Polyurethane foams based on amino polyols

摘要

An improved method for preparing amino polyols is disclosed. The method is the Mannich condensation of phenol, formaldehyde and diethanolamine in a molar ratio of (1:1:1), and then alkoxylation with a mixture of ethylene oxide and propylene oxide in a weight ratio of about 5:95 to 20:80 to form an amino polyol of hydroxyl number 440 to 515. The method gives higher yields of aromatic amino polyols of lower viscosity than those of the comparative example.