弹性体共混改性聚丙烯的增韧机理

阐述了以聚丙烯（ＰＰ）／高密度聚乙烯（ＨＤＰＥ）为复合基体，苯乙烯－丁二烯－苯乙烯（ＳＢＳ）为增韧剂经三元共混所得的性能优异的一类新材料．从三个层次（形貌结构转变、宏观力学响应和裂尖过程区演化）系统地探讨了其增韧机理．结果表明由形貌结构控制和对早期体膨胀变形抑制可造成裂尖平面应变区的超钝化从而达到增韧．

TOUGHENING MECHANISMS OF POLYPROPYLENE BLENDS MODIFIED BY ELASTOMER

new class of materials featuring PP/HDPE composite matrix modified by SBS toughening agent are explored. Excellent mechanical properties are offered by the present three component blending materials. Furthermore, a systematic discussion on the toughening mechanisms of the said material system is conducted from three different but mutually connected viewpoints, namely the morphology structures, the macroscopic mechanics response and the evolution of the crack tip profile. The investigation indicates that toughening can be achieved by the superblunted crack tip in the plane strain portion of the crack profile, and the developmellt of crack tip superblunting is resulted by controlling the material morphology and the suppressing on the early evolution of the dilatational deformation.