Development of a novel and benign emulsion paint binder from epoxidized soybean oil and dimethylol urea blend

To develop a novel emulsion paint binder, dimethylol urea (DMU) resin synthesized from low formaldehyde to urea stoichiometric ratio (2:1) was blended with epoxidized soybean oil (ESBO) with 2.56% oxirane oxygen and 67% iodine value conversion. ESBO/DMU blends were prepared by varying the amount of ESBO from 10–70%. The blends were analyzed for formaldehyde emission, viscosity, refractive index, turbidity, density, gelation time and solubility in water, while the blends’ films were analyzed for moisture uptake and melting point. Homogenous blends were obtained up to 50% ESBO/DMU blend, while FTIR analyses show reactive ESBO/DMU blend at optimum blending. Formaldehyde emission and moisture uptake were reduced in the blends’ film, while ESBO also act as plasticizer by introducing softness in the blends’ film. Comparison of the properties of 40% ESBO/DMU optimum blend with other reported binders shows its good potentials and its capability to compete in the coating industry.