Crystalline morphology of β-nucleated controlled-rheology polypropylene

A series of controlled-rheology polypropylenes (CRPPs) were prepared through reactive extrusion of polypropylene (PP) and dicumyl peroxide (DCP). Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were used to evaluate the ability of three different kinds of nucleating agents (NAs), E3B, WBG-II, and TMB-5, to induce β-crystals in the CRPPs. The results indicate that TMB-5 shows the best nucleation effect and can induce the highest relative content of β-crystals. For the effect of DCP content on the β-crystal of CRPP, it was found that with 0.3 wt% TMB-5 incorporated, the critical DCP content emerged at 0.1 wt%. For the effect of NA content on the β-crystal of CRPPs, the total β-crystallinity index and relative β-crystal content were found to reach a maximum value at a content of 0.5 wt% β-NA, with a 0.1 wt% DCP content incorporated.