The Coupling Effect of Force Field and Temperature on β-form Crystal of Polycrystalline Composition of Block Copolymer Polypropylene

Polycrystalline regulation has crucial influence on improving mechanical properties of polypropylene. The β-form crystal composition changes in block co-polymer polypropylene (PP-B) affected by the coupling effect of force field and temperature field, in this article, was systematic studied via changing shear temperature and shear rate as well as the cooling rate after shearing. The results indicate that there are the optimal combination conditions of force field and temperature to promote β-form crystal formation in PP-B. At low melt temperature, increasing shear rate and cooling rate in an appropriate range can significantly improve the relative content of β-crystal, up to 63%; however, exorbitant shear rate and cooling rate help to restrain the growth of β-crystal.