端羟基聚(乳酸-己内酯)共聚物的合成及表征

Synthesis and Characterization of Hydroxyl-terminated Poly(lacticacid-co-ε-caprolactone)

以乳酸(D,L-LA)和ε-己内酯(-εCL)为原料,采用梯度升温法,通过直接熔融缩聚合成了系列端羟基聚(乳酸-己内酯)共聚物(PLCA)。最佳工艺条件为:压力0.098MPa,催化剂Sn(Oct)2用量0.8%(质量分数),n(D,L-LA)∶n(-εCL)=8∶2,聚合温度170℃,反应7h。用特性粘度、FT-IR1、H-NMR、XRD、DSC等对其进行表征,结果表明,系列PLCA中的粘均分子量最大可达20785,Tg均比PLA的小,且随-εCL含量的增加,Tg越小,有效改善了PLA的脆性。结晶度比PLA有所降低,说明-εCL的加入使柔韧性增强。

The hydroxyl-terminated modified poly（lactic acid-co-ε-caprolactone） copolymers（PLCA） were syn thesized via directly melt polycondensation with lactic acid（D, L-LA） and ε-caprolactone（ε-CL） as raw material using linear heating method. The best synthesis conditions were pressure 0. 098 MPa, catalyst dosage 0. 8% （mass frac tion）, n（D, L-LA） ： n（ε-CL）=8 ： 2, polymerization temperature of 170℃ and polymerization time 7h. The copoly- mers were characterized by viscosity-average molecular weight, FT-IR, ^1H-NMR, DSC, TGA and XRD. The results demonstrate that the biggest viscosity average molecular weight of PLCA is 20785, Tg of PLCA is lower than PLA, and with the ε-CL content increased, the Tg is smaller, which improved the brittleness of PLA effectively, the crystallinity of PLCA is lower than PLA, it indicates that the flexibility increases because of the addition of ε-CL.