A series of waterborne polyurethane (WPU) dispersions were synthesized from isophorone diisocyanate (IPDI)

polyester glycol (T-1136) and dimethylolpropionic acid (DMPA) via prepolymer mixture. It was found that the solid content

hydrolytic stability of PU emulsion and the cold crack properties of the cast film of WPU could be improved by using polyester and polyether as soft segment. The mechanical properties of the cast film increased and the elongation at break decreased with increasing content of hard segment and NCO/OH ratio. The water-resistance

solvent-resistance and wetting rub properties of the cast film of WPU would be improved by increasing the amount of TMP. Testing of the cast film showed natural gloss with silky hand feel

excellent adhesion and cold crack properties

water resistance

solvent resistance

and rub-resistance at 40% hard segment content

1.3—1.5 of NCO/OH ratio and 3%—5% of TMP content.