Effect of humidity on curing of alkoxysilane-functionalized alkyd coatings

The effect of relative humidity on the curing of alkoxysilane functional alkyds and reactive diluents was evaluated. Alkoxysilane functional alkyds and tung oil-based reactive diluents were synthesized and used as additives in varying amounts in alkyd coatings. Looking at modified alkyd versus modified reactive diluent allows for the comparison of the humidity effect on high and low molecular weight alkoxysilane functional additives. The coatings were cured at 25 and 75% relative humidity and evaluated for drying time, coating and tensile properties, and gel content. It was found that at higher humidity, the alkoxysilane-containing samples improved properties significantly when compared to the control alkyd.