文献类型：期刊文献

英文题名：Fully Biodegradable Long-Chain Branched Polylactic Acid with High Crystallization Performance and Heat Resistance

作者：Li, Chenyang[1];Gong, Weiguang[2];Deng, Zhaopeng[1];Yao, Zhongyang[1];Meng, Xin[1];Xin, Zhong[1]

机构：[1]East China Univ Sci & Technol, Dept Prod Engn, Shanghai Key Lab Multiphase Mat Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Res & Dev Ctr Sports Mat, Shanghai 200237, Peoples R China

年份：2022

卷号：61

期号：30

起止页码：10945

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20223312565388);WOS:【SCI-EXPANDED(收录号:WOS:000834342600001)】；

基金：? ACKNOWLEDGMENTS This work was financially supported by the Ningbo Public Welfare Science and Technology Projects 2021S09. The authors thank Dr. Peng Li for help with data analysis.

语种：英文

外文关键词：Crystallinity - Degradation - Heat resistance - Oxidation - Peroxides - Polyesters - Polymer blends - Specific heat

摘要：A biobased modifier, epoxidized cardanol, was used as a multifunctional coagent to develop long-chain branched polylactic acid (LCB-PLA) together with peroxide by a one-step reaction. The molecular structure of LCB-PLA was evaluated from weight-average molecular weight, intrinsic viscosity, and shear rheology. The results showed that the branching degree of LCB-PLA was enhanced with the increased addition amount of epoxidized cardanol due to the unique structure consisting of an epoxy group and a long carbon chain with multiple unsaturated bonds. The generated LCB-PLA exhibited improved crystallization performance and significant heat resistance. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) analyses showed that the long-chain branched structure could play the role of a nucleation site, resulting in the improved crystallization performance of PLA. Especially, for 0.3 wt % peroxide-modified PLA with 0.8 wt % epoxidized cardanol (PLA/0.3T/0.8E), the crystallinity of LCB-PLA reached approximately 44%, increasing the Vicat softening temperature (VST) and heat deflection temperature (HDT) to 156.2 and 82.5 degrees C, respectively, after a simple annealing treatment. Moreover, the annealed LCB-PLA exhibited better hydrolysis resistance than linear PLA in the early degradation stage, while it degraded rapidly in the later stage. In short, this work provided a green route to obtain LCB-PLA, which exhibited excellent crystallization properties and heat resistance.