Hydration-induced reinforcement of polyurethane-cement foams: Solvent resistance and mechanical properties

Solvent resistance and mechanical properties of hydration-induced reinforcement of polyurethane-cement foams are discussed. The results of solvent swelling measurements are reported to highlight the significant influence of the interconnected inorganic acicular structure type reinforcement within the walls of the cells of newly developed polyurethane or cement hybrid foam. It is demonstrated that the cement particles are discretely dispersed in the polyurethane matrix before the hydration step, while a state of interconnected network is acquired after the hydration step. This process provides a high resistance to solvent swelling after hydration, along with a large increase in modulus and strength. The polyurethane/cement foams have been prepared by mixing the polyol with catalysts, surfactants, water, and anhydrous cement particles and methylene-diphenyl di-isocyanate.