Use of cuprous ion and metallic copper as initiators of aqueous vinyl polymerization

Cuprous chloride and copper powder (in acid media) initiate the aqueous polymerization of certain vinyl monomers such as methyl methacrylate, ethyl methacrylate, methacrylic acid and styrene but it fails in case of acrylonitrile, methyl acrylate, and acrylic acid under identical conditions. Catalyst exponent of this initiator (in acid aqueous media) with respect to methyl methacrylate is 0.38. Quantitative determination of end‐groups by dye techniques of the polymers obtained shows that about 2 hydroxyl end‐groups per chain are present under acidic conditions in presence of slight traces of oxygen but in rigorous absence of oxygen, very little OH end‐groups are found incorporated. The mechanism of initiation under different experimental condition is discussed.