Impact of waste fillings on the thermoset rigid polyurethane foam

Fly ash (FA) and cement kiln dust (CKD) are waste materials with a lot of promise in polyurethane (PUR) technology as modifiers of mechanical and thermal characteristics. The objective of this study was to investigate the effects of the addition of cement kiln dust and fly ash as fillings materials to the rigid polyurethane foam. Density, compressive strength, and thermal conductivity were studied. Foam density increases with increasing the two filling materials due to decreased cell size and foam volume. The compressive strength of the foams increased after adding low amounts of the two filling materials. A decrease in compressive strength was recorded at higher amounts of the filling materials due to the deterioration of the cell morphology. The thermal conductivity was decreased with increasing the percentages of the two filling materials.