热引发官能化HDPE、PP、EPDM及其增韧PA66研究

采用热引发熔融接技方法研究了不同反应条件下马来酸酐（MAH）接枝HDPE、接枝共聚PP及接枝EPDM弹性体的接枝反应。结果表明：本热引发接枝法可避免接枝过程中的交联副反应，制得具有较高接枝率（接枝率在0.3%以上），较好熔体流动性能，较少凝胶含量的马来酸酐接枝HDPE、接枝共聚PP及接枝EPDM。采用机械共混法对已官能化的聚烯烃弹性体和聚烯烃塑料分别和混合增韧PA66的情况进行了比较，结果显示：采用PA66／改性聚烯烃弹性体／改性聚烯烃塑料三元共混体系，可以在较少用量的改性橡胶条件下使PA66的缺口冲击强度达到原材料的10倍以上，并且材料弯曲模量损失减少。SEM对PA66／EPDM－g-MHA/PP-g-MAH三元共混体系脆韧转变的研究结果表明：体系分散相中的EPDM－g-MAH向PA66基体扩散、渗透或形成嵌段共聚物的部分是增韧PA66中的有效成分。

Reseach of Heat Initiated Functionalization of HDPE,PP and EPDM and Their Products Toughened PA66

The graft reaction of MAH grafted HDPE,PP and EPDM at various conditions is studied by means of polyolefin grafted MAH in melt via heat initiation.The results show that the cross-linking reaction in the functionalization process can be avoided and the grafted product with a higher grafting degree (more than 0.3 percent) and a better melt flowability as well as less gel can be obtained. The toughened efficiency of these blends by blending nylon/functionalized plastics,nylon/functionalized rubber and nylon/functionalized rubber/functionalized plastics were compared by mechanic blending. The results show that the Charpy impact strength of the ternary blends,such as PA/EPDM-g-MAH/PP-g-MAH,can be 10 times than that of unimproved ones with a lower EPDM-g-MAH contents. Compared with PA/EPDM-g-MAH blend,the bending modulus of the blend lose less.Research on the brittle-ductile transition of PA66/EPDM-g-MAH/PP-g-MAH ternary blending by SEM shows that the effective part to toughen PA66 is that of the diffusion,penetration of EPDM-g-MAH in the dispersion phase into PA66 or that of forming block copolymer.