Abstract
The synthesis and the phase behaviour of three laterally substituted stiff-chain polymers containing 2-phenylbenzoxazole units is reported. Polymers were obtained by reaction of 2-(4-acetoxyphenyl)-6-acetoxybenzoxazole with 2-phenoxyterephthalic acid (polymer 2a), 2-phenylthioterephthalic acid (polymer 2b) and 2-hexadecylthioterephthalic acid (polymer 2c). Polymers 2a and 2b are virtually non-crystalline. 2a is nematogenic, while for 2b a smectic-like liquidcrystal phase is observed, whose structural periodicity is probably connected with the intercalated stacking of the lateral phenyl groups along the direction of the chain axes. The solid phase of 2c is of the sanidic type. On melting, a liquid-crystal phase with equatorial periodicity is observed. This periodicity is probably related to the segregation of the stiff chains between the paraffinic layers.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
