结晶度
水解
高分子化学
无定形固体
差示扫描量热法
扫描电子显微镜
凝胶渗透色谱法
材料科学
形态学(生物学)
化学工程
丙交酯
摩尔质量分布
化学
复合材料
聚合物
聚合
结晶学
有机化学
热力学
物理
工程类
生物
遗传学
作者
Hideto Tsuji,Yoshito Ikada
标识
DOI:10.1002/(sici)1099-0518(19980115)36:1<59::aid-pola9>3.0.co;2-x
摘要
Hydrolysis of poly(L-lactide) (PLLA) films in 0.01N NaOH at 37°C was investigated by gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, and polarizing optical microscopy. The change in molecular weight distribution and surface morphology of PLLA films during hydrolysis revealed that PLLA film hydrolysis in dilute alkaline solution proceeded mainly via the surface erosion mechanism. An insignificant dependence of the rate of weight loss per unit surface area on the PLLA film thickness also supported this conclusion. Etching of the outside of PLLA spherulites resulted in preferred hydrolysis of PLLA chains in the amorphous region. The disorientation of lamella and inhomogeneous erosion in the spherulites implied that hydrolysis of PLLA chains occurred predominantly in the amorphous region between the crystalline regions in the spherulites. The rate of weight loss per unit surface area decreased linearly with the increase in the initial crystallinity of PLLA film, while the radius of spherulites had practically no significant effect on the hydrolysis of PLLA film. The specific low molecular weight of PLLA chains produced by hydrolysis increased with the rise in annealing temperature of the PLLA film, suggesting that the PLLA chains released were the component of one fold in the crystalline region. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 59–66, 1998
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