Abstract: A process for phosphonylating the surface of an organic polymeric preform and the surface-phosphonylated preforms produced thereby are provided. Organic polymeric preforms made from various polymers including polyethylene, polyetheretherketone, polypropylene, polymethylmethacrylate, polyamides, and polyester, and formed into blocks, films, and fibers may have their surfaces phosphonylated according to the present inventive process. The process involves the use of a solvent that does not dissolve the organic polymeric preform but does dissolve a phosphorus halide such as phosphorus trichloride. The solvent chosen must also be nonreactive with the phosphorus halide. Such solvents available for use in the present process include the fully-halogenated liquid solvents such as carbon tetrachloride, carbon tetrabromide, and the like.