文献类型：期刊文献

英文题名：Foaming of Poly(lactic acid) Based on Its Nonisothermal Crystallization Behavior under Compressed Carbon Dioxide

作者：Li, Da-chao[1];Liu, Tao[1];Zhao, Ling[1];Lian, Xiao-song[1];Yuan, Wei-kang[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2011

卷号：50

期号：4

起止页码：1997

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20110713667575);WOS:【SCI-EXPANDED(收录号:WOS:000287049700025)】；

基金：The authors are grateful to the National Natural Science Foundation of China (Grant Nos. 50703011, 20976045, and 20976046), Shanghai Shuguang Project (08SG28), Program for New Century Excellent Talents in University (NCET-09-0348), Program for Changjiang Scholars, Innovative Research Team in University, the 111 Project (B08021), and the support of "the Fundamental Research Funds for the Central Universities",

语种：英文

外文关键词：Differential scanning calorimetry - Temperature - Lactic acid - Crystallization

摘要：The nonisothermal crystallization behaviors of poly(lactic acid) (PLA) under ambient N-2 and compressed CO2 (5-50 bar) at cooling rates of 0.2-2.0 degrees C/min were carefully studied using high-pressure differential scanning calorimetry. The presence of compressed CO2 postponed. the crystallization peak to a lower temperature region while effectively reducing the half crystallization time and enhancing the crystallinity of the PLA specimen. On the basis of these findings, a new foaming strategy was proposed and utilized to fabricate PLA foams using the ordinary unmodified PIA. The upper and lower temperature limits of this foaming strategy, were 105 and 90 degrees C, which were determined by the melt strength and crystallization behavior of the unmodified PLA specimen, respectively. In this temperature range, PLA foams with interconnected structures, porosity of 67.9-91.4%, and expansion ratio of 15-30 times are controllably produced. The obtained PLA foams have widely distributed average bubble size of 80-270 mu m and CO2 enhanced crystallinity of 32-38%.