In situ photopolymerization of dimethacrylamide

A dimethacrylamide was synthesized and used to formulate with the selected (meth)acrylates to form the in situ photocureable resins and composites. The effects of the selected comonomers with different functional groups on polymerization rate, degree of conversion, gel time, and compressive strength were investigated. The results show that in situ photopolymerization of the synthesized dimethacrylamide with comonomers having an electron-withdrawing and/or acrylate group dramatically increased the polymerization rate, degree of conversion, and compressive strength. On the other hand, an electron-donating group on either carbon-carbon double bond or ester linkage slowed down the polymerization. In contrast, the triethylene glycol dimethacrylate-based system did not show a clear pattern. The synergistic effect of the strong hydrogen-bonding between dimethacrylamide and organic acid groups may be responsible for higher compressive strengths. The formed composites showed the similar trend in compressive strength to the corresponding resins. Within the limitation of this study, it seems that in situ photopolymerization of dimethacrylamide or diacrylamide can be greatly accelerated by copolymerization with monomers having electron-withdrawing and/or acrylate groups. The monomers with methacrylate group can significantly reduce the polymerization rate and degree of conversion