Abstract: Polyurethane elastomers, low density high resiliency polyurethane foams and compositions and processes for preparing urethane foams and elastomers comprising reacting a mixture of a polyalkylene polyol having reactive hydrogen atoms as determined by the Zerewitinoff method exhibiting a molecular weight of at least 500, at least one organic polyisocyanate, and as a cross-linking agent at least one sulfur-containing polyamine compound exhibitng the formula: ##STR1## wherein R is a hydrocarbon, and R' is selected from the group consisting of hydrogen, halogens, and hydrocarbons.