LIQUID-CRYSTALLINE ELASTOMERS

Liquid-crystalline elastomers are produced by the introduction of crosslinking into liquid-crystalline polymer systems. This crosslinking results in materials with a number of unusual properties. Of particular note are the effects of an applied stress coupled with such a system. Theory predicts that these should include stress-induced phase transitions and spontaneous elongation of samples in the liquid-crystalline phase; such properties have now been observed experimentally. The materials exhibit a number of other properties, also induced by the coupling of network elasticity to the liquid-crystalline phase. These include a temperature-induced memory effect; materials with a chiral mesophase exhibit piezoelectric behaviour.