New pathways were explored to make aqueous polyurethane dispersions without the co-solvent n- methylpyrolidone (NMP). This includes methods to process these materials with alternate co-solvents as well as with co-solvents that can be removed from the product during processing. Chemical modifications of the polyurethane were investigated in order to use these alternative processes. ew co-solvent free polyurethane dispersions, useful as coatings for wood floors, have been developed using an alternative process. These materials have outstanding properties, are low odor, and free of NMP.
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