Please use this identifier to cite or link to this item: http://hdl.handle.net/1783.1/17200

Experimental measurement and numerical simulation of viscosity reduction effects in HMMPE containing a small amount of exfoliated organoclay-modified TLCP composite

Authors Tang, You Hong
Gao, Ping View this author's profile
Ye, Lin
Zhao, Chengbi
Issue Date 2010
Source Polymer , v. 51, (2), 2010, JAN 21, p. 514-521
Summary A small amount (1 wt\%) of organoclay-modified thermotropic liquid crystalline polymer (TLCP) acting as a viscosity reduction agent in high molecular mass polyethylene (HMMPE) was characterized and compared with purified TLCP (I wt\%) in HMMPE at 190 degrees C and 230 degrees C, respectively, where the TLCP displayed nematic and nematic-isotropic biphase structures. In the TLCP/PE blend at 190 degrees C and 230 degrees C, dramatic reductions in viscosity were observed with significant improvement in extrudate surface smoothness and an enlarged processing window. For the organoclay-modified TLCP in PE, the viscosity reduction ability of TLCP was further enhanced with viscosity dropped by up to >98.5\% and >97.4\% at 190 degrees C and 230 degrees C and processing window enlarged to >700 s(-1) and >900 s(-1) respectively in comparison to that of PE. Moreover, yielding stress, initial transition shear rate and transition region decreased to lower magnitudes than those of the TLCP/PE blend. A phenomenological model was applied to elucidate the mechanism of organoclay, TLCP and PE conformation before and after yielding in the confined capillary environment. A binary flow pattern model was applied to successfully predict the rheological behavior of the blends at 190 degrees C. (C) 2009 Elsevier Ltd. All rights reserved.
Subjects
ISSN 0032-3861
Language English
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