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

Huey Ling Chang, Chain-Shu Hsu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

The synthesis of side-chain liquid crystalline copolysiloxanes containing ω-[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 (Tg1) at lower temperature is due to the segmental motions of the polysiloxane backbone, while the second glass transition (Tg2) is due to the cooperative relaxation motions of spacers and mesogenic units.

Original languageEnglish
Pages (from-to)2985-2992
Number of pages8
JournalMacromolecular Chemistry and Physics
Volume198
Issue number10
DOIs
StatePublished - 1 Jan 1997

Fingerprint Dive into the research topics of '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'. Together they form a unique fingerprint.

Cite this