Phase Transition and Liquid Crystalline Structures of Side-Chain Liquid Crystalline Polysiloxanes Containing Acetoyl Terminal Group.

Abstract

Side-chain liquid-crystalline polysiloxanes containing acetoyl terminal group, Poly [n- {4- (4- (acetoyl) phenoxycarbonyl) phenoxy}] alkoxyl methyl siloxane, were prepared with different spacer length (n=3〜6). Phase transition and fine structures of these polymers were investigated by DSC, polarizing optical microscope, and X-ray diffraction methods. Glass transition and clearing temperatures of PAS-n samples indicated odd-even effect. Smectic A phase was observed in each sample, and layered crystal were formed in PAS-5 and PAS-6. The unit cell of layered crystal of PAS-6 showed orthorhombic form with the lattice parameters a=0.79nm, b=0.54nm, c=2.70nm.