Recycling and Application Characteristics of Fly Ash from Municipal Solid Waste Incinerator Blended with Polyurethane Foam

In this study, different fractions of fly ashes, poly (tetramethylene glycol) (PTMG), and excess 4, 4′-diphenylmethane diisocyanate (MDI) were added into a reactor to form the polyurethane (PU)/fly ashes blend. It is evident that heavy metals can be encapsulated in PU foam, which was shown by the results of a toxicity characteristic leaching procedure (TCLP) test. After the tensile strength test, the elongation test, and the hardness test, the physical and chemical properties of the PU/fly ashes blend were acceptable for commercial applications. Meanwhile, based on the leaching criteria of Environmental Protection Administration (EPA) of Taiwan, comparing the new PU/fly ashes blended with 18% fly ashes and PU/fly ashes blended in ambience at room temperature for 1 year's time revealed both blends to function effectively in the tests. The results from the weatherability test illustrate that the maximum percentage of fly ashes allowed in the blends was 18%. Therefore, fly ashes blended with PU foam was a new and effective recycle method to deal with MSW. We aim to evaluate the processing parameters to create a new application option of the fly ashes so that the treatment loading of residual can be reduced.