標題: Thermally stimulated current and DSC studies of the dual glass transitions in side-chain liquid crystalline copolysiloxanes containing 4-[(S)-2-methylbutoxy]phenyl 3-chloro-4-alkenyloxybenzoate side groups
作者: Chang, HL
Hsu, CS
應用化學系
Department of Applied Chemistry
公開日期: 1-十月-1997
摘要: The synthesis of side-chain liquid crystalline copolysiloxanes containing omega-[4-[4-[(S-2-methylbutoxy]phenoxycarbonyl]-2-chlorophenoxy]alkyl side groups is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffractometry reveal smectic mesomorphism for most of the obtained polymers. The copolysiloxane with three methylene units in the spacer is the only one showing no mesomorphic property. The other four copolysiloxanes, containing four, five, six or eleven methylene units in the spacer, display a smectic A phase. All of the obtained polymers present dual glass transition behavior by both DSC and thermally stimulated current (TSC) techniques. The first glass transition (T-g1) at lower temperature is due to the segmental motions of the polysiloxane backbone, while the second glass transition (T-g2) is due to the cooperative relaxation motions of spacers and mesogenic units.
URI: http://hdl.handle.net/11536/294
ISSN: 1022-1352
期刊: MACROMOLECULAR CHEMISTRY AND PHYSICS
Volume: 198
Issue: 10
起始頁: 2985
結束頁: 2992
顯示於類別:期刊論文


文件中的檔案:

  1. A1997YD55400001.pdf