Kinetic studies on the telomerization and polymerization of vinyl chloride

Abstract

The photochemical reaction between brornotrichloromethane (TBr) and vinyl chloride (VC) has been studied over a wide range of reactant concentrations varying from 0.087 to 9.24 mole 1.-1 for TBr and from 1.26 to 14.4 mole 1.-1 for VC. The products of the reaction vary from the 1 : 1 adduct to low molecular weight polymer. Under the conditions studied, the reactions proceed by radical chain processes. When TBr is in excess, the addition of trichloromethyl radicals to VC is the rate-determining step, and the velocity coefficient for this reaction at 25°C was 990-1950

ESR observation of propagating radical and estimation of propagation rate constant in the radical polymerization of vinyl chloride

“…[3][4][5] They are 6 200, [3] 3 130 (25 8C), [4] and 11 000 M -1 N s -1 (25 8C) [5] which seem to be too deviated to choose which value is the best value. It seems to be necessary to estimate the k p value by other methods such as Pulse Laser Polymerization (PLP) method [18][19][20] or ESR method, if possible.…”

“…Oligomer formation suggests a difficulty of estimation of the k p value in this case. However, Bengough et al [3] shows that the k p value was not dependent of chain length by the estimation of k p by rotating sector method. The agreement of our k p values with Bengough's data seem to be reasonable, if this is true.…”

“…[2] However, kinetic data such as the propagation rate constant (k p ) are insufficient even at the present time. Three papers have been reported so far on the k p value for vinyl chloride, which has been estimated to be 3 130, [3] 6 200, [4] and 11 000 [5] M -1 N s -1 at 25 8C, respectively, by the rotating sector method. The deviation of the k p values may be ascribable to the systematic error which is involved in application of the rotating sector method to the complicated polymerization system such as vinyl chloride.…”

Search for highly resolved electron spin resonance spectra of the transient radical in radical polymerization

“…However, it was in agreement within the experimental error with one of those obtained by the rotating sector method. 52 Therefore, it is listed as a tentative datum in Table I.…”