Polyurethane foam lightweight concrete: Preparation, CO2 fixation properties and mechanism

Abstract

To enhance the carbon sequestration of concrete and the mechanical properties of polyurethane foam concrete (PFC), a novel formulation was developed using ordinary Portland cement, basalt stone powder, diphenylmethane diisocyanate, and polyether polyol. This study investigated the optimized production of PFC and its CO₂ capture efficiency. The optimal polyurethane crosslinking was achieved with a specific diphenylmethane diisocyanate (MDI) to polyether polyol (PP) ratio, resulting in PFC with ideal densities for structural applications. Comprehensive testing after a curing period of 48 hours yielded a maximum compressive strength of 9.16 MPa and an improved flexural strength of 4.3 MPa, demonstrating the formulation's effectiveness. Thermogravimetric analysis highlighted the CO₂ absorption capacities of PFC at various densities. Furthermore, an accelerated carbonization study revealed significant depth increases within the initial 8 hours. Microstructural analysis confirmed that lower-density PFC samples exhibited enhanced carbonization, with notable increases in CaCO₃ content, suggesting improved carbon sequestration potential. These findings indicate that the tailored PFC formulation not only strengthens material properties but also contributes to environmental sustainability by effectively capturing CO₂.