A dielectric constant method of following the non-stationary state in polymerization - III. The determination of rates of polymerization and of radical lifetimes

This method has been applied to the polymerization of styrene, vinyl acetate, methyl acrylate and butyl acrylate, initiated both by continuous illumination and by use of a flash discharge tube. It has proved possible to delineate the course of the non-stationary state with continuous illumination and also to delineate the decay of radical concentration when illumination ceases. With the flash the decay of radical concentration can be delineated. The analysis of these records gives the values of the lifetimes of the radicals and the corresponding rates of polymerization. These lifetimes agree reasonably with those determined by other methods. The general application of this method and of the instrument to other problems in physical chemistry is indicated.