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

For the determination of transfer constants CT 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 DPn and monomer conversion αM 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.