Free Radical Polymerization Kinetics of Hindered Monomers

The primary aim of this project is to investigate the mechanisms of propagation, termination and transfer in vinyl monomers with 1,1- or 1,2-disubstitution where the substituents are bulky and exercise a significant entropic barrier to free radical reactions. The significance of the proposed program lies in the determination of kinetic parameters for hindered monomers, which should provide considerable insight into the mechanisms of free radical polymerization. Polymerization kinetics of the hindered monomers will be investigated by means of Pulsed-Laser Polymerization (PLP) and subsequent analysis of the chain length distribution by Size-Exclusion Chromatography. Besides the well known PLP method new techniques for the determination of the kinetic parameters - especially developed for hindered monomers - will be used. In addition, new living/controlled polymerization techniques will be utilized to get deeper insight into the mechanism of the polymerization of hindered monomers. Especially the kinetics of the termination reaction of hindered monomers is still far from being understood in depth and has to be investigated in detail. This project will try to elucidate the reaction mechanisms of the free radical polymerization, which has many advantages for chemical industries as it is robust, versatile and relatively insensitive to impurities.