Synthesis and characterization of UV curable flexible urethane acrylate polymers

UV-curable urethane acrylate systems do not contain VOCs during processing and offer a beneficial solution to reduce carbon footprint. Unlike traditional coating methods such as solvent-based and water-based coating techniques, UV-curable systems are diluted with acrylates, which are reactive solvents, and the diluent is joined to the polymer at the end of curing process. Polymers obtained with this method can achieve high cross-linking density and offer low-cost, environment-friendly solutions in a wide variety of applications with their high mechanical properties. UV-curable urethane acrylates can be formed with a variety of urethane oligomers and reactive diluents, and elastic coatings can also be obtained. In this study, high elasticity urethane acrylate films were obtained with UV curing technique to be used with flexible surfaces. The effects of the poliols and monomers used in the obtained films were examined and their contribution on the film properties were examined. Polypropylene glycol macro molecules with molecular weights of 1000, 2000, 4000 and 6000 were used in the synthesis of oligomers. Isophorone diisocyanate, 4,4'-methylene dicyclohexyl diisocyanate, hexamethylene diisocyanate, as diisocyanate part of urethane, were used. A comparison was made using hydroxy ethyl methacrylate and hydroxy ethyl acrylate as acrylation compounds. The effects of poliol, isocyanate and acrylation agent used in the oligomer structure in elastic urethane acrylate films with the synthesized oligomers and prepared UV-curable mixtures were examined and interpreted by viscosity, gel content tests and stress-strain tests. It is aimed to present a guiding study for material selection while preparing UV-curable urethane acrylate, which can be used in coating elastic surfaces such as textiles.