An in-process ultrasonic approach to investigating the relaxation of orientation and disorientation of polymer melts

作者:Li Jiang; Sun Zhigang*; Tatibouet Jacques; Jen Cheng Kuei
来源:Polymer Engineering and Science, 2008, 48(5): 987-994.
DOI:10.1002/pen.21023

摘要

The orientation and relaxation behaviors of a low-density polyethylene melt and polypropylene melts with different melt indices undergoing a shear flow in a restricted channel were investigated by using ultrasound. A capillary rheometer was used to force the polymer melt through a slit die equipped with pressure, temperature, and ultrasound sensors, and the variation of ultrasound velocity traversing the melt was measured. Experimental results revealed that due to different mechanisms involved, the relaxations of orientation and disorientation processes show different dependences of ultrasound velocity on shear rate, temperature, and melt index.

  • 出版日期2008-5
  • 单位McGill