The influences of a novel shear layer-spherulites layer alternated structure on the mechanical properties of injection-molded isotactic polypropylene

Publication date: Available online 17 June 2017
Source:Polymer
Author(s): FengYi Hou, DaShan Mi, Man Zhou, Jie Zhang
In general, the strength of injection molded objects increases with shear layer thickness or shish-kebab content. However, the effect of the change of the position of shear layer and spherulites layer on the mechanical properties is still unclear, when their thickness are fixed. To answer this question, a novel multilayer structure in which the shear layer mainly containing shish-kebab structure and spherulites layer consisted of spherulites stack alternatively was prepared by a self-designed multi-flow vibration injection molding (MFVIM) device. The results demonstrate that the impact strength can be enhanced significantly by such alternating structure, possibly because this structure is benefit for crack deflection and consequently induces more plastic deformation regions, through altering stress transfer direction and stress distribution. The tensile strength, however, is only affected little by such structure.

Graphical abstract

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