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Alkyds are essentially oil modified polyesters derived from oils, dibasic acids and polyols. Being bio-renewable, versatile and low-cost made alkyds one of the most consumed coating material in the world. The slow autoxidative drying of a conventional alkyd formulation has limited the potential application for alkyds. Silicone additives are usually used in the hybrid coating formulations to get better anticorrosion property via sol-gel structure. In the meantime, high crosslink density from UV curing and sol-gel structure can give the coating films great resistance properties compared to conventional alkyds, especially anticorrosion property.This thesis is focused on the development of anticorrosion UV curable alkyd coating systems with fasting curing speed and competitive coating properties. Two UV-curable alkyd resins were synthesized by functionalizing conventional medium linseed oil alkyd with acrylate and methacrylate functional groups. Two compatible silicone additives were prepolymerized as VTMS colloid and TEOS oligomer. The chemical structures were characterized using 1H NMR, MALDI mass spectrometry, and FTIR. UV curing kinetics of UV curable alkyd systems with 0-20 wt% silicone additives were investigated with real-time FTIR and photo DSC. General coating properties were characterized including pendulum hardness, pencil hardness, impact resistance, cross hatch adhesion, pull off adhesion, and MEK double rub. To improve the enhance of anticorrosion property of modified UV curable coatings, salt spray test was used to evaluate the hybrid coatings. |
