A method for making modified poly(ethylene oxide) by graft polymerizing thereto organic monomers containing a trialkoxy silane functional group or a moiety that reacts with water to form a silanol group, such as methacryloxypropyl trimethoxy silane, onto the poly(ethylene oxide) is disclosed. The graft polymerization is accomplished by mixing the poly(ethylene oxide), the silane-containing monomer(s) and an initiator and applying heat. Preferably, the method is a reactive-extrusion process. The resulting modified poly(ethylene oxide) has improved water absorption characteristics and melt processabilities and may be used to make thermally processed articles, such as fibers, films and foams, that have improved properties over articles similarly processed from unmodified poly(ethylene oxide).