کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5207714 | 1382364 | 2007 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Degradation of polypropylene (PP) during multiple extrusions: Thermal analysis, mechanical properties and analysis of variance
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The effects of repetitive extrusion cycles at different die temperatures in a single screw extruder were investigated by thermal analysis (degree of crystallinity (Ïc), heat of fusion (ÎHm), melting temperature (Tm) and the onset melting temperature (Tonset,m)) and mechanical properties (tensile and impact strength). Also, analysis of variance (ANOVA) and response surface methodology (RSM) were employed for modeling and analysis of the mechanical property results. Thermal analysis verified an increase for Ïc and ÎHm with a continuous reduction in the Tm and Tonset,m values with increase of die temperature and/or cycles of extrusion. For mechanical properties, the observed degradation process only slightly affects the small strain properties (yield stress and modulus) and impact strength. Break properties (break stress, break strain and energy to break) were reduced significantly by the experimental conditions adopted. According to ANOVA and RSM, the degradation process was occasioned more by high shear rate (repetitive number of cycles) than by high processing temperatures.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Testing - Volume 26, Issue 5, August 2007, Pages 676-684
Journal: Polymer Testing - Volume 26, Issue 5, August 2007, Pages 676-684
نویسندگان
Helson M. da Costa, Valéria D. Ramos, Márcia G. de Oliveira,