Synthesis of a novel UV crosslinking waterborne siloxane-polyurethane

A novel UV crosslinking waterborne siloxane-polyurethane (UV-WPU) was synthesized using isophorone diisocyanate (IPDI), glycidyl azide polymer (GAP), polytetramethylene glycol (PTMG), dihydroxybutyl terminated polydimethylsiloxane (DHPDMS), dimethylol propionic acid (DMPA) as main materials. The structure of UV-WPU was verified using Fourier transform infrared spectroscopy (FTIR). Attenuated total reflectance (ATR) was used to study the UV crosslinking reaction kinetics of UV-WPU under UV irradiation. The properties of UV-WPU coatings by UV and thermal curing was comparatively analyzed by thermal gravimetric analysis (TGA), as well as gel fraction, water resistance and water contact measurements. The gel fraction and TGA analyses also confirmed the formation of crosslinking structure in the UV-WPU structure after UV curing process. UV-WPU cured by UV showed good thermal stability, surface properties and water resistance.