The effect of the molecular weight on the static electro- optic properties of methacrylate based side-chain liquid crystal polymers

Abstract EN

A series of methacrylate based side chain liquid polymers have been prepared with a range of molecular weight.

For the high molecular weight polymers, a smectic phase is observed with a very narrow nematic range.

However at low molecular weight only the nematic phase is observed.

A Marked reduction in Tg, Tsn and Tni a function of reducing the molecular weight have been observed.

Infrared dichroism measurements-have been made to determine the order parameters of the Liquid crystslline side chain polymers.

It is found that the higher the molecular weight of the polymer the higher the threshold voltage of the electro- optic response, and the lower the order parameter.

The increase in the threshold voltage with increasing molecular weight may be related to the intrinsic curvature elasticity and hence to the coupling between mesogenic units and the polymer.