Influence of annealing on the morphology and mechanical properties of iPP/HDPE blend with tailored oriented crystalline structures

摘要

In this article, two kinds of isotactic polypropylene (iPP)/high density molecular weight polyethylene (HDPE) blend samples were prepared by an accessible injection-molding method. These two samples contain iPP shish kebab matrix and HDPE dispersed phase (shish kebab and epitaxy crystal, respectively). The variation of microstructures upon annealing was characterized using scanning electron microscopy, differential scanning calorimetry and small-angle X-ray scattering. It was found that the variations of different crystalline structures were changed by varying annealing parameters. Only the rearrangement of partially melted chains into primary lamellae happened for the sample with epitaxy crystalline structure, which was distinguished from the sample with HDPE shish kebab structure. Moreover, the variation of the crystalline structure, crystallinity and melting point were discussed to account for the changes in mechanical properties. These results revealed the relationship among the morphology, annealing parameters and mechanical properties, which provide a practical method to industrial manufacture.