کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5190131 1381198 2005 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure, morphology and non-isothermal crystallization behavior of polypropylene catalloys
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Structure, morphology and non-isothermal crystallization behavior of polypropylene catalloys
چکیده انگلیسی
The structure, morphology and non-isothermal crystallization behavior of polypropylene catalloys (PP-cats) as well as pure polypropylene were investigated via differential scanning calorimeter (DSC), wide angle X-ray diffraction (WAXD) and real-time hot-stage optical microscopy (OM). The results reveal that the crystalline structures of PP-cats change with variations of the crystallization conditions and composition. The crystalline phase might consist of α-PP, β-PP and PE crystals. The content of β-PP increases with the increase of EP copolymer content and the cooling rate. At lower cooling rates, the morphologies of all non-isothermal crystallized PP-cats show spherulitic structure, and the decrease of crystal perfection and the increase of nucleation density of PP-cats system could be evidently observed. Considering the compositions of PP-cats, these indicated that the interactions between propylene homopolymer and the ethylene-propylene copolymers (both random and block ones) are in favor of the enhancement of the nucleation ability of α-form as well as β-form. In comparison with pure PP, the overall crystallization rates of the PP-cats increase dramatically, while the growth rates of the spherulites in all PP-cats decrease distinctly under the given cooling conditions. These experimental results were explained on the basis of diluting effect and obstructing effect on the mobility of PP chains in the ethylene-propylene copolymer.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 9, 15 April 2005, Pages 3163-3174
نویسندگان
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