Evaluation of the Mechanical and Fire Resistance Properties of Rigid Tannin Polyurethane Foams with Copper Oxide Nanoparticles

In this study, a polymerized polyurethane foam was formulated from tannins extracted from Pinus radiata as polyol, and copper oxide nanoparticles (CuO-NPs) at a concentration of 2 % w/w as a nucleating agent. This produced a reinforced foam with better mechanical properties and fire resistance. The impact of the addition of CuO-NPs on the mechanical and thermal properties of the tannin foam was also studied. The properties studied were foaming process, foam density, cell morphology, flammability and thermal conductivity. The results revealed that the CuO-NPs incorporated in the foam formulation act as nucleation centers, which decrease the pore size, strengthen the cell walls, and improve mechanical properties. The tannin samples showed good thermal resistance performance with a limit oxygen index (LOI) higher than 21 %. The results obtained were contrasted with two foams, a commercial foam (SoudaFoam) and a foam generated with the same dissociate, but with a commercial polyol (LHT-112). The foam with NPs had an elastic modulus of 3.7 MPa and stress (max) of 1.13 MPa, which was higher than those of the foams used as controls.