Multi-oxide doping of PMMA: crystallographic and morphological insights from XRD and SEM

Polymer-based composites have emerged as promising materials for radiation shielding; however, most previous studies have focused on mono- or binary-oxide systems, overlooking the synergistic interactions among multiple oxides with varying atomic numbers. This work develops advanced polymethyl methacrylate (PMMA)-based composites reinforced with a complex combination of metal oxides to enhance gamma-ray attenuation. The composites were formulated with the composition [PMMA: X% Bi2O3, (30 − X) % MoO3, 40% B2O3, 20% SiO2, 9% Na2O, and 1% Fe2O3], where X = 5%, 10%, 15%, and 20%. Mechanical mixing was employed to achieve uniform dispersion of the oxide fillers within the PMMA matrix. Structural and morphological analyses were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), while radiation shielding performance was evaluated in terms of transmittance (T), absorbance (A), and the linear attenuation coefficient (μ). The XRD results revealed an amorphous PMMA matrix with partial crystallinity induced by oxide incorporation. SEM micrographs confirmed homogeneous particle dispersion and improved surface morphology, especially for the composite containing 20% Bi2O4 (S4). This sample exhibited the lowest transmittance and highest linear attenuation coefficient, demonstrating superior shielding efficiency. These findings underscore the crucial influence of oxide composition and microstructural uniformity on the radiation attenuation capability of polymer–oxide composites.