Methods for producing elastomers or elastomeric compositions are provided. One or more C4 to C7 isoolefins and one or more comonomers can be polymerized in the presence of a diluent comprising one or more hydrofluorocarbons to provide a slurry comprising polymer product, unreacted monomer and the diluent. The slurry can be extruded to separate at least a portion of the diluent from the polymer product. The separated diluent can be recycled for polymerizing the one or more C4 to C7 isoolefins.