A rigid-body pendulum rheometer was used to observe the isothermal cure behavior of an anionic poly(urethane urea) dispersion crosslinked with different amounts of partially methylated melamine formaldehyde (PMMF). In this experiment, the anionic poly(urethane urea) dispersion had a large number of > N-H crosslinking or branching sites in urethane and urea groups per molecule, which allowed a large amount of PMMF to couple witli the elastic polyurethane (PU) backbone. The test results showed that the cure response of the PU dispersion crosslinked with PMMF was a function of the concentration of PMMF and indicated that 30 phr PMMT could be the optimum amount of the crosslinking agent and that 120 degrees C was the optimum temperature for the curing pro-cess. In addition, PMMF self-condensation could take place during the curing process. The self-condensation of PMMF also was monitored by a thermogravimetric method. Moreover, the dynamic mechanical properties of PMMF-crosslinked PU films were affected by the concentration of PMMF. From the Curing behavior and dynamic mechanical analysis test results, it was reasonable to assume that highly PMMF branched PUs with partial crosslinking structures could be formed. (c) 2007 Wiley Periodicals, Inc.