详细信息

不同分子量聚L-乳酸的非等温结晶动力学研究    

Non-isothermal Crystallization Kinetics of Poly(L-lactic acid) in Different Molecular Weight

文献类型:期刊文献

中文题名:不同分子量聚L-乳酸的非等温结晶动力学研究

英文题名:Non-isothermal Crystallization Kinetics of Poly(L-lactic acid) in Different Molecular Weight

作者:蒲文亮[1];唐颂超[1];张德震[1];侯文婷[1]

机构:[1]华东理工大学材料科学与工程学院,上海市先进聚合物材料重点实验室,上海200237

年份:2012

期号:6

起止页码:76

中文期刊名:高分子通报

外文期刊名:Polymer Bulletin

收录:CSTPCD;;北大核心:【北大核心2011】;CSCD:【CSCD2011_2012】;

基金:国家自然科学基金(5117304)

语种:中文

中文关键词:聚乳酸;非等温结晶;结晶动力学;结晶活化能

外文关键词:Polylactic acid; Non-isothermal Crystallization; Crystallization Kinetics; Crystallization activation energy

摘要:采用DSC方法研究了不同分子量聚乳酸在不同降温速率下的结晶过程,利用Ozawa方程和Kissinger方程研究了其非等温结晶动力学。结果表明,随着降温速率的增大和分子量增加,结晶峰向低温偏移,且峰形趋于平缓。求得分子量为2.6×104的聚乳酸的Ozawa指数m接近3,以异相成核的三维球晶生长为主,而分子量为14.3×104和19.2×104的聚乳酸的Ozawa指数m接近4,以均相成核的三维球晶生长为主,结晶活化能分别为-165.8kJ/mol、-82.1kJ/mol和-75.4kJ/mol。建立的"铰链"模型解释了不同分子量聚乳酸结晶活化能的显著差异,得到了聚乳酸分子量与结晶活化能的关系。
The different molecular weight Poly(Lqactic acid) (PLLA) was investigated by differential scanning calorimetry (DSC) under different cooling rates of the crystallization process. Ozawa and Kissinger equation were applied to study the non-isothermal crystallization kinetics of PLLA. The results showed that the crystalliazation peaks shift to low direction and peak width increased with increasing of the cooling rate and the molecular weight. The crystallization activation energy are - 165.8kJ/mol for the PLLA(M=2. 6 × 104 ) which Ozawa exponent m closing to 3 indicated the crystallization model is heterogeneous nucleation and three dimensional crystal growth, -82. 1lkJ/mol and -75.4kJ/mol for the PLLA(M= 14.3 × 104 and 19.2 × 104 ) which Ozawa exponent m closing to 4 indicated homogeneous nucleation and three-dimensional crystal growth, respectively. The " hinge" model explains the significant difference of the crystallization activation energy of different molecular weight PLLA, and giving the relation between the molecular weight and the crystallization activation of PLLA.

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