Revitalized β‐form crystal during the remelting and recrystallization processes in isotactic polypropylene/glass fiber composites
writer：Yijing Qin, Liying Zhang, Xiaobei Guo, Kun Dai, Dirk W. Schubert, Guoqiang Zheng(通訊作者), Chuntai
keywords：β-form crystal, crystalline memory effect, isotactic polypropylene, remelting-recrystallization
source：期刊
specific source：Polymer Crystallization, 2018,1: 1-7
Issue time：2018年
Under different pre-shear temperatures, an interfacial sheath structure is fabricated by pulling a single glass fiber in isotactic polypropylene melt. The thermal stability of sheath structure and “crystalline memory effect” of β-form crystal are studied thermo-optically. The thermal stability of primary sheath structure is influenced by the orientation of molecular chains and pre-shear temperature. During tens of remelting and recrystallization processes, the number of “revitalized” β-form crystal generally decreases. However, the nucleation density of α-form crystal exhibits no obvious change, indicating that a-form crystal has stronger “crystalline memory effect” than that of β-form crystal. More interestingly, some crystal nuclei of β-form crystal can “revitalize” continuously or fitfully during the recrystallization. The findings preliminarily indicate that “crystalline memory effect” of β-form crystal might not only depend on the orientation level of molecular chains of sheath structure, but also depend on the spatial arrangement of fibrillar lamellae in sheath structure