Multifunctional Thermally Reversible Nanostructured Thermosetting Materials Based on Block Copolymers Dispersed Liquid Crystal

✍ Scribed by Agnieszka Tercjak; Elena Serrano; Iñaki Mondragon

• Book ID: 102495330
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 198 KB
• Volume: 28
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200600893

✦ Synopsis

Abstract

Thermally reversible nanostructured thermosetting materials are prepared for the first time by modification of an epoxy resin with 5 wt.‐% of an amphiphilic polystyrene‐block‐poly(ethylene oxide) block copolymer (PSEO) and 30 wt.‐% of a low‐molecular‐weight liquid crystal, 4__′__‐(hexyl)‐4‐biphenylcarbonitrile (HBC). The epoxy system modified with 5 wt.‐% PSEO amphiphilic copolymer self‐assembles into spherical microdomains with a size distribution between 32 and 45 nm in diameter. Under the same conditions, the modification of an epoxy system with 5 wt.‐% PSEO and 30 wt.‐% HBC leads to a micro‐phase separated PS‐rich domains embedded in a HBC phase. The morphology of this nanostructured thermosetting system consists in a higher amount of spherical microdomains of PSEO/HBC with the size distribution between 40 and 75 nm in diameter. This implies that the separation of the PS‐rich phase provokes the separation of the liquid crystal and allows one to obtain a novel thermally switchable smart material.

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