Synthesis and characterization of hyperbranched aromatic polyester-imides with good thermal properties based on 1,3,5-tris(3′,4′-carboxyphenyl) benzene trianhydride

A new trifunctional monomer, 1,3,5-tris(3',4'-carboxyphenyl)benzene trianhydride (TAn), was synthesized and characterized by elemental analysis, FTIR, H-1 and C-13 NMR spectroscopy. Subsequently, one-step high-temperature polymerization of TAn and a series of commercially available diamine monomers such as p-phenylenediamine (PDA, 1), 4,4'-oxydianiline (ODA, 2), and 1,5-diaminonaphthalene (DAN, 3) successfully yielded wholly aromatic anhydride-terminated hyperbranched poly(ester-imide)s HBPEI 1, 2, and 3, respectively. Gelation was effectively avoided by controlling 1:1 M ratio of A(2) and B-3 monomers and maintaining total solid content 10 mmol, thereby, producing a novel family of aromatic HBPEIs with inherent viscosities (eta(inh)) of 0.17-0.28 dL/g. As-prepared HBPEIs were fully characterized by FTIR spectroscopy and were soluble in DMAc, DMSO and NMP. Degree of branching (DB) by H-1 NMR analysis of the HBPEIs was estimated to be 0.52-0.56. Differential scanning calorimetry (DSC) showed glass transition temperatures (T-g) between 198 and 208 degrees C and the synthesized polymers were thermally stable. Furthermore, crystallinity of the polymers was evaluated by means of X-ray diffraction patterns. (C) 2010 Elsevier Ltd. All rights reserved.