Effects of soft segments on the waterproof of anionic waterborne polyurethane

To study the waterproof of coating materials, a series of waterborne polyurethanes were prepared with different kinds and molecular weight of polyols. IR spectroscopy was used to check the end of polymerization reaction and characterization of polymer. The study was carried out by increasing the waterproof of various coating agents through variations of soft segments. We introduced laser-scattering equipment, Brookfield digital viscometer, JC2000C instrument, scanning electron microscope (SEM), and atomic force microscope (AFM) to investigate the particle size, viscosity, contact angle, and morphology of the coated fabric. In short, results displayed waterproof as follows: 3146 similar to 8200 mm H2O (IPDI=30 %) in various polyols and 5421 similar to 8748 mm H2O (R=1.6) of different molecular weight of poly(butylene adipate) (PBA). The higher water resistance belonged to PTMG-WBPU and WBPU-1000, respectively. Experimental results indicated that water resistance may be controlled by not only the types of soft segments, but also the molecular weight.