电子辐照交联乙烯－甲基丙烯酸甲酯共聚物的研究

摘要

In order to research and develop the heat shrinkable sleeve with the ethylene -methyl methacrylate copoly-mer (EMMA) and the silicon rubber blends , the effect of electron beam radiation on the EMMA cross -linking was studied.The EMMA containing 18% MMA was made into 1.0 mm thick slices.The slices were irradiated in the air by the scanning electron beam of DD1.2 high frequency, high voltage electron accelerator and the gel content , DSC characteristics and mechanical properties of the EMMA irradiated were tested .The results showed that within the range of 0 ~110 kGy, when the electron irradiation dose is higher than 25 kGy, the gel content rises along with increasing electron irradiation dose and when the irradiation dose is 75.2 kGy, the gel content is more than 58.6%.The crystallization peak temperature of the EMMA is reduced along with increasing electron irradiation dose; as the dose increases, the tensile strength of the EMMA has the maximum value at the 63kGry dose.After the electron beam irradiation, the hardness of the EMMA increases a little.Using the EMMA and silicon rubber blends, the soft radiation cross-linking heat-shrinkable sleeves can be made.%　　为了研制含有乙烯－甲基丙烯酸甲酯共聚物（EMMA）和硅橡胶共混物的热收缩套管，研究了电子辐照对 EMMA的辐射交联作用．将 MMA 含量18％的 EMMA 制成厚度1．0 mm 的薄片和0．25 mm 厚的薄膜，用 DD1．2型高频高压电子加速器扫描电子束，在空气中辐照 EMMA 样品，测试电子辐照的 EMMA 凝胶含量、DSC 特性及力学性能．结果表明，在0～110 kGy 辐照剂量内，当辐照剂量高于25 kGy 时，EMMA 的凝胶含量随着辐照剂量的增加而增加；当辐照剂量约75．2kGy 时，凝胶含量达58．6％；EMMA 峰值温度随着电子辐照剂量的增加而降低；EMMA 拉伸强度随着辐照剂量的增加在63 kGy 附近达到最大值；电子辐照的 EMMA 硬度稍有增加．利用 EMMA 和硅橡胶的共混物可以制成柔软的辐射交联热收缩套管．