交联低密度聚乙烯交联程度表征方法的研究

硅烷交联法和过氧化物交联法是聚乙烯交联改性的两种重要方法［１］，以往的文献上通常都以凝胶含量来表征这两种方法制备的交联产物的交联程度［２～６］，但是在实践中我们发现，凝胶含量基本相同的硅烷交联聚乙烯和过氧化物交联聚乙烯的性能存在着很大的差异，例如在７０℃的二甲苯中凝胶含量为６２％的过氧化物交联低密度聚乙烯（ＬＤＰＥ）的平衡溶胀比是相同凝胶含量的硅烷交联ＬＤＰＥ的４倍，１５０℃时凝胶含量为７０％的硅烷交联聚乙烯的热延伸率比相同凝胶含量的过氧化物交联聚乙烯小三倍，而且二者的结晶行为和结晶度也有很大的…

CHARACTERIZATION OF CROSSLINKING DEGREE OF LDPE VULCANIZATES

The structure and properties of peroxide crosslinked L D P Eand silane crosslinked L D P E were comparaed in gel content,equilibrium swelling ratio and high temperaturemodulus. The crosslinking densities of L D P Evulcanizates were measured by the method ofhigh temperature modulus. When the two kinds of crosslinking L D P E’s gel contents aresimilar,the crosslinked densities of peroxide crosslinking L D P Eare obviously smaller thanthose of silane crosslinked L D P E. Using equilibrium swelling ratio or crosslinked density tocharacterizethe crosslinking degree of L D P Evulcanizates is more appropriate than using gelcontent. The Huggins parameter of L D P E/boiling benzene system was also determined as0 30 .