马来酸酐接枝HDPE/SEBS非等温结晶动力学

用DSC方法研究了HDPE、HDPE/SEBS、HDPE/SEBS-g-MAH的非等温结晶动力学。莫志深方法和DSC曲线分析说明HDPE中添加非结晶的热塑性弹性体SEBS后,HDPE的结晶焓变小,结晶速率变慢;当HDPE/SEBS聚合物链接上马来酸酐后,由于分子链之间极性基团的相互作用和分子链的支化更加阻碍了分子链的规则排列和影响链段在结晶扩散迁移规整排列的速度,使得结晶焓降低的幅度最大、结晶速率最小。Kissinger法分析结果得出SEBS的加入使HDPE结晶变得困难,活化能升高,但当HDPE/SEBS链接上MAH后结晶活化能变得最小。

Nonisothermal Crystallization Kinetics of HDPE/SEBS-g-MAH

The isothermal crystallization kinetics of HDPE,HDPE/SEBS and HDPE/SEBS-g-MAH at different cooling rates have been investigated by differential scanning calorimetry(DSC).The methods of Mo Zhi-shen and Kissinger for isothermal crystallization kinetics were used to analyze the crystallization characteristics of HDPE,HDPE/SEBS and HDPE/SEBS-g-MAH.The results demonstrate that the crystallization rate of HDPE is highest and that of SEBS/HDPE is higher than that of HDPE/SEBS-g-MAH with the aid of Mo Zhi-shen method and DSC curves.The enthalpy of HDPE is decreased with adding SEBS due to partial destruction of crystal region and the enthalpy of HDPE/SEBS-g-MAH is lowest owing to stronger effect among polar branch groups.According to the analysis of Kissinger method,the crystallization activation energy of HDPE,HDPE/SEBS and HDPE/SEBS-g-MAH is 446.50 kJ/mol,476.03 kJ/mol and 407.85 kJ/mol,respectively.