UV‐shielding by a polyurethane/f‐Oil fly ash‐CeO₂ protective coating

Abstract

A waste material called oil fly ash (OFA) was acid-functionalized, yielding f-OFA-COOH, which was then reacted with cerium oxide (CeO 2) to make CeO 2functionalized OFA, or f-OFA-CeO 2. Pristine OFA and f-OFA-CeO 2 were used to make waterborne polyurethane (WBPU) dispersions, referred to as WBPU/ OFA and WBPU/f-OFA-CeO 2 , respectively, with defined OFA and f-OFA-CeO 2 content. All the dispersions were applied to mild steel as organic coatings to evaluate their protective properties, such as their hydrophobicity, adhesive strength and UV-shielding resistance. These protective properties varied based on the OFA and f-OFA-CeO 2 content. The highest water contact angle, minimum water swelling and maximum adhesive strength were found using WBPU/ f-OFA-CeO 2-20 coating (using 2.00 wt% f-OFA-CeO 2), which also showed the maximum ultraviolet (UV) absorption via UV-vis spectroscopy analysis. This UV shielding result also matched field test results, as that coating was found to exhibit the lowest UV degradation near a marine atmosphere, as shown by Xray photoelectron spectroscopy (XPS) analysis. The least affected hydrophobicity was also recorded for the sample with the WBPU/f-OFA-CeO 2-20 coating.

UV-Protected Polyurethane/f-Oil Fly Ash-CeO2 Coating: Effect of Pre-Mixing f-Oil Fly Ash-CeO2 with Monomers

“…However, PU coatings considered for outdoor applications still encounter challenges regarding UV rays [2,7,8]. Coatings often degrade under UV rays.…”

“…Recent research proved that UV degradation can be delayed when proper nanoparticles and organic compounds are used [8][9][10]. However, the use of nanoparticles is challenging, as PU coatings have the tendency to sacrifice their mechanical strength and adhesive strength in the presence of improper or excessive amounts of nanoparticles [7,8]. Moreover, long-term stable PU/nanocomposite dispersion is not easily achievable [11,12].…”

“…OFA is a byproduct generated by power and desalination plants in Saudi Arabia [8]. OFA is mainly a carbon (90%)-based spherical particle [8,13].…”

“…OFA is a byproduct generated by power and desalination plants in Saudi Arabia [8]. OFA is mainly a carbon (90%)-based spherical particle [8,13]. The local OFA has very limited uses; it is mainly used in the construction sector in very limited quantities.…”

“…OFA thus presents a considerable burden not only for the government but also for the environment, representing a major threat to ecosystems. Recently, a few researchers [8,13,14] in Saudi Arabia have demonstrated some other promising applications of OFA in organic coatings. OFA and functionalized OFA (f -OFA) can improve the thermal, mechanical and protective properties of polymers [8,13].…”