Waterborne polyurethane/3-amino-polyhedral oligomeric silsesquioxane (NH2-POSS) nanocomposites with enhanced properties

To study the influences of 3-amino-polyhedral oligomeric silsesquioxane (NH 2 -POSS) on the properties of waterborne polyurethanes (WPU), a series of NH 2 -POSS modified WPUs were synthesized by using polypropylene glycol (PPG-2000, PPG-310), 2,2-dimethylolpropionic acid (DMPA), isophorone diisocyanate (IPDI), and NH 2 -POSS via a one-pot reaction and a high shear emulsification method. The results showed that when the NH 2 -POSS amount in the WPU/NH 2 -POSS nanoemulsion was 5.73 wt% (WPU2, based on the weight of WPU resin), its viscosity was 2.496 MPa · s and its Zeta potential was 63.7 mV(pH = 6.1), showing lower viscosity and better dispersion stability. The particle size of WPU2 is smaller than that of WPU0, and the polydispersion index (PDI) of WPU2 was decreased from 5.520 to 3.837 indicating a higher crosslinking density. In addition, the thermal stability of WPU/NH 2 -POSS nanoemulsion was increased with the content of NH2-POSS from 0.00 to 13.19%. The water contact angle values for the WPU2 (84.5°) were higher than that of WPU0 (80.2°), showing an improvement of the hydrophobic properties. This WPU/NH2-POSS nanocomposites can be used for making coating adhesive for textile and hosting matrix for making multifunctional nanocomposites.  Graphical abstract