A modified synthesis of liquid-crystalline poly(ethylene terephthalate-co-oxybenzoate)s with completely random chain structure

A new method for synthesis of liquid‐crystalline poly(ethylene terephthalate‐co‐oxybenzoate)s (PET/HBA) is proposed. In order to prevent formation of PET‐rich phases, complex monomers were used instead of PET. In comparison tc copolyesters synthesized conventionally, the new products proved to be much more homogeneous. 13C NMR measurements evidenced that the chain segment distribution is almost random. In contrast to literature data for a copolyester composition of PET/HBA (50/50 mol/mol) only a single glass transition was detected by dynamic mechanical analysis. The influence of transesterification reactions on the homogeneity is discussed.