کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5183970 1381034 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecular weight dependence of growth and morphology of it-poly(butene-1) spherulites
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Molecular weight dependence of growth and morphology of it-poly(butene-1) spherulites
چکیده انگلیسی

Molecular weight dependence of growth and morphology of spherulites of isotactic poly(butene-1), iPB-1, and those of the mixtures with atactic poly(butene-1), aPB-1, were examined by atomic force microscopy (AFM) and polarizing optical microscopy (POM) in order to examine the mechanism of the structural evolution by the branching and re-orientation of lamellar crystals at the growth front. The width of lamellar crystals and the characteristic size of the inner structure of spherulites decreased with increasing molecular weight. The result suggests that the mobility of the melt determines the sizes in spherulites and supports the growth front instability induced by a gradient triggering the branching. The sizes in the mixtures also decreased with increasing weight-averaged molecular weight, Mw. The size dependence in low Mw region, however, was too strong and that in high Mw was too weak in comparison with the predicted dependence for the prepared Mw. It has been concluded that the peculiar behaviors should be discussed with effective Mw influenced by the occurrence of separation and exclusion of non-crystallizing aPB-1 at the growth front.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 52, Issue 9, 19 April 2011, Pages 2051-2058
نویسندگان
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