TRANSPARENT POLYURETHANE-HYDROGEL COMPOSITION, METHOD OF MAKING TRANSPARENT POLYURETHANE-HYDROGEL COMPOSITION, AND AIR-FRESHENER APPLICATION

摘要

A transparent polyurethane-hydrogel composition includes a reaction product in aqueous solvent of a prepolymer and a water-soluble crosslinker in the substantial absence of organic solvent, and such a composition can be prepared by admixing a prepolymer and a water-soluble crosslinker in aqueous solvent and in the substantial absence of organic solvent. A prepolymer is present in an amount of no greater than about 5 weight percent based on total weight of all hydrogel components. The prepolymer is generally prepared from at least one water-soluble polyol and an isocyanate. A water-soluble crosslinker generally has a crosslinker functionality of at least 2 and is selected to provide a site ratio of initial isocyanate to crosslinker (i.e., moles NCOxfunctionality/moles crosslinkerxfunctionality) of at least about 1.5 and no greater than about 2.6. In one embodiment, a crosslinker is effective to react with and solubilize residual isocyanate concurrently with the reaction between prepolymer and crosslinker. A transparent polyurethane-hydrogel composition has desirable gel physical properties and is useful for an air-freshener application.