Structural changes and crystallization kinetics of polylactide under CO2 investigated using high-pressure Fourier transform infrared spectroscopy

被引：34

作者：

Li, Shaojie ^{[1
]}

He, Ting ^{[1
]}

Liao, Xia ^{[1
]}

Yang, Qi ^{[1
]}

Li, Guangxian ^{[1
]}

机构：

[1] Sichuan Univ, Coll Polymer Sci & Engn, State Key Lab Polymer Mat Engn, Chengdu 610065, Sichuan, Peoples R China

来源：

POLYMER INTERNATIONAL | 2015年 / 64卷 / 12期

基金：

中国国家自然科学基金;

关键词：

polylactide; in situ; FTIR; CO2; crystallization; SUPERCRITICAL CO2-ASSISTED SYNTHESIS; CARBON-DIOXIDE; THERMAL-BEHAVIOR; SEMICRYSTALLINE STATES; POLY(L-LACTIC ACID); POLY(LACTIC ACID); DISSOLVED CO2; POLYMERS; MORPHOLOGY; FOAMS;

D O I：

10.1002/pi.4977

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The structural changes and crystallization kinetics of polylactide (PLA) during cold crystallization under CO2 at 80 degrees C were studied using in situ high-pressure Fourier transform infrared (FTIR) spectroscopy. The FTIR spectra show that PLA can crystallize under air and CO2, and some differences are observed. In the second-derivative spectra, the 1220cm(-1) band is only found for PLA crystallized under CO2, and the tt conformer of PLA crystallized under CO2 is located at 1749cm(-1), while that of PLA crystallized under air is located at 1751cm(-1). From wide-angle X-ray diffraction, only the -crystal is observed when PLA is crystallized under air, whereas the -crystal appears when crystallized under CO2. The crystalline-sensitive bands at 921 and 1458cm(-1) were used to analyze the crystallization kinetics of PLA. When PLA crystallizes under air, the 1458cm(-1) band changes faster than the 921cm(-1) one; when it crystallizes under CO2, the result reverses. This suggests that CO2 hinders interchain interactions while promoting the helix conformation. (c) 2015 Society of Chemical Industry

引用

页码：1762 / 1769

页数：8