標題: The role of transesterification on the miscibility in blends of polycarbonate and liquid crystalline copolyester
作者: Wei, KH
Ho, JC
交大名義發表
材料科學與工程學系
National Chiao Tung University
Department of Materials Science and Engineering
公開日期: 24-三月-1997
摘要: Transesterification mechanisms and rate in blends of polycarbonate (PC) and random liquid crystalline polyester copoly(oxybenzoate-p-terephthalate) at molar ratio 40/60 (P46) were studied through a five-component diad analysis and with C-13 and H-1-C-13 nuclear magnetic resonance spectroscopy. It was found that the ester-ester interchange in the two polymers took place within 15 min when the blend was annealed at 260 degrees C in vacuum. In the annealed blend, the Bisphenol A unit in polycarbonate reacted first with the terephthalate unit and then with the oxybenzoate unit in copoly(oxybenzoate-p-terephthalate). As the transesterification in the blend continued for about 1 h, the forming of dad Bisphenol A-oxybenzoate exceeded that of diad Bisphenol A-terephthalate. This large loss (57%) of the diad oxybenzoate-oxybenzoate caused the disappearance of the liquid crystalline phase in the blend. In sharp contrast to the originally immiscible blend of PC and P46 (two distinctive glass transition temperatures), the large loss of the liquid crystalline diad resulted in complete miscibility in the annealed blend, as evidenced by the appearance of a single glass transition temperature in the differential scanning calorimetry measurement.
URI: http://hdl.handle.net/11536/660
ISSN: 0024-9297
期刊: MACROMOLECULES
Volume: 30
Issue: 6
起始頁: 1587
結束頁: 1593
顯示於類別:期刊論文


文件中的檔案:

  1. A1997WP90900009.pdf