KINETIC INVESTIGATIONS ON THE PHOTOPOLYMERIZATION OF DIFUNCTIONAL ANDTETRAFUNCTIONAL METHACRYLIC MONOMERS IN POLYMERIC MATRICES - ESR AND CALORIMETRIC STUDIES - II - POSTPOLYMERIZATION REACTIONS

The reaction kinetics in the dark of photopolymerized mono- and dimeth acrylates in a polymeric binder has been studied. Electron spin resona nce spectroscopy (ESR) provided useful information regarding the natur e of the radicals involved in postpolymerization reactions. Computer s imulations were performed to study the decay of the propagating radica ls by considering normal bimolecular termination and transfer reaction s of the radicals to the binder. Differences were found in the termina tion reactions for mono- and difunctional monomers when they were phot opolymerized in a solid medium. Absolute kinetic constants for H-trans fer reaction with the binder, relative kinetic rate constants for radi cal-radical coupling, and average lifetimes for the radicals have been calculated. (C) 1998 John Wiley & Sons, Inc.