کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5184914 1381061 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Shear-induced orientation in the crystallization of an isotactic polypropylene nanocomposite
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Shear-induced orientation in the crystallization of an isotactic polypropylene nanocomposite
چکیده انگلیسی

Isothermal crystallization of isotactic polypropylene (iPP)/organic montmorillonite (OMMT) binary composite under shear field was investigated by in situ polarized optical microscopy, rheometry and transmission electron microscopy. When shear strain was small, shear flow could enhance the crystallization of iPP, and the crystallizing entity was spherulitic in iPP/OMMT composite in which the OMMT content was below the percolation threshold. With shear strain increasing, the orientation extent became stronger and cylindrites and strings of spherulites appeared in these samples. However, for iPP/OMMT composite with OMMT content higher than the percolation threshold, when the shear strain was not big enough to destroy the fillers network in the matrix, the crystallization of iPP was similar with that of the un-sheared sample. When shear strain was large enough, the fillers network was destroyed and clay layers were aligned along the flow direction. There formed oriented crystals including cylindrites and strings of spherulites, which were much smaller in size than those formed in the previous case, because the aligned clay layers acted as heterogeneous nucleation agents to promote crystallization of iPP.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 50, Issue 11, 22 May 2009, Pages 2465-2471
نویسندگان
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