Photocrosslinkable Liquid Crystal Main-Chain Polymers: Thin Films and Electrospinning

✍ Scribed by Simon Krause; Roland Dersch; Joachim H. Wendorff; Heino Finkelmann

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 246 KB
• Volume: 28
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200700460

✦ Synopsis

Abstract

For mechanical actuators, a response to external stimuli is required. Main‐chain liquid crystal elastomers (MCLCEs) show high response to changes in temperature especially in the vicinity of a phase transition. Most of these crosslinked materials were synthesized in a one‐step reaction which leads to a macroscopically aligned elastomer. Up to now only macroscopic samples have been prepared. We are presenting a new approach which allows us to prepare thin films as well as aligned fibers. First a liquid crystalline main‐chain polymer with a photoactive moiety was synthesized, which was oriented by a mechanical field and photocrosslinked. The thin films show exceptional mechanical properties such as large temperature‐dependent changes in length and a nonlinear stress–strain relation. To obtain fibers, we used the electrospinning process from solution with in situ UV curing. We obtained crosslinked fibers with a uniform alignment of the nematic director.

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