Ewa Andrzejewska1, Gordon L. Hug2, Maciej Andrzejewski1, Bronisław Marciniak3
1 Institute of Chemical Technology and Engineering, Poznan University of Technology, M. Curie-Sklodowskiej 2, 60-965 Poznan, Poland,
2 Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA,
3 Faculty of Chemistry, A. Mickiewicz University, 6 Grunwaldzka Str., 60-780 Poznan, Poland
This work was presented at the Workshop on Reactive Intermediates in Sulfur Chemistry (Poznań, 1998). It is a summary of earlier investigations on the role of cyclic sulfides (1,3,5-trithiane derivatives) in accelerating the initiation of polymerization induced by benzophenone (BP). The primary photochemical reactions between BP and trithianes were followed by nanosecond laser flash photolysis. Tripletquenching rate constants and quantum yields for electrontransfer products and ketyl-radical formation were measured. Photoinduced polymerizations with model monomers initiated by BP/trithiane couples were followed by isothermal differential scanning calorimetry (DSC). The kinetics of these polymerizations were compared with the photochemical information on the quenching of excited BP by the trihianes. The polymerization efficiency using the various coinitiators did not follow the efficiency of photo-induced formation of the initiating radicals. The reasons for this lack of correlation were discussed in terms of the various factors that influence the polymerization aside from the efficiency of radical formation.