کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5187159 1381122 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rheological studies on the quasi-quiescent crystallization of polypropylene nanocomposites
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Rheological studies on the quasi-quiescent crystallization of polypropylene nanocomposites
چکیده انگلیسی

Isothermal crystallization of isotactic polypropylene (iPP)/organic montmorillonite (OMMT) binary nanocomposite and iPP/OMMT/poly(ethylene-co-octene) (PEOc) ternary nanocomposites has been investigated by polarized optical microscopy (POM), rheometry and scanning electron microscopy (SEM). At the stage of nucleation the heterogeneous nucleation effect of OMMT was much greater than the concentration fluctuation assisted nucleation effect in the ternary nanocomposite. Besides, PEOc played a role of inhibitor of OMMT nucleation agents at the nucleation stage because many of OMMT layers were distributed around PEOc-rich domains. At stage II of the crystal growth process, the entanglement effect of PEOc greatly affected the rheological response (storage modulus (G′) and its growth rate) due to the long side chains of PEOc component. In stage III of the growth process, OMMT layers and the entanglement of PEOc chains limited the motion of polypropylene chains. So the growth rate of G′ was slowed down. During the shrinkage and cooling process after isothermal crystallization, some fibril links between the spherulites, consisting of PEOc chains and iPP chains, were formed from the amorphous phases surrounding the spherulites.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 49, Issue 11, 27 May 2008, Pages 2717-2727
نویسندگان
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