首页   按字顺浏览 期刊浏览 卷期浏览 Thermal behavior and structure of liquid-crystalline aromatic-aliphatic polyester/poly(...
Thermal behavior and structure of liquid-crystalline aromatic-aliphatic polyester/poly(tetramethylene oxide) block copolymers

 

作者: T. Takahashi,   F. Nagata,  

 

期刊: Journal of Macromolecular Science, Part B  (Taylor Available online 1991)
卷期: Volume 30, issue 1-2  

页码: 25-39

 

ISSN:0022-2348

 

年代: 1991

 

DOI:10.1080/00222349108245781

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

The thermal behavior and structure of poly(hexamethylenep,p′-biben-zoate) (BB-6)/poly(tetramethyleneoxide) (PTMO) block copolymers (BB-6/PTMO) were studied using differential scanning calorimetry, polarizing optical microscopy, and wide-angle and small-angle x-ray diffractometry. As the PTMO fraction increases, BB-6 liquid crystallinity decreased and two transition temperatures [Tc→M (crystal-mesophase) andTm→i (mesophase-isotropic melt)] move to lower temperatures. BB-6/PTMO containing less than 20 mol% of PTMO retains liquid crystallinity. The isotropic melt-mesophase transition exotherm of BB-6/PTMO in the cooling process moves to lower temperature with increasing PTMO. Contrary to the isotropic melt-mesophase transition, the mesophase-crystal transition exotherm moves to higher temperature, indicating that PTMO segments favor the molecular mobility of BB-6 segments. As the mole fraction of BB-6 increases, the texture indicative of the smectic liquid crystal is gradually disorganized. BB-6/PTMO containing more than 30 mol% of PTMO no longer forms the texture indicative of smectic liquid crystals.

 

点击下载:  PDF (785KB)



返 回