A main-chain smectic-C liquid crystalline elastomer that displays shape memory properties was synthesized by reacting vinyl-terminated mesogens and a tetravinyl crosslinker with hydride-terminated poly(dimethylsiloxane). This elastomer has a low modulus (E' less than 100 MPa above 0 �C) that decreases in a stepwise fashion upon heating due to a combined mesogen glass transition and an isotropization transition. Previous studies have shown that the LCE described herein has excellent one-way shape memory properties, and shape fixing has been attributed to the vitrification of the mesogens within the smectic layers. The unusual ability of an elastomer to function as a shape memory material above room temperature was investigated by studying the microstructure of a LCE recovering from a fixed state at different temperatures using wide-angle x-ray scattering. Analysis of the scattering patterns showed that the smectic layers thicken and the chevron microstructure changes with strain recovery.

Evolution of microstructure during strain recovery of a shape memory liquid crystalline elastomer

240th National Meeting (2010)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.