Polymerization of vinylphosphonium compounds

Abstract

AbstractThe mechanism of the ionizing radiation‐initiated polymerization of aqueous solutions of tributylvinylphosphonium bromide (TBVPB) to high molecular weight polymers was established to be free radical. Similar polymerization was observed in acetone, acetonitrile, and acetic acid. The failure of even high radiation doses to induce the polymerization of TBVPB when in chlorobenzene solution was explained on the basis of the interaction of chlorine atoms with bromide ions. Triethylvinylphosphonium bromide, tricyclohexylvinylphosphonium bromide, and dimethylphenylvinylphosphonium bromide gave little or no polymer using conditions which polymerized TBVPB almost completely. Conventional oxidizing peroxidic free radical catalysts failed to initiate the polymerization of TBVPB. Nonoxidizing materials like di‐tert‐butyl peroxide and azo compounds did catalyze the polymerization to give high molecular weight polymers. Apparently the oxidizing peroxides are quickly reduced by the bromide ion before any homolytic cleavage can occur. Tributylvinylphosphonium chloride was polymerized in aqueous solution using potassium persulfate, the homolytic cleavage of persulfate competing favorably with redox processes involving the chloride ion. Copolymerization of TBVPB with a series of common monomers resulted in copolymers containing varying amounts of phosphorus in the expected order.