聚丙烯接枝马来酸酐及其离聚物的等温结晶行为

THE ISOTHERMAL CRYSTALLIZATION BEHAVIOR OF MALEIC ANHYDRIDE GRAFT POLYPROPYLENE AND ITS IONOMERS

采用ＤＳＣ对马来酸酐接枝聚丙烯（ＰＰｇＭＡＨ）及其３种５个离聚物的等温结晶行为进行了研究，发现在相对结晶度２％～９０％的范围内符合Ａｖｒａｍｉ方程．马来酸酐的引入及离子化并不改变ＰＰ的结晶行为，但样品的结晶速率增大，同时结晶速率亦随中和度的提高而增大．从Ｈｏｆｍａｎ理论得到７个样品的垂直于晶核的界面自由能σｅ，其变化与Ａｖｒａｍｉ方程的结果是一致的．

The kinetics of isothermal crystallization has been studied for Na +,Mn 2+ and Ca 2+ ionomers based on maleic anhydride graft polypropylene(PP g MAH) by DSC,compared with pure PP and PP g MAH.Avrami equation was valid for analyzing the experimental data.The fact that Avrami exponents close to three for all the samples implied the mode of PP crystallization was not changed by the solid graft modification.The introduction of ions increased the crystallization rate(characterized by the reciprocal of the half life of the crystallization, t -1 1/2 ) dramatically.At the same time,the increase of neutralization also increased the crystallization rate. The reducing of the interfacial free energies of the side surfaces of the nucle σ e,calculated from Hoffman theory,by the anhydride group and ions had the same trend with the results of Avrami equation.