Compositional heterogeneity and molecular weight distribution of copolymer systems, 2. Kinetics of free‐radical grafting and heterogeneity of its product

The heterogeneity of graft copolymers was interpreted on the basis of the kinetics of free‐radical grafting under the conditions in which grafting was expected to be random. Besides some well‐known kinetic equations, a new equation relating the rate of graft‐chain production with the initiator, monomer, and prepolymer concentrations was derived. The theory was applied to analyze Cameron's data on the benzoyl peroxide initiated styrene grafting onto polybutadiene in benzene. It was found that the theory quantitatively describes the experimental results. Also an equation relating the graft fraction with the prepolymer and monomer concentrations under the conditions in which terminations were dominated by disproportionation was proposed.