کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5190740 1381216 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A phenomenological model for the viscosity reductions in blends of HMMPE containing a small quantity of thermotropic liquid crystalline copolyester HBA/HQ/SA
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
A phenomenological model for the viscosity reductions in blends of HMMPE containing a small quantity of thermotropic liquid crystalline copolyester HBA/HQ/SA
چکیده انگلیسی

In this paper, we present a phenomenological model for the viscosity changes in bulk high molecular mass polyethylene (HMMPE) due to the addition of a very small quantity of a main chain longitudinal thermotropic liquid crystalline polymer (TLCP) containing flexible spacers. The chain alignment in the elongated TLCP domains causes chain alignment and disengagement in the neighboring HMMPE melt. In converging capillary flows, this occurs at a certain critical centerline velocity. After the onset of such transition, melt of elongated chain conformations forms from the center core and expands towards the capillary wall with increasing flow rates. The model successfully predicts both the drastic viscosity reduction effects and the critical yield stress in the HMMPE+TLCP blends without any adjustable parameters. Our model is also applicable to other systems that undergo flow-induced phase transitions, e.g. in biphasic liquid crystalline polymer melts.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 19, 8 September 2005, Pages 8151-8156
نویسندگان
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