Synthesis, characterization, and processing of aromatic copolyesters with different monomer sequences

Two aromatic copoyester compositions were prepared from p‐hydroxybenzoic acid, hydroquinone, and isophthalic acid with compositions 2 : 1 : 1 (HIQ50) and 1 : 1 : 1 (HIQ33). For each of these compositions, one random copolyester and one known sequence copolymer was prepared. The random compositions were prepared by melt condensation, whereas controlled sequence polymers were prepared by low‐temperature solution polymerization. For the 1 : 1 : 1 composition, the controlled sequence polymer had higher crystallinity than that of the random, whereas the 2 : 1 : 1 composition random copolymer had higher crystallinity. The difference in crystallinity is attributed to the sequence distributions in the copolymers. All compositions were thermotropic in nature. © 1994 John Wiley & Sons, Inc.