Polymerization of Bisacrylic Monomers within a Liquid-Crystalline Smectic B Solvent

Abstract

A smectic B (S,) solvent may provide a very highly ordered, and possibly oriented, host medium for polymerization processes. Photochemical polymerizations of two bisacrylic monomers were therefore carried out in a S_B medium. The process conditions were chosen on the basis of a preliminary study of the monomer-solvent binary system carried out by differential scanning calorimetry (D.S.C.), optical microscopy and X-ray diffraction. The polymerization was then studied by D.S.C. at different reaction times. These measurements showed clearly that there is a point along the reaction path at which the growing polymer chains start segregating from the solvent and the mesomorphic bulk no longer acts as a reaction solvent but only as a reservoir for the ponomer. The polymer chains from that point keep growing only upon or between the faces of the S_B layers. Electron microscopy observations showed that the morphology of the final polymer is affected by this interlayer process.