NEW SYNTHETIC APPROACH FOR THE SYNTHESIS OF LIQUID-CRYSTALLINE BLOCK AND GRAFT-COPOLYMERS

Liquid crystalline block; and graft copolymers were synthesized accord ing to the macroinitiator and macroinimer concept. For this purpose: s ide chain block copolymers (polytetrahydrofuran-b-polymethylmethacryla te), having liquid crystalline 4,4'-cyanobiphenyl blocks were prepared and characterized. Unlike the liquid-crystalline homopolymer with mes ogenic units in the side chain, all block and graft copolymers showed a smectic A mesophase. The transition temperatures are hardly affected by;the composition and molecular weight of the block copolymers.