Mechanical properties and decomposition performance of peelable coating containing UiO-66 catalyst and waterborne silane-terminated polyurethane dispersions

Abstract

An easily peelable coating was prepared using silane-terminated polyurethane dispersions (SPUDs) and UiO-66 catalyst (a zirconium(IV)-based metal-organic framework), to capture and decompose the nerve agent simulant, methyl paraoxon (MPO), at room temperature. SPUDs were used as the binder. The peel strength of the SPUD film containing UiO-66 decreased with increasing UiO-66 content, and the film with 40 wt% UiO-66 could not be easily peeled off. In contrast, the SPUD/PVB/UiO-66 peelable coating film could be easily peeled off. With increasing UiO-66 content, the Young's moduli of the SPUD/UiO-66 and SPUD/PVB/UiO-66 coating films gradually increased, while the elongation decreased. The increase in the glass transition temperature was less than approximately 5%, depending on the UiO-66 content of the SPUD/UiO-66 film. Two peaks of tan delta appeared for the SPUD/PVB/UiO-66 coating film. As the UiO-66 content increased, the second peak shifted to the right. This could be attributed to the bond strength between the mixed polymeric binder and the nanoparticles. Furthermore, MPO decomposition by the SPUD/PVB/UiO-66 coating film increased with increasing UiO-66 content. These findings suggest the possibility of the development of a peelable coating film for the capture and decomposition of MPO.