Chain Propagation in UV Curing of Di(meth)acrylates

Abstract

Novel difunctional (meth)acrylates that are thermally degradable were designed and synthesized to study the kinetic chain length of the UV cured resins. These monomers have both hemiacetal ester moiety as a degradable unit and acrylate or methacrylate unit as a polymerizable unit. The UV curing property of these monomers was studied under N2 atmosphere. A linear polymer, i.e., poly(methacrylic acid) or poly(acrylic acid), was obtained by the thermal degradation of the UV cured resins. Poly(methacrylic acid) and poly(acrylic acid) were converted to poly(methyl methacrylate) and poly(methyl acrylate), respectively, by treating with a diazomethane reagent. To obtain the kinetic chain length for the photopolymerization of difunctional (meth)acrylates, we performed size exclusion chromatography. It was shown that the kinetic chain length of the UV cured resins was affected by the monomer structure, concentration of initiator, exposure dose intensity, and conversion. Furthermore, the kinetic chain length for th...