不同弹性体对聚丙烯的协同增韧

Synergistic Toughening Effect of Different Elastomers on Polypropylene

以弹性体乙烯-α-辛烯共聚物(POE)、苯乙烯-乙烯/丁烯-苯乙烯共聚物(SEBS)和SEBS/POE作为增韧剂,对不同弹性体协同增韧聚丙烯进行了研究,考察了共混体系的力学性能、结晶行为、结晶形貌、动态力学分析以及低温脆断面形貌。结果表明,弹性体SEBS、POE均对PP具有增韧作用,当SEBS、POE用量分别为20%、25%时完成了"脆韧转变",其中SEBS增韧效果较佳;SEBS、POE作为弹性体加入,使PP的结晶度降低;当SEBS/POE复配增韧PP,且m(PP)/m(SEBS)/m(POE)=70/20/10时,具有协同增韧效应,冲击强度最高;此外,POE在PP/SEBS复配增韧中相当于相容剂,起到了"桥梁"作用。

In order to improve the low impact strength of polypropylene （PP）, elastomers ethylene-a-olefin copolymer （POE）, styrene-b-ethylene-co-butylene-b-styrene （SEBS）, SEBS/POE were used as toughening agents. The mechanical properties, crystallization behavior, crystal morphology, dynamic mechanical analysis and lowtemperature brittle fracture surface of the blends were investigated. The result show that SEBS and POE have toughening effect on PP. When mass fraction of SEBS, POE is 20% and 25%, respectively, the ＂brittle-ductile transition＂ occurs, and SEBS shows the better toughening effect. The reason is that SEBS and POE, as elastomers, reduce the crystallization of PP. When the blend SEBS/POE toughens PP with the proportion of rn （PP）/m （SEBS）/m （POE） = 70/20/10, the impact becomes highest. The SEM results show that POE is likely the compatibilizer in PP/SEBS compound, just as the role of ＂bridge＂.