Impact of SiO2 and TiO2 Nanoparticles on the Elasticity and Aging Resistance of Polyvinyl Acetate (PVAc) Adhesive

Adhesive modification with nanoparticles affects multiple adhesives properties, making it essential to evaluate and compare changes across all key characteristics—existing positive and limiting properties. This study investigates the impact of silica (SiO2) and titanium dioxide (TiO2) nanoparticles on the elasticity and aging resistance of PVAc adhesive. Tensile properties were determined according to ISO 527-3:2018, with Young’s moduli of elasticity Ε, and stress–strain curves for neat PVAc, nano-SiO2 PVAc, and nano-TiO2 PVAc adhesive. Material toughness (UT), failure stresses σf, and failure strains εf were also calculated. After UV exposure (0, 48, and 96 h), according to ISO 9142:2003, samples were characterized by Fourier-transform infrared spectroscopy (FTIR). Analysis of variance (ANOVA) was performed to determine if there is a statistically significant difference in material toughness between neat PVAc and nano-modified PVAc adhesives, as well as changes in FTIR spectra of paper–adhesive samples before and after UV exposure. The Bonferroni post hoc test was used to identify specific group differences. The results showed that SiO2 nanoparticles improved PVAc elasticity by 9.15%, while TiO2 nanoparticles reduced elasticity by 44.47%. FTIR analysis revealed similar behavior in both nano-modified and neat PVAc adhesives after UV exposure, indicating that aging resistance was preserved with the addition of SiO2 or TiO2.