The carboxyl group containing aqueous-based polyurethane (PU) dispersions were prepared from isophorone diisocyanate, poly(propylene glycol)-1000, and 2,2-dimethylol propanic acid via a PU prepolymer process. The amino content of this amino-terminated aqueous-based PU system was determined by a styrene oxide titration method. Glycidyl methacrylate (GMA) copolymer emulsions were prepared by an emulsion polymerization of GMA and other alkyl acrylates. The curing behavior of the GMA copolymer was demonstrated by a model reaction of the GMA copolymer with ethylenediamine. In the same token, the reaction took place between the PU amino groups and the GMA copolymer epoxides at ambient temperature and resulted in the formation of a hybridized homogeneous copolymer. This hybridized copolymer also consisted of carboxylic acid on the PU fraction after drying. Carboxylic acids of the copolymer were exchanged with calcium ion and this ionic coordination resulted in a calcium ion-crosslinked copolymer. The physical and mechanical properties and the thermal behaviors of the hybridized copolymers were evaluated.
Journal of Applied Polymer Science 71(6), pp.903-913