Novel soy-based thiols and enes were synthesized and characterized, soy-based thiol-ene UV curable coatings were formulated and their coating physiochemical properties were characterized in detail. Utilization of biorenewable resources in the environmentally friendly UV curable technology provides a "green+green" solution to the stricter regulations in coatings industry. Novel soy-based thiols and enes were synthesized through Lewis acid catalyzed ring opening reaction of the epoxidized soybean oil by multifunctional thiols or hydroxyl functional allyl compounds. FTIR confirmed the formation of the desired target compound. The soy-based thiols and enes were formulated with petrochemical based enes and thiols respectively to make thiol-ene UV curable coatings. Typical coating film properties, thermal properties and photopolymerization kinetics of these coatings were examined. Soy-based thiol-ene coatings with lower functionality have poor UV curability and coating properties due to lower crosslink density. Soy-based thiols and enes with higher functionality can be UV cured in combination of petrochemical based enes or thiols even without the presence of free radical photoinitiators. Better coating film properties were obtained from these higher functionality thiol-ene systems toughened by hyperbranched acryalates.
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