Synthesis and Characterization of Low Viscosity Aromatic Hyperbranched Poly(trimellitic anhydride ethylene glycol) Ester Epoxy Resin

Abstract From carboxyl‐ended hyperbranched poly(trimellitic anhydride ethylene glycol) ester (HTM) and epichlorohydrin, low viscosity (1 000–1 250 cp) aromatic HTM epoxy resin (HTME) was synthesized. Molar mass of the HTM was calculated from its acid value with a “Recursive Probability Approach”, and its degree of branching (0.63–0.70) was characterized by model compounds and 1 H NMR‐minus spectrum technology. HTME has an epoxy equivalent weight of <470 g/mol; it is an ellipsoid‐like molecule with a size of <8.65 nm. This low viscosity novel epoxy resin has important applications in the field of “no‐solvent” coatings. magnified image