Photoinitiation of Acrylates Via Sensitized Phthalimide Derivatives

When isopropylthioxanthone is used as a coinitiator for substituted N-phenylphthalimide photoinitiators, rapid rates of acrylate polymerization are attained if a tertiary amine is present as a hydrogen source. N-Phenylphthalimide with electron withdrawing substituents on the N-phenyl ring in the presence of a combination of isopropylthioxanthone and N-methyl-N,N-diethanolamine results in an increase in the maximum rate of polymerization of 1,6-hexanedioldiacrylate by a factor of as much as twice that attained when only the coinitiator and N-methyl-N,N-diethanolamine are present