Fluorination of nitrile-butadiene rubber without gelation via radical graft polymerization in presence of chain transfer agent

Fluorination could efficiently improve the comprehensive performance of nitrile-butadiene rubber (NBR). However, severe gelation usually occurred in the radical graft polymerization onto the diene-based polymers. Here, a facile approach has been established for the facile fluorination of NBR without gelation via radical graft polymerization in presence of n -dodecylmercaptan (NDM) as chain transfer agent, with 2,2,3,4,4,4-hexafluorobutyl acrylate (F6) as the model fluorinating monomer. The gel content decreased with increasing the feeding ratio of NDM and reached 0 with a feeding ratio of NDM of 50 mol% of the initiator, with a fluorination degree of 0.50%. The graft polymerization mechanism was proposed with the 1 H NMR analysis. The proposed strategy is expected to provide a promising approach for the functionalization of diene-based polymers.