This oligomer is prepared by the reaction of isophorone diisocyanate (D) with polyol polypropylene glycol (P) and a subsequent endcapping of non-reacted terminal isocyanato groups with 2-hydroxyethyl acrylate (A) (Figure 2).
The two reactions mentioned above lead not only to the unique product ADPDA, with a chemical structure presented in Figure 1, but also to other products like ADPDPDA, ADPDPDPDA, etc., and low-molecular-weight (MW) product ADA.2 Urethane oligomer synthesis is performed in such a way that NCO equivalents are equal to equivalents of all the reactive OH groups. That way, independent of product distribution, there are no loose NCO or OH groups after completion of the reaction.