Determination of the Velocity Constants in the Polymerization of Vinyl Compounds

Abstract

THE accepted mechanism for the polymerization of vinyl compounds involves four velocity constants: initiation (k₁), chain propagation (k₂), chain transfer (k₃), and termination (k₄). It is well known that standard methods of investigation give only two relations for the determination of these coefficients. In the absence of any transfer reaction, these relations determine k₁ and one of the ratios k₂/k₄, k₂/k₄^1/2.according to the order of the termination reaction. Melville¹ has recently described a method which provides another relation between the velocity constants, and hence allows their absolute values to be calculated under conditions such that transfer is unimportant.