LIQUID-CRYSTALLINE ELASTOMERS

Liquid-crystalline elastomers are produced by the introduction of cros slinking into liquid-crystalline polymer systems. This crosslinking re sults 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 transit ions and spontaneous elongation of samples in the liquid-crystalline p hase; such properties have now been observed experimentally. The mater ials exhibit a number of other properties, also induced by the couplin g of network elasticity to the liquid-crystalline phase. These include a temperature-induced memory effect; materials with a chiral mesophas e exhibit piezoelectric behaviour.