中文摘要：

进行乙烯-辛烯嵌段型共聚物（OBC）共混改性共聚级聚丙烯（Co-PP）的研究,考察了共混物的冲击强度、拉伸强度、断裂伸长率、熔体流动指数、维卡软化点等机械物理性能和冲击断面形貌,进行了动态力学分析,并与Co-PP/乙烯-辛烯无规共聚物（POE）、Co-PP/乙烯-丁烯共聚物（EBC）共混体系比较。结果表明,弹性体含量达到10%（wt）时,三种共混体系均已基本实现＂脆韧转变＂,含较长支链的OBC与POE对Co-PP有更好的增韧效果;低温下,Co-PP/OBC的抗冲性能尤佳,其低温内耗峰温度低、储能模量高。OBC大分子链中PE嵌段的存在,使其自身及其与Co-PP共混物的加工与耐热性均明显优于其它两种弹性体。

英文摘要：

Compared with the polyolefin elastomers of ethylene-octene random copolymer （POE） and ethylene-butene random copolymer （EBC）,a new polyolefin elastomer,ethylene-octene block copolymer （OBC）,was used to blend with copolymerized polypropylene （Co-PP） and to form the toughening modified Co-PP alloy. The mechanical and physical properties of the toughening modified alloys,such as impact strength,tensile strength,elongation at break,melt flow index,Vicat softening point and morphologies of the impact fracture surface,were investigated. The dynamic mechanics of the alloys were analyzed too. The results show that all the three kinds of Co-PP alloys （Co-PP/OBC,Co-PP/POE and Co-PP/EBC） have almost accomplished the ＂brittle-ductile transition＂ when their elastomer content is higher than 10%（wt）,and both the ethylene-octene copolymers （OBC and POE） with longer branched chains have better toughening effect on Co-PP. Especially at low temperatures,the Co-PP/OBC alloy has higher impact strength,storage modulus and lower loss peak temperature. Since there is polyethylene blocks existing in the chains of OBC,both OBC and its alloy with Co-PP have better processability and higher thermal deformation temperature.