Transparent UV-Cured Polyurethane–Surfactant Coatings with Antifogging Properties

Abstract

Fogging on optical devices may severely impair vision, resulting in unacceptable adverse consequences. Transparent antifogging coatings play an important role in daily life, because they can effectively enhance transmission of light and meanwhile prevent water condensation considerably. Herein, highly transparent antifogging polyurethane coatings are designed and fabricated via a UV-assisted cross-linking method. Initially, isophorone diisocyanate, poly(ethylene glycol) (PEG), and 2,2′-bis(hydroxymethyl)butyric acid (DMBA) were thermally polymerized to obtain a series of amphiphilic polyurethane prepolymers. Afterward, polyurethane prepolymers were end-capped by various surfactants (OP-x) and pentaerythritol triacrylate (PETA). Upon photoirradiation, the UV-cured polyurethane coatings with the cross-linking structure were obtained. Subsequently, the polyurethane coating has a hierarchical surface due to microphase separation. The wettability of coatings could be mainly attributed to the cooperative effect between the hierarchical surfaces and the hygroscopicity of the surfactant molecules. The polyurethane coating enables water to rapidly spread out, fulfilling the enhanced antifogging function (without forming water droplets). This antifogging material may find potential application in microdevices and engineering systems that operate in a cold or humid environment.