but this modification makes polylactic acid lose its complete biodegradability

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