This invention relates to methods of making graft copolymers, and articles having such graft copolymers. The methods may provide better control than in radicalization or photoinitiated polymerization techniques. For example, a graft copolymer can be prepared by reacting an alkoxide ion with a polymer. The alkoxide, in turn, can be provided by any suitable technique, for example, by reacting an alcohol with a base. In some embodiments of the invention, the graft copolymers may be a normally hydrophobic polymer, such as a polysulfone, that has been made more hydrophilic due to the attachment of hydrophilic side groups such as polyethylene glycol or polypropylene glycol. The copolymers of the invention have many uses, for example, in films or porous membranes.