LAUSR

Two pure impact copolymer polypropylenes (ICP), one pure homo-polypropylene (HPP) and their compounds with different type and fraction of Vistamaxx™ propylene-based elastomer (“Vistamaxx”) were used to investigate the stress whitening activated in the impact processes via ultra-small-angle X-ray scattering technique. The whitening presented in ICP is confirmed to be caused by the interfaces existed between ethylene-propylene (EP) rubber and polypropylene matrix, such kind whitening is apparently unlike the one initiated in the crystal phase of HPP. In this study, Vistamaxx with high crystallinity can adjust the compatibility of EP rubber and PP matrix which results in a reduction of interfaces, thus, a phenomenon of reduced stress whitening can be observed in blends of ICP with Vistamaxx. However, the enhancement of stress whitening can be found in blends of ICP with Vistamaxx which occupied low crystallinity. Such behaviors can be assigned to the poor compatibility between Vistamaxx and PP matrix. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 133, 44747.