TBCL对PLA及LA/CL共聚物预聚体的扩链反应

CHAIN-EXTENTION OF POLYLACTIC ACID AND LA/CL COPOLYMER WITH TEREPHTHALOYLBISCAPROLACTAMATE

以乳酸或乳酸及ε-己内酯,与二元醇如丁二醇或一缩二乙二醇在催化剂的存在下缩聚,合成端羟基聚乳酸预聚体(HO-PLA-OH)或乳酸-ε-己内酯共聚物预聚体(HO-P(LA/CP)-OH)。以对苯二甲酰双己内酰胺(TBCL)为扩链剂,研究了扩链温度、预聚体结构、扩链剂/预聚体配比、扩链时间等对扩链反应的影响。结果表明,在扩链温度为150℃,酸值为0.9、黏均分子量为1120的(HO-P(LA/CP)-OH)预聚体,在扩链剂/预聚体的摩尔比为1.2时,经2 h扩链反应后,黏均分子量达到8630。并采用凝胶渗透色谱法对扩链前后聚合物的分子量变化进行了表征。

Hydroxy-terminated polylactic acid （HO-PLA-OH）or lactic acid-ε-caprolactone copolymers （HO-P（LA/CP）-OH） with viscosity-average molecular weight （-↑Mη） from 1120 to 1970 were synthesized by condensation polymerization from D,L-lactic acid, diethylene glycol or 1,4-butanediol with or without ε-caproiactone under the catalysis of Bu2SnO. The chain-extending reaction of HO-PLA-OH or HO-P（LA/CP）-OH with terephthaloyl- biscaprolactamate （TBCL） was studied. At the optimal reaction temperature 150℃ and the molar ratio of TBCL to HO-P（LA/CP）-OH at 1.2, chain-exte＇nding reaction of HO-P（LA/CP）-OH with acid value 0.9 and -↑Mη 1120 was carried out, and the chain-extended polymer with -↑Mη of 8630 was obtained. The HO-P（LA/CP）-OH prepolymer and the chain-extended polymer were also characterized by gel permeation chromatography （GPC） method.