SYNTHESIS, CHARACTERIZATION, AND PROCESSING OF AROMATIC COPOLYESTERS WITH DIFFERENT MONOMER SEQUENCES

Two aromatic copoyester compositions were prepared from p-hydroxybenzo ic acid, hydroquinone, and isophthalic acid with compositions 2 : 1 : 1 (HIQ50) and 1 : 1 : 1 (HIQ33). For each of these compositions, one r andom copolyester and one known sequence copolymer was prepared. The r andom compositions were prepared by melt condensation, whereas control led sequence polymers were prepared by low-temperature solution polyme rization. For the 1 : 1 : 1 composition, the controlled sequence polym er had higher crystallinity than that of the random, whereas the 2 : 1 : 1 composition random copolymer had higher crystallinity. The differ ence in crystallinity is attributed to the sequence distributions in t he copolymers. All compositions were thermotropic in nature. (C) 1994 John Wiley & Sons, Inc.