Abstract
Linear poly(1,3-cyclohexadiene) (PCHD) with different molecular weights and microstructures were fluorinated with difluorocarbene (:CF2) generated in situ. Polymers having a unique structure, in which a fluorine-containing three-membered ring is connected directly to a six-membered cyclic backbone, were generated. Various reaction conditions such as concentration of inhibitor, concentration of the reactants, reaction time, etc., were examined to elucidate their effect on the efficacy of fluorination and the extent of side reactions. Fluorination enhances the thermal stability of PCHD and dramatically increases its glass transition temperature to the highest Tg among all fluorinated polydienes. Fluorination reduces the level of unsaturation and widens the range of potential applications of PCHD by improving its thermal and chemical stability. We believe that fluorinated and sulfonated copolymers based upon PCHD have potential utility as fuel cell proton exchange membranes.