WATER FEED METHODS TO CONTROL MW DISTRIBUTION AND BYPRODUCTS OF THE CARBAMYLATION OF UREA

摘要

The present invention provides methods for making a polycarbamate by feeding a) a urea in fluid form into a reaction medium containing b) an alkyd polyol, such as a short or med oil alkyd polyol to form a reaction mixture and then carbamylating the alkyd polyol by heating the reaction mixture while feeding water in to the reaction mixture, preferably, in the presence of one or more c) carbamylation catalysts. The polycarbamate of the present invention when combined with a polyaldehyde or an acetal or hemiacetal thereof as a second component makes a multicomponent composition that is substantially isocyanate-free, and cures at a temperature of from 0 °C to less than 80 °C to form a crosslinked polyurethane.