文献类型：期刊文献

英文题名：The Nucleation Effect of Modified Carbon Black on Crystallization of Poly(lactic acid)

作者：Su, Zhizhong[1];Li, Qiuying[1];Liu, Yongjun[1];Guo, Weihong[1];Wu, Chifei[1]

机构：[1]E China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China

年份：2010

卷号：50

期号：8

起止页码：1658

外文期刊名：POLYMER ENGINEERING AND SCIENCE

收录：;EI(收录号：20103613213585);WOS:【SCI-EXPANDED(收录号:WOS:000280278300018)】；

基金：The authors are grateful for the financial supports of the Key Project of National Natural Science Foundation of China (No. 50733001).

语种：英文

外文关键词：Activation energy - Cracks - Differential scanning calorimetry - Lactic acid - Nucleation - Temperature distribution

摘要：The nonisothermal crystallization of poly(lactic acid) (PLA), PLA/carbon black (CB), and PLA/modified carbon black (MCB) composites were investigated using differential scanning calorimetry (DSC) analysis. The rate of crystallization and the spherulitic morphologies of the PLA and PLA/MCB composites during isothermal crystallization were investigated using DSC and observed by means of polarizing optical microscopy (POM), respectively. The results show that either CB or MCB acts as an efficient nucleating agent for PLA. The nucleation activities of CB and MCB were quantitatively determined. It is shown that MCB has higher nucleating activity than CB in PLA. An isoconversional method correlates the temperature dependence of the effective activation energy and was used to evaluate the effective activation energy of PLA and PLA/MCB composites. It is confirmed that MCB advances the nuclei density and promotes the crystallization rate of the PLA matrix significantly. In addition, an interesting phenomenon of the periodic cracks of PLA spherulites observed by using POM is reported. The unbalanced surface stresses arising from growth features and thermal shrinkage may be the two main factors accounting for the formation of target pattern cracks. POLYM. ENG. SCI., 50:1658-1666, 2010. (C) 2010 Society of Plastics Engineers