Abstract
Methanolysis of polyurea (PUA) in the subcritical carbon dioxide was investigated. PUA was synthesized from 4,4'-diphenylmethane diisocyanate and water in the N,N-dimethylformamide. The methanolysis were performed in the temperature range from 160 to 190 °C and under supercritical state of carbon dioxide at pressures from 3.5 to 13.8 MPa. The methanolysis of PUA at 190 °C in the pressure range from 4.3 to 7.3 MPa gave methanol soluble products composed of dimethyl-carbamate, diamine and carbamate-amine compounds in 97-99 % conversion.
