Hydrophobic, Water-Dispersible Polyurethane: Roleof Polybutadiene Diol Structure.

Preparationof stable, free-standing elastic film with hydrophobicsurface from water-dispersible polyurethanes (WDPUs) is a challengingtask. Here, we have prepared WDPUs from polybutadiene-based diolsand the resulting PU films are satisfying the requisites. Two typesof diols, namely, hydroxyl-terminated polybutadiene (HTPB) and terminal-functionalizedHTPB with dinitrobenzene (DNB) [HTPB-DNB], were used to make WDPUsand the effects of diol structures were investigated. The synthesizedWDPUs displayed particle morphology with size in the range of ∼130–270nm and more than 1 year storage stability. WDPUs yielded stable andfree-standing films upon curing and the resulting films showed highthermal and mechanical stabilities. The contact angle of the filmsis in the range of ∼80–100°, attributing the hydrophobicnature of the surface. Hard segment content of the PU varied from30 to 40% (by weight) to tune the properties of WDPUs and the resultingfilms. [ABSTRACT FROM AUTHOR]