Investigating the Mechanical and Tribological Properties of Biowaste Derived Bioactive Borosilicate Glass Incorporating Strontium Oxide

Abstract The primary goal of the current research paper is to investigate the mechanical and tribological behavior of biologically active glass materials consisting of 31B2O3–(20 − x) SiO2–24.5Na2O–24.5CaO and xSrO (in mol. %). The specimens were fabricated partly using biowaste material, in which silica and calcium oxide were derived from rice husks and egg shells, respectively. The produced specimens underwent immersion in simulated bodily fluid for a week to observe their bioactive response. The findings from Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses validated the existence of a hydroxyapatite (HA) layer on the specimen surfaces. Further, XRD data showed an increase in peak intensity after SrO was incorporated, suggesting that it played a supporting role in boosting bioactivity. The mechanical investigations indicated that the addition of SrO adversely affects both hardness and compression strength. The highest levels of hardness and compression strength were observed in borosilicate glass (BSG)-0, namely, 6.49 GPa and 73.81 MPa, respectively. Following the inclusion of SrO, these values decreased to 4.72 GPa and 35.03 MPa for BSG-5, respectively. The abrasion wear test demonstrated that BSG-5 had the highest wear rate, while BSG-0 exhibited the lowest wear rate among all specimens at a 30 mm track radius, consistent with the outcomes of mechanical tests. The heightened concentration of strontium correlated with amplified abrasion and erosion, leading to more significant damage in surrounding regions. Despite the tradeoff between enhanced bioactivity and diminished mechanical strength and wear resistance, incorporating strontium oxide makes the glass suitable for applications prioritizing bioactivity, such as bone filling and dental contexts.