Enhancing the performance and revealing the thermal behavior of the water-based coating derived from waterborne alkyd resins and totally methyl etherified amino resins

In this study, the curing parameters of the water-based coating were carefully optimized using waterborne alkyd resins as the matrix resin and totally methyl etherified amino resins as the crosslinking agent. Through an orthogonal experimental design and a controlled experiment, the optimal conditions, which were a 7:1 ratio of alkyd resins to amino resins and curing at 403.15 K for 30 min, were determined. Droplet size distribution and zeta potential measurements confirmed that the composite resin emulsion prepared with the optimal ratio was more uniformly and stably dispersed in water, which helped to optimize the coating and make it have excellent physical properties, mechanical stability and chemical durability. Thermal stability was also thoroughly evaluated by TGA analysis, paying particular attention to the third degradation stage of the optimized composite resin coating (573.15-733.15 K), pyrolysis kinetic analysis provided deeper insights into its thermal behavior. Activation energies calculated through both the KSA and Starink methods exhibited consistent values of 195.47 kJ/ mol and 196.06 kJ/mol, respectively. Furthermore, a reaction mechanism function of G(alpha) = [- ln(1-alpha)]3 via C-R method implying a sigmoidal rate equation or stochastic nucleation. The activation energy calculated by this method is 211.10 kJ/mol and the pre-exponential factor is 2.22 x 1016 min- 1. Notably, the thermodynamic parameters obtained from all three methods show remarkable agreement.