Polyurethane isocyanate reacts with urethane and urea groups

carbamate and urea groups still contain activity hydrogen can continue to react with isocyanate groups to form cross-linking bonds. the activity of urethane group and urea group is lower than that of alcohol, water, amine, phenol, etc., as shown in table 2-4. most tertiary amines do not show strong catalytic effects on these two reactions,…