Influence of swelling on the shear mechanical properties of monodomain side-chain liquid-crystal elastomers: Gaussian versus Non-Gaussian elasticity

摘要

The shear mechanical properties of nematic side-chain liquid-crystal elastomers swollen with a nematic solvent are studied. The results show that the elasticity of the network is Gaussian for elastomers oriented before crosslinking and non-Gaussian for the usual twice-crosslinked elastomers oriented by stretching the network formed after the first crosslinking step. For systems oriented before crosslinking, a crossover between Gaussian and non- Gaussian behavior is observed at a particular weight concentration of solvent. In contrast to the current belief, the neoclassical model based on Gaussian rubber elasticity cannot provide a correct description of the twice-crosslinked systems. The shear modulus of nematic side-chain liquid-crystal elastomers swollen with a nematic solvent is studied. Elasticity is Gaussian for systems oriented before crosslinking and non-Gaussian for systems oriented by stretching the network formed during its synthesis. For systems oriented before crosslinking, a crossover between Gaussian and non-Gaussian behavior is observed at a particular solvent concentration.