SYNTHESIS AND ELECTROOPTICAL BEHAVIOR OF A NEW CHIRAL SMECTIC SIDE-CHAIN POLYSILOXANE

A new chiral side-chain polymer was prepared by hydrosilylation of a d imethylsilane-methylhydrosilane copolymer. The chiral group of the mes ogenic side-chain was (+)2-chloro--3-(3-nitro-4-hydroxyphenyl)propioni c acid butyl ester while the main part of the aromatic nucleus consist ed of 4'-hydroxybiphenyl-4-carboxylic acid. Phase behaviour was studie d by DSC and polarizing microscopy, and correlated with dielectric mea surements. Alignment properties and ferroelectricity were studied in c ells with surface-induced alignment and in shear cells. The polymer ex hibits chiral C-and A-phases. The spontaneous polarization is 130 nC/c m2 at 60-degrees-C and the polymer shows ferroelectric switching at ro om temperature.