Aliphatic-aromatic copolyesters containing phosphorous cyclic bulky groups

A series of phosphorus-containing copolyesters was prepared by polycondensation of 2-(6-oxido-6H-dibenz < c,e >< 1,2 > oxaphosphorin-6-yl)-1,4-naphthalene diol, 1, or of an equimolecular amount of I and different aliphatic diols 2, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,12-dodecanediol, with an aromatic diacid chloride containing two preformed ester groups 3, namely terephthaloyl-bis-(4-oxybenzoyl-chloride). The copolyesters exhibited good thermal stability having the decomposition temperature above 375 degrees C. The glass transition temperature was in the range of 96146 146 degrees C. The polymers exhibited thermotropic liquid crystalline behavior, as was observed with polarized optical microscopy. DSC and X-ray experiments were also found. in concordance with mesophase formation. (C) 2009 Elsevier Ltd. All rights reserved.