Segmented liquid-crystalline polyesters with allyl groups as lateral substituents. Synthesis and characterization

The synthesis and the characterization of segmented liquid-crystalline [P(n )] made by interfacial polycondensation of 3-allyl-4,4'-dihydroxybiphenyl a nd the acid chlorides of alpha,omega-dicarboxy-alkanes are reported. The fl exible spacers contain even numbers of methylene units (n = 6-14), All poly mers are enantiotropic showing a nematic phase with isotropization temperat ure in the range of about 95-175 degrees C. At room temperature all polymer s show a mesophasic structure except for P(8) which is crystalline. Both P( 12) and P(14) show a quasihexagonal phase with six chains per unit cell. (C ) 2000 Elsevier Science Ltd. All rights reserved.