Dethiocarboxylation of MADIX (co)polymers

Abstract : One potential drawback of the MADIX process lies in the fact that the xanthate terminal group, if not deactivated, is likely to be degraded during the lifetime of the polymer or under some specific application conditions. Several appropriate treatments were developed in order to prevent an uncontrolled degradation over time which may eventually generate low molecular weight malodorous, potentially toxic sulfur-based by-products. For instance, thermally-induced elimination of xanthate terminal groups of polymer chains (Chugaev reaction) was efficiently conducted with five different secondary xanthates. This allowed the generation of thiol groups at the end of PDMS and MADIX polymer chains.