不同冲击断裂方式下橡胶粒子形态对HIPS脆韧转变的影响

核-壳型/蜂窝型高抗冲聚苯乙烯(HIPS)树脂在Izod冲击和落锤冲击断裂过程中的脆-韧转变行为不同。透射电镜(TEM)对亚断裂形变区的观察表明,蜂窝型HIPS对落锤冲击作用下的脆韧转变敏感,应力集中能有效引发基体的塑性形变,呈韧性断裂,但在v-notched Izod冲击断裂过程中,却呈脆性;而核-壳型HIPS的冲击断裂性能与之相反。将LDO假说引入冲击破坏研究并结合损伤竞争准数Da和Vincent图探讨了分散相特性及冲击方式对脆韧转变行为的影响。

Influence of Rubber Particles on the Brittle-Ductile Transition of HIPS Induced by F-and VI-Impact Fracture

The brittle-ductile transition behavior of v-notched Izod?impact (VI-impact) of core-shell and occluded type high impact polystyrene (HIPS) shows a different trend from falling dart impact (F-impact).Transmission electron microscope (TEM) observation demonstrates that the occluded-rubber particles could facilitate the plastic deformation arise from stress concentration,and gains well toughness with a F-impact strength of 186 Inlb.On the contrary,the occluded rubber particle seems to inhibit the expansion of the matrix during the VI-impact and failure in a brittle mode of 53J/m.In comparison,the core-shell rubber particle has been elongated into thinner domains and lots of cavitations appeared in the VI-impact fractured whiten zone.Influence of the rubber particles morphology and composition on the brittle-ductile transition behavior of HIPS and energy releasing has been explored by using the damage competition mechanism Da and Vincent diagram.