thylene glycols, polypropylene glycols, polyoxyalkylene polyethers, polyester polyols, polyol adducts derived from ethylene and/or propylene oxide and methylenedianiline and polyethylene polypheny lamine mixtures, vinyl reinforced polyether polyols, e.g. polyols obtained by the polymerization of styrene or acrylonitrile in the presence of the polyether, polyacetals from glycols such as diethylene