Synthesis and characterization of hyperbranched aromatic poly(ester–imide)s

The synthesis and characterization of hyperbranched aromatic poly(ester–imide)s are described. A variety of AB2 monomers, N-[3- or 4-bis(4-acetoxyphenyl)toluoyl]-4-carboxyl-phthalimide and N-{3- or 4-[1,1-bis(4-acetooxyphenyl)]ethylphenyl}-4-carboxy phthalimides were prepared starting from condensation of nitrobenzaldehydes or nitroacetophenones with phenol and used for synthesis of hyperbranched poly(ester–imide)s containing terminal acetyl groups by transesterification reaction. These hyperbranched poly(ester–imide)s were produced with weight-average molecular weight of up to 6.87 g/mol. Analysis of 1H NMR and 13C NMR spectroscopy revealed the structure of the four hyperbranched poly(ester–imide)s. These hyperbranched poly(ester–imide)s exhibited excellent solubility in a variety of solvents such as N,N-dimethylacetamide, dimethyl sulfoxide, and tetrahydrofuran and showed glass-transition temperatures between 217 and 255 °C. The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperature (Td10) ranging from 365 to 416 °C in nitrogen.