Waterborne polyurethane (WPU) coatings used for moisture protection of surfaces have been used broadly. They have been considered environmentally friendly because their synthesis releases less or no volatile organic compounds (VOCs) to the atmosphere. With the Covid-19 pandemic concerns, cleaning protocols of these surfaces have been applied and scientific knowledge about the effects of these liquids on WPU surfaces is necessary. In this work, diffusion experiments were performed using four liquids, in pure WPU and WPU filled with graphene oxide (GO). Detergent had the most severe effect on polyurethane films, causing severe cracks and weight loss. Diffusion parameters of HCl 5% and HCl 10% were greater in WPU/GO nanocomposites than in pure WPU. Mechanical tests under chemical aging showed that alcohol reduced most the tensile strength and Young modulus. Overall, GO protected the films for all liquid exposures, increasing their tensile strength and Young modulus.
Poly(methyl methacrylate) (PMMA) is a polymer that can be used in applications requiring its exposition to gamma radiation, nevertheless, the radiation induces main chain scission backbone, leading to modification in some properties. Therefore, using materials such as layered double hydroxide (LDH), was evaluated as a new radiation shielding agent. This work synthesized LDH and added to PMMA by an in-situ polymerization method. Viscosimetric analysis showed that LDH at 0.25 wt% concentration promotes polymer radiolytic protection of 90% against damage caused by gamma radiation. The topographic images obtained by AFM revealed increasing PMMA/LDH film roughness, which impacted the lower film transmittance. The combined effect of LDH and gamma radiation interferes with the degradation process of PMMA, promoting reduced rigidity, greater mobility of polymer chains, and lower optical gap energy. Thus, these results open a promising path for using LDH as additives in polymers exposed to gamma radiation.