Enhancement in Physiomechanical, Thermal and Morphological Characteristics of Zirconia and Reduced Graphene Oxide Modified Hybrid Polymer Nanocomposites for Orthopedic Application

Polymeric composite materials are widely used to develop artificial implants and prosthesis components. These materials are closer to the original tissue in mechanical and biological qualities required in total joint replacements. In this series, the ultra-high molecular weight polyethylene (UHMWPE) is primarily utilized in arthroplasty applications due to its biocompatibility, chemically stabilized, and excellent mechanical qualities. However, it still falls short of achieving the required orthopedic specifications. The present work explores the development and characterization of UHMWPE-based nanocomposites in view of enhanced orthopedic performances. For this, the different concentrations of rGO (0.5, 1.0, and 1.5 wt%) and nano-sized zirconia (5 and 10 wt%) were added to the UHMWPE matrix. A combination of total seven sets of nanocomposite samples was fabricated, including the pristine UHMWPE. A modified Liquid-Phase Ultrasonication (LPU) process was used to disperse the reinforcing nanofillers, and the Hydraulic Hot Pressing (HHP) method prepared the final standard samples. The developed specimens were subjected to Tensile, flexural, Shore-D, and thermal investigations for physiomechanical and thermal characteristics. Afterward, X-ray diffraction analysis (XRD), Dispersive X-ray Analysis (EDAX), Fourier-transform infrared spectroscopy (FTIR), and morphological investigation were explored to examine the chemical and structural features of prepared nanocomposites. The addition of ceramic filler (ZrO2) enhances wear capability as verified by the plasticity index, along with improved strength and hardness of the polymer matrix. This results in rGO-aided lamellar layers arrangements and microfibers between the crystals. When compared to an unfilled polymer, the bio nanocomposite containing 1 wt% rGO and 5 wt% ZrO2 in the UHMWPE matrix showed a 7.2% improvement in microhardness. The bio nanocomposite samples have a crystallization degree of 52.37% at the same bi-filler concentration. Adding 1% rGO wt% and 5% ZrO2 wt% to the UHMWPE made it exclusively well-suited for various biomedical applications. The findings indicate that the combined effects of rGO and ZrO2 nanoparticles can be utilized to create a long-lasting articulation liner for joint assemblies, including hip, shoulder, and knee part assembly. [GRAPHICS] .