Synthesis, structural, and characterization of polymethylmethacrylate matrix−ZnO nanocomposite

The current work investigates the effect of incorporating zinc oxide nanoparticles (ZnO NPs) into the polymer matrix polymethylmethacrylate (PMMA), focusing on structural, thermal, mechanical, and antimicrobial properties. The synthesized polymer nanocomposites, prepared via free radical emulsion polymerization, were characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and density measurements. Furthermore, the antibacterial and antimicrobial properties of the polymer nanocomposites were assessed against gram-negative bacteria (E. coli), gram-positive bacteria (S. mutans), and the fungus (C. albicans). Moreover, the mechanical characteristics, including Vickers micro-hardness, Young's modulus, tensile strength, and elongation at break, for pure PMMA and PMMA/ZnO nanocomposite films have also been examined. The results confirm that the structure of the host matrix changes slightly upon the addition of ZnO NPs. The density measurement shows an increase, and the thermal stability is enhanced by ~ 6% for an optimum concentration of ZnO NPs addition. Additionally, the hardness number reaches its maximum value with an increase of ~ 13.5%, which is a statistically significant difference. Moreover, mechanical properties (e.g., Young's modulus, tensile strength) and antibacterial and antimicrobial properties have shown remarkable changes. In conclusion, this work emphasizes optimal 3 wt% loading, attributed to the good dispersion of ZnO NPs, highlighting enhanced performance that can be used in denture-base applications.