Changes of crystallinity and spherulite morphology in isotactic polypropylene after rolling and heat

来源 :Journal of University of Science and Technology Beijing | 被引量 : 0次 | 上传用户:younger666
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The spherulite morphology of the rolled and subsequent heat-treated isotactic polypropylene (iPP) was observed by polarized microscopy, and the crystallinity evolution of materials was also measured by the wide angle X-ray scattering (WAXS). Rolling led to the oblate spherulites in the deformed iPP samples. The sheared crystalline lamellae broke apart into sets of crystalline blocks during rolling. As a result, the crystallinity of the iPP samples was greatly reduced during deformation, which induced the unclear spherulites and spherulite boundaries. Subsequent heat treatment resulted in the strong recrystallization of the rolled iPP samples. But the recrystallization in this work only meant the rearrangement of the macromolecule along the unbroken crystalline lamellae and the existing small crystalline blocks in the deformed spherulites. Heat treatment did not change the shape of the spherulites formed during deformation. The recrystallization also resulted in very clear spherulites and spherulite boundaries. The spherulite morphology of the rolled and subsequent heat-treated isotactic polypropylene (iPP) was observed by polarized microscopy, and the crystallinity evolution of materials was also measured by the wide angle X-ray scattering (WAXS). Rolling led to the oblate spherulites in the sheared crystalline lamellae broke apart into sets of crystalline blocks during rolling. As a result, the crystallinity of the unclear spherulites and spherulite boundaries. strong recrystallization of the rolled iPP samples. But the recrystallization in this work only only the rearrangement of the macromolecule along the unbroken crystalline lamellae and the existing small crystalline blocks in the deformed spherulites. Heat treatment did not change the shape of the spherulites formed during deformation . The recrystallization also resulted in very clear spherulites a nd spherulite boundaries.
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