Andre Lantz

Etude de la télomérisation de C2F4 avec les iodures de perfluoroalkyle Partie I. Télomérisation radicalaire

Abstract The remomerization of C 2 F 4 with C 6 F 13 F by various initiators has been achieved. These results have shown the effect of the temperature on the mechanism of the reaction. With t -butylperoxide (DTBP) at 130°C, we have observed that the apparent relative reactivity of C 8 F 17 I (monoadduct) is constant versus time. On the contrary, with cyclohexyl percarbonate(CHPC) at 47°C, it decreases continuously. On the other hand the ratio of the initial rates of consumption of monomer to telogen is close to 1 at high temperature while it is near to 2 at low temperature. These results clearly demonstrate that the mechanism proceeds by monoaddition in the first case (DTBP) while it is by propagation in the second case (CHPC). Secondly, we have proposed a mathematical simulation of these two kinds of reaction and discussed the validity of these laws.

Telomerisation du tetrafluoroethylene avec le tetrachlorure de carbone par catalyse redox

Abstract The redox telomerization of tetrafluoroethylene with carbon tetrachloride using the FeCl3/benzoīn complex as catalyst has been studied. The CnFe transfer constants of this reaction are measured and compared to the results obtained under other conditions, especially under radical catalysis. We can also evaluate the Ki constant of the reaction rate between telogen and the metal at its lowest oxidation state. The DP n on the reaction conditions, the structure of low molecular weight telomers being established by mass spectrometry and the conditions to obtain the telomers of C2F4 with CCl4 are specified.