The effects of initiator and diluent on the photopolymerization of 2-hydroxyethyl methacrylate and on properties of hydrogels obtained

A variety of photo-initiators and water-soluble diluents were used to study the photopolymerization of 2-hydroxyethyl methacrylate (HEMA). The rate of polymerization can be correlated to the structures as well as the concentration of initiators and diluents. It was found that, in terms of rate of polymerization, 2,2-dimethoxy-2-phenyl acetophenone and glycerine were the best initiator and the best diluent among all initiators and diluents evaluated. The rate of polymerization was found to have a great impact on mechanical properties, while it showed only minor effects on water contents of hydrogels derived from HEMA.