Morphologies of injection molded isotactic polypropylene/ultra high molecular weight polyethylene blends

The morphologies in isotactic polypropylene (iPP)/ultra high molecular weight polyethylene (UHMWPE) blend prepared with a Minijet injection molding machine have been studied. It is found that both the shear effect and the addition of UHMWPE greatly influence the morphologies of the PP matrix. Shish-kebabs and β-cylindrite morphology can be observed simultaneously in the subskin, where the shear effect is believed to be the greatest. With the increasing of the content of UHMWPE, the morphology of shish-kebab or β-cylindrite structures become more conspicuous. The diameter and the distance between the row nuclei of the β-cylindrites both increase as the location gradually moves to the center of the sample.

Schematic of the hierarchical crystalline structure in iPP/UHMWPE blends.Figure optionsDownload as PowerPoint slideHighlights
► We prepared iPP/UHMWPE blends with various UHMWPE content.
► Shish-kebabs and β-cylindrite were observed simultaneously.
► With increasing content of UHMWPE, shish-kebabs and β-cylindrites become more conspicuous.