Resol was solution-blended with vinyl acetate-2-ethylhexyl acrylate (VAc-EHA) resin in an aqueous medium, in varying weight fractions, with hexamethoxymethylmelamine (HMMM) as a crosslinker and the data were compared with a control. The present work was aimed to obtain an optimum combination of high-temperature resistance by synthesis of an interpenetrating network (IPN) of the resins. The control gave a semi-IPN system, in which the resol crosslinked, while the acrylic did not, whereas the blend, where HMMM was the crosslinker, gave a full-IPN system. FTIR spectra of the blends of resol/VAc-EHA/HMMM indicated the formation of new stretching, which was generated due to crosslinking reactions among VAc-EHA and the crosslinker HMMM. TGA showed that, with an increase in the VAc-EHA percent in semi-IPNs, the decomposition temperature decreased gradually, whereas in case of full-IPNs, the decomposition temperature increased with increase in the VAc-EHA percent. However, the full-IPNs had a higher decomposition temperature than that of the semi-IPNs, at the same resol/(VAc-EHA) ratio. © 2002 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 86.