PLA/Talc复合材料结晶动力学研究

Crystallization kinetics of PLA/Talc composites

采用密炼机熔融混炼制备了聚乳酸(PLA)基生物降解材料,并以滑石粉(Talc)作为成核剂,聚乙二醇(PEG)为增塑剂,研究了它们单独以及共同对PLA结晶能力的影响。使用DSC和热台偏光显微镜研究了PLA/Talc、PLA/PEG和PLA/PEG/Talc共混体系的等温结晶动力学,对所得数据用Avrami方程进行了处理,并计算了其活化能,结果表明:随着Talc的不断加入,加快了成核速率和球晶生长速率,缩短了半结晶时间并降低了活化能,表明Talc是有效的成核剂。而PEG的不断加入,提高了其结晶温度区间,并且球晶尺寸变得更大、更加完善,说明PEG是一个很好的增塑剂。

Polylactic acid(PLA)based biodegradable materials are prepared by melt mixing in an internal mixer.The effects of Talc as nucleating agent and PEG as plasticizer on the crystallization ability of PLA are studied.Isothermal crystallization kinetics of PLA/Talc,PLA/PEG and PLA/PEG/Talc blends are studied by DSC and polarizing microscope.The data are processed by Avrami equation and the activation energy is calculated.The results show that with the continuous addition of Talc,the nucleation rate and spherulite growth rate are accelerated,the semi-crystallization time is shortened and the activation energy is reduced,which indicates that Talc is an effective nucleating agent.The continuous addition of PEG improves the crystallization temperature range,and the spherulite size becomes larger and more perfect,indicating that PEG is a good plasticizer.