Hyperbranched Aromatic Polyesters

Summary: Having developed a theoretical model of hyperbranched polymerization involving AB 2 and B 2 monomers we present preliminary results of a test of its validity for the system consisting of 4,4‐bis(4‐hydroxyphenyl)pentanoic acid (AB 2 monomer) and bisphenol A (B 2 monomer). The monomers reacted at room temperature to yield the title hyperbranched polyesters. Diisopropylcarbodiimide (condensation water remover) along with an effective catalyst were used for that purpose. The total of AB 2 monomer was introduced at once to a reactor containing B 2 core monomer or it was divided into 3 or 5 equal portions and each of them introduced after the monomers previously present have reacted to a predetermined conversion. GPC measurements of the resulting molecular mass distribution gave inconclusive results because of poor reproducibility of polymer isolation/purification procedure and/or insufficient accuracy of GPC technique.