APPLICATIONS OF ESR TECHNIQUES TO THE STUDY OF FREE - RADICAL PROCESSES AND KINETICS IN ACRYLIC POLYMERIZATIONS

Electron spin resonance (ESR) techniques have been applied to a detail ed study of batch and semicontinuous emulsion polymerization of methyl methacrylate; butyl acrylate and styrene have been briefly studied. Q uenching of samples from the polymerization reactor followed by ESR an alysis are useful, but we have developed continuous flow techniques wh ich are preferable in many cases. ESR techniques can provide valuable information relating to the nature of free radical reactions, the conc entration of propagating free radicals, and the kinetic processes in t hese reactions. Direct ESR analysis is most valuable but is not applic able to all systems. Spin trapping techniques can be useful for system s not accessible by direct analysis.