Manufacturing and photocrosslinking of a new bio‐based dimethacrylate resulting in hydrophobic crosslinked films

A new bio-based dimethacrylate (EMHO) consisting of three isomers, that is (ethane-1,2-diyl-bis(9-methacryloyloxy-10-hydroxy octadecanoate) [EMHO-i1], ethane-1,2-diyl-9-hydroxy-10-methacryloyloxy-9′-methacryloyloxy-10′-hydroxy octadecanoate [EMHO-i2], and ethane-1,2-diyl-bis(9-hydroxy-10-methacryloyloxy [EMHO-i3]), was made by a three-step reaction starting from esterification oleic acid with ethylene glycol followed epoxidation in second step, epoxy ring-opening methacrylic third step. The obtained photocured applying ultra-violet technology to receive neat polymer on the one hand presence further methacrylate, such as 4-(4-methacryloyloxyphenyl)-butan-2-one (MAPO) or methyl 9-(1H-imidazol-1-yl)-10-(methacryloyloxy)-octadecanoate 9-(methacryloyloxy)-10-(1H-imidazol-1-yl)-octadecenoate available isomer mixture (MIMAO), other hand. photopolymerization kinetic study photo-differential scanning calorimetry showed addition MAPO MIMAO during photocuring resulted an increase both polymerization rate final conversion monomer comparison homopolymerization EMHO. As expected, network density elastic modulus copolymers reduced compared homopolymer caused methacrylate comprising only polymerizable functional group. crosslinked films contain high gel content. Those using excess glass transition above room temperature aromatic ring MAPO. High contact angle values for water indicate hydrophobicity attributed long alkyl chains contained dimethacrylate. copolymer may be interesting application water-repellent coating surface protection against corrosion.