Water vapor permeability and self‐cleaning properties of solvent‐free polyurethane improved by hollow nano‐TiO₂ spheres

Abstract

In the synthetic leather industry, solvent-free polyurethane film (SFPU) was poor in water vapor permeability (WVP) and washability. In this study, we introduced the hollow nano-TiO 2 spheres (HNTSs) with high photocatalytic performance and permeability performance as well as large surface area into the SFPU film to endued its superior water vapor permeability property, selfcleaning performance and water resistance. First of all, HNTSs were prepared via the controllable chemical route using HF for internal corrosion of solid nano-TiO 2 spheres, and then introduced into hydroxyl prepolymer to prepare solvent-free polyurethane/HNTSs composite film. The results of SEM, FT-IR and UV analyses indicated HNTSs were successfully dispersed evenly into SFPU. Application experiment results showed that the addition of HNTSs with hollow structure had an important effect on the WVP, photocatalytic performance, mechanical property, the water vapor transmission rate, self-cleaning performance as well as tensile strength were increased by 111.98%, more than 100%, and 36.368%, respectively.

Self-Cleaning Surfaces of Polyurethanes

“…Recent studies showed an introduction of hollow nano-TiO 2 spheres (HNTSs) with high photocatalytic and permeability performances as well as introducing large surface area into the PU film to endue its superior water vapor permeability property, water resistance along with desirable self-cleaning performance [26].…”

Recent progresses in super-hydrophobicity and micro-texturing for engineering applications

“…Additionally, when the adhesive force between the droplet and dust particles exceeds the adhesion between dust particles and surface. These conditions result in easy rolling of the droplet taking along the micro-sized dust particles and/or contaminants present on the surface making it a selfcleaning surface [37,38].…”

Effect of nano TiO2 on the cellular structure and mechanical properties of wood flour/polypropylene composite foams via mold‐opening foam injection molding

“…[25][26][27][28][29][30] The mainly is due to nanoparticles can significantly enhance the viscoelasticity and crystallization of the matrix, thereby improving the cell structure and mechanical properties of the foam. [31][32][33][34][35] Nano TiO 2 not only exhibits advantages of small particle size, large specific surface area and high surface activity, but also has strong stability, photocatalytic activity and UV shielding ability, [36][37][38] due to amphoteric oxide, a differentiated traditional nanoparticle filler generate a great expectation for foamed WPC. However, to the author's knowledge, there have been very few studies of the injection molding of WPC using nano TiO 2 particles to improve the foaming behavior and mechanical performances of PP-based WPC.…”