Mechanical Properties and Thermal Degradation Behaviour of Polyurethane Composites Incorporating Waste-Glass Particles

This study investigated the effect of hot-pressing conditions, including the curing temperature, curing time and the applied pressure, on the flexural properties of polyurethane (PU) composites incorporating 88 wt.% (Glass/PU-88/12) and 95 wt.% (Glass/PU-95/5) recycled glass particles. Hot-pressing (cure) temperatures between 100 °C and 180 °C were investigated with the objective to shorten the cure cycle, thereby increasing the production rate of the glass/PU composites to match industrial scales. The hot-pressing time varied between 1 min and 30 min, while the pressure varied between 1.1 MPa and 6.6 MPa. Further to investigating the hot-pressing conditions, the effect of post-curing on the flexural properties of glass/PU composites was also investigated. Microstructural analysis was used to identify the interactions between the glass particles and the PU matrix, explore the void content and establish the relationship between the microstructure and the mechanical properties of the resultant glass/PU composites. Glass/PU composites incorporating 5 wt.% (Glass/PU-95/5), 10 wt.% (Glass/PU-90/10) and 12 wt.% (Glass/PU-88/12) were manufactured under optimised hot-pressing conditions (temperature = 100 °C; cure time = 1 min; pressure = 6.6 MPa) and evaluated under flexural, tensile and compression loadings. Furthermore, the high-temperature stability of the composites was evaluated using thermogravimetric analysis. This study demonstrates the feasibility of upcycling glass waste into value-added materials for potential use in the construction and building industry.