Influence of Niobium Pentoxide and Sintering Temperature on Mechanical and Electrical Properties of Glass-ceramics Obtained from Recycled Automotive Windshields

Abstract

Automotive windshield represents a large volume of solid waste due to limited recycling. Glass-ceramics were produced from discarded windshields with Nb₂O₅ as a nucleating agent at concentrations of 0, 5, 10, and 15 wt% at 700 and 800 °C sintering temperatures. Mechanical and electrical characterizations of glass-ceramics were performed. Equibiaxial flexural strength was performed and related to porosity. At 700 °C, Nb₂O₅ favors the monoclinic NaNbO₃ phase with perovskite structure. At 800 °C, high Nb₂O₅ content formed crystalline phases of perovskite and quartz. Dielectric constant and electrical conductivity increased with the addition of Nb₂O₅, reaching 64 and 4.3 μS/m for 15 wt% Nb₂O₅ at 700^oC. At 800^oC, niobium pentoxide reduces the biaxial flexural strength from 28.7 to 14.4 MPa; while increasing the electrical conductivity from 0.10 to 0.33 µS/m for samples with 0 and 15 wt%.

Keywords:
Recycled windshield; niobium pentoxide; flexural strength; electrical properties