Polylactic acid copolymer with high glass-transition temperature and preparation method thereof

Abstract

The invention discloses a polylactic acid copolymer with high glass-transition temperature and a preparation method thereof. Lactide and copolymerization monomer as main raw materials are subjected to ring opening polymerization and polycondensation reactions in the presence of a catalyst, so as to prepare the polylactic acid copolymer. The copolymer contains an aromatic diacid monomer unit and a diol monomer unit with ring structure, has weight average molecular weight of 3-300000 and the glass-transition temperature of 110-200 DEG C. The preparation method of the invention is simple, the raw material is lactide rather than a lactic acid solution, and the aromatic dicarboxylic acid rather than non phosgene or oxalic acid is used. By adjusting the ratio of materials for ring opening polymerization, can be simple, polylactic acid copolymers with different monomer unit ratio can be precisely designed, and the prepared polylactic acid copolymer has high molecular weight and glass transition temperature up to 200 DEG C.

Description

technical field [0001] The invention belongs to the field of biodegradable polymer materials, in particular to a polylactic acid copolymer with a high glass transition temperature and a preparation method thereof. Background technique [0002] Polylactic acid is a high molecular polymer prepared from lactic acid obtained by starch fermentation as the main raw material. Due to its good biocompatibility, degradation performance and non-toxic and non-irritating to the human body, it can replace traditional materials and is widely used in medical treatment. , pharmacy, agriculture, packaging industry, clothing industry and other fields, and my country's polylactic acid production raw material - corn is abundant, and the polylactic acid industry has broad prospects. [0003] As a crystallizable material, polylactic acid has replaced traditional general-purpose plastics in many aspects, but its glass transition temperature is below 60 °C, which limits the wider application of polyl...

AI Technical Summary

Problems solved by technology

Application No. 200580024916.X discloses a high molecular weight polylactic acid copolymer with excellent heat resistance, but its raw material phosgene is highly toxic; application No. 201110385357.2 discloses a polylactic acid copolymer and a preparation method thereof. Methods The polylactic acid copolymer prepared with lactic acid monomer and comonomer as the main raw material has high molecular weight, but the lactic acid monomer used is aqueous lactic acid aqueous solution, and the dehydration reaction needs to be increased for 0.5-3h before the polymerization reaction, which is time-consuming , energy consumption and glass transition temperature is not high