ABSTRACT
The use of Pulverised Fuel Ash (PFA) as a filler for low density polyurethane insulation foams has been evaluated. The chemical and physical interaction of PFA and polyurethane were investigated. The mixing characteristics of PFA/polyurethane was examined. PFA/polyurethane foams were tested to see if their properties were within the minimum properties specified in BS5608 (1986). Mixing was seen as the key factor in attaining a good quality foam with high loading levels of PFA. Methods of improving the mixing of PFA and polyurethane were examined. A longer mixing time was obtained by removing the catalyst from the polyurethane chemical system and adding it to the PFA/polyurethane mix at the end of the mixing period. This enabled a 30% PFA loading in polyurethane chemicals to be obtained with the properties of the resultant foam within those specified in BS5608 (1986). The study was extended to examine the effect which silane coupling agents have upon the properties of a polyurethane foam filled with 30% PFA. It was seen that silane coupling agents decreased the insulation properties of the foam. Fire tests were completed on PFA filled polyurethane foams. PFA improves the fire properties of a polyurethane foam by forming a char on the surface of the foam. Research and development work continues with PFA/polyurethane in a high density particle board.
