The structure–property relationships of water-dispersed polyurethanes based on tetramethyl xylene diisocyanate

Novel water-dispersed polyurethanes based on tetramethyl xylene diisocyanate (TMXDI), polycaprolactone or polytetramethylene glycols and alipbatic diamine chain extenders were synthesised. 2,2-bis(hydroxymethyl) propionic acid (DMPA) and triethylamine (TEA) were used respectively as potential carboxylic anionic emulsifying centres and neutralising agent in the resulting aqueous phase to form pendent quaternary ammonium salts. These were necessary to provide high hydrophilicity to the polyurethanes sufficient to make the polyurethanes easily dispersed in water without the assistance of organic solvent. [Continues.]