Cinétiques de télomérisation, 4. Nouvelle méthode de détermination des constantes de transfert en catalyse radicalaire

For the determination of transfer constants C_T to the telogen in telomerization reactions started with free radicals we used three methods. The first one is the method of Mayo, the second one is based on the variation of the conversion degree of telogen to monomer and the last method requires the knowledge of the cumulated number-average degree of polymerization DP _n and monomer conversion α_M of the samples during the reaction. Verifications of the proposed laws are made for methacrylic acid telomerization with CCl₃Br and methyl methacrylate telomerization with benzenethiol as a telogen and 2,2′-azoisobutyronitrile as the initiator at 70°C. The transfer constant to CCl₃Br is ca. 0,03 and that to C₆H₅SH ca. 1,5.