Impact of Crosslinking Density on Liquid Crystal Elastomer Properties

Abstract

Liquid crystal elastomers have unique properties that enable them to be used in various electrical and biological fields. Properties like soft elasticity and temperature-dependent actuation are tunable and therefore are promising in situations where certain conditions need to be met. To tune transition temperatures, molecular (mesogen-mesogen) interactions, and the material’s network structure need to be controlled. In this thesis, it was first attempted to reduce network heterogeneity by decreasing the molecular weight distribution of the LCE polymer precursor. Liquid-liquid fractionation effectively separated the LCE polymer precursor into fractions of controlled molecular weights but not in a sufficiently scalable manner. Therefore, the impacts of crosslinking density on material glass transition and transitions in liquid crystalline order were investigated. Furthermore, differences in stress-strain properties were explored.