Synthesis and characterization of new continuous phosphate glass fibers intended for structural engineering applications: Structure/property relationships

Abstract

Nowadays, phosphate glass fibers (PGF) are considered quite competitive respective to conventional glass fibers. This work focus on the development of PGF fibers intended for structural engineering applications such as composite reinforcement for building and automotive fields. For this purpose, two series of phosphate glasses based on 52P₂O₅–24CaO-13MgO-(11-(X+ Y + Z)) K2O-XAL₂O₃-YF₂O₃-ZTiO₂; (X=1; 3; 5, Y=0; 5, Z=0; 1 mol%) were processed and transformed into phosphate glass fibers by melt spinning. The resulting fibers were characterized. XRD analysis confirmed the non-crystalline nature of phosphate glasses. In addition, the substitution of K₂O by Al₂O₃ and by the combination of Al₂O₃, Fe₂O₃ and TiO₂ in the composition of phosphate glass could lead to a significant increase in fiber density from 2,16 g/cm³ to 2,80 g/cm³. The stability of the produced phosphate glass fibers was examined using two methods: weight loss at 37 °C and dissolution kinetics under different pH levels (4, 7, and 12). The results showed that the chemical resistance of the PGF fibers was improved with up to 99 % increase respective to the original formulation. In addition, the mechanical properties of the spinnable phosphate glass manufactured by replacing K₂O oxide by Al₂O₃ oxide were improved, such a substitution led to a maximum tensile strength and modulus of 2668 MPa and 140 GPa, respectively. Therefore, the tensile proprieties were improved by 75 % compared to the original formulation. This comparative study between phosphate glass fibers (PGF) and traditional fibers highlight similar tensile strength but combined to notable enhancements in chemical stability through cation addition, expanding their potential use in composite and biomedical materials. Finally, a correlation analysis of mechanical performances was carried out. It was observed that the results obtained using the statistical methods were consistent with the experimental data.