Phenol-aldehyde-amine resin/glycol curatives for energy absorbing polyurethanes

A process for producing a cellular polyurethane elastomer which comprises forming and curing a reaction mixture containing:

• (a) a polyol,
• (b) as a curative, the reaction product of:
• (I) a phenol which has at least one unsubstituted reactive position on the aromatic nucleus,
• (II) an aldehyde, and
• (III) an aromatic amine,
• (c) as a curative, an organic diol,
• (d) an organic polyisocyanate in an amount that provides from 0.8 to 1.3 isocyanato groups per active-hydrogen group in the reaction mixture,
• (e) a catalytic amount of catalyst for the curing of the reaction mixture to produce the elastomer, and
• (f) a blowing agent in an amount sufficient to produce a cellular structure in the elastomer,
• said reaction mixture containing from 99 to 30 parts by weight of (a) and from 1 to 70 parts by weight of (b) per 100 parts by weight of (a) and (b) and said reaction mixture containing from 1 to 35 parts by weight of (c) per 100 parts by weight of (a) and (c), with the proviso that the reaction mixture contains no more than 35 parts by weight of (b) and (c) per 100 parts by weight of (a), (b) and (c).