Monodispersed calcium oxalate as highly effective support filler in PMMA-based nanocomposite

This study focuses on the synthesis of monodispersed CaC2O4 particles of cubic and donut-shaped novel morphologies and the ultrasonic-assisted in-situ polymerization of PMMA/CaC2O4 in the presence of native CaC2O4 and commercial CaC2O4 particles (0.2-0.8 wt%). The current study explored that particle loading played its role in defining the optimal conditions, whereas the particle morphology, uniformity, concentration, and reaction parameters of the fillers greatly influenced the properties of the resin-based nanocomposites. These observations confirmed that the calcium oxalate filler nanoparticles had an obvious effect on the tribological and mechanical properties of the as-fabricated composite. The optimum concentrations of fillers for enhanced properties of the composite were 0.4, 0.6, and 0.8 wt%, respectively for donut-shaped, cubic-shaped, and commercial calcium oxalate. The incorporation of donut-shaped particles showed enhanced properties as compared to nanocomposites consisting of commercial and cubic-shaped CaC2O4 particles. Enhancements in the properties of nanocomposites for different loadings of donut-shaped CaC2O4 as compared to blank PMMA are anti-wear = 51.02 & PLUSMN; 0.15%, COF = 66.60 & PLUSMN; 0.4%, and microhardness = 10.50x & PLUSMN; 0.06. These improved properties compared to the previous literature are essentially attributed to the particle morphology, size, uniformity, and uniform dispersion of CaC2O4 in the polymer matrix due to intense micro-convection generated by sonication.