The Influence of Non – Polar Group on the Properties of Poly-Siloxanes Side Chain Liquid Crystal Polymers

Abstract

The purpose of this work is to know the effect of adding non-Polar group to a group of polymers based on the poly-siloxane backbone. It is found that adding the non-polar group would reduce the contribution of the dipole moment of the cyano - group parallel to the molecular long axis of the mesogenic unit and lead to a suppression of dielectric anisotropic (∆ε) for the system. The five samples different molecular weight and equal flexible spacer have been prepared. The intensity coming out of the polarizer be high E=0 but when apply a little of the electric field reduced intensity. The complete switching voltage increases with increasing molecular weight. The increase in temperature leads to decrease in response times (on, off) which is due to the decrease in the viscosity of the polymer. The increases order parameter whenever decreases molecular weight, this was attributed to the degree of cross-link that get in the molecules of the material are few. The effect of the low molecular weight of the polymer reduces the threshold voltage and that it is possible to have relationship an increase flexible spacer of polymer.