Synthesis of water-soluble tetrafunctional urethane acrylate bearing a pentaerythritol core and its radical polymerization behaviors in an aqueous solution

A novel water-soluble tetrafunctional urethane acrylate (TUA) was successfully synthesized by addition reaction of pentaerythritol to 2-isocyanatoethyl acrylate. TUA efficiently underwent radical polymerization and its copolymerization with monofunctional acrylate monomers exhibiting hydrophilicity in an ethanol aqueous solution, affording corresponding networked polymers in high yields. Notably, TUA exhibited much lower volume shrinkage during the radical polymerization compared to a comparative pentaerythritol core based tetrafunctional acrylate containing no urethane bonds. The thermal decomposition temperature of the networked homopolymer, synthesized from TUA, was much higher than those of the linear polymers, synthesized from monofunctional urethane acrylate monomers. TUA is expected to be applied to the development of environmentally sustainable polymer materials.