| abstract |
Polyurethanes are made by reacting, in one or more reaction steps, a) at least one organic polyisocyanate, b-1) one or more polyols having a hydroxyl equivalent weight of greater than 250 g/mol and a nominal hydroxyl functionality of 2 to 4 and b-2) at least one alkoxylated Mannich base to produce a polyurethane polymer having a density of at least 750 kg/m3 and a hard segment content of 20 to 80% by weight. |