Synthesis and characterization of aliphatic-aromatic hyperbranched polyesters with high organosolubility

Carboxyl-terminated, water soluble, hyperbranched polyesters (HBPET) with aliphatic-aromatic structure were synthesized at three different monomer mole ratios (A(3)/B-3 = 1: 1, 2: 1, 1: 2, respectively) by melt polycondensation of aconitic acid and phloroglucinol via A(3)+ B-3 approach. Fourier transform infrared (FTIR) spectroscopy indicated as that was expected HBPET, which showed excellent solubility in a variety of polar solvents such as N,N-dimethyl formamide (DMF), N-methyl-2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and tetrahydrofuran (THF). The weight-average molecular weight of HBPET ranged from 7792 to 9214 g mol(-1) and their intrinsic viscosity were varied from 0.17 to 0.34 dL g(-1). The degree of branching of the HBPET was estimated to be 0.44-0.49 by H-1 and C-13 NMR measurement. The thermogravimetric analysis (TGA) measurement revealed that HBPET was of 10% weight-loss at 340A degrees C in N-2.