Ambient curable waterborne polyurethane coating based on the reaction between carboxyl and aziridinyl groups

The water resistance and mechanical properties of polyurethane coatings were improved by the reaction between carboxyl and aziridinyl groups for ambient curing of waterborne polyurethane coatings.The waterborne carboxylic polyurethanes and aziridinylic polyurethane cross-linking agent were synthesized from toluene diisocyanate,polyethylene glycol,2,2-dimethylolpropionic acid,glycolic acid and 1-aziridinyl ethanol.Their structures were characterized by 1H NMR.The thermal properties,water resistance,and mechanical properties of the coatings were then investigated.The results indicate that the two components are compatible and the cured coatings possessed excellent water resistance and mechanical properties.