Synthetic cork-like material and method of making same

Synthetic cork-like stoppers for liquid containers comprising a fine closed cell foam produced by extrusion in rod form of a foamable mixture of polyolefin and a foaming agent together with an ethylene/methacrylic acid copolymer based ionomer resin, the resulting ionomer modified foam rod having a matte outer surface and a substantially uniform density throughout its cross section of from 12 lbs/cu.ft. to 17 lbs/cu.ft. and a non-leveling coating of moisture impervious material impregnating said matte surface, said material having a substantially higher coefficient of friction than the surface of the foam per se.