PHYSICAL AND MECHANICAL PROPERTIES OF RIGID POLYURETHANE FAOMS MODIFIED WITH SELECTED FLAME RETARDANTS OR LAYERED SILICATES

The flame retardants: expandable graphite, decabromodiphenyloxid, triethylphosphate and nanofillers: natural montmoryllonite [MMT] - Nanofil (R) 116, natural MMT modified with a quaternary ammonium salt - Cloisite (R) 10A, synthetic layered silicate - Laponite (R) RD has been used in rigid polyurethane foams (PUFs). The influence of fillers amounts on processing parameters, physical-mechanical properties (compression strength, density, water absorption, brittleness, mass loss and volume change) and thermal properties (thermal stability and storage modulus in DMA methods) of such foams has been analysed. The morphology has been characterized by X-ray diffraction and scanning electron microscopy (SEM). The X-ray diffraction of the polyurethane nanocomposite foams has been indicated the partial exfoliation of the clay in the polyurethane matrix. The flame retardancy and the thermal stability of all polyurethane modified systems was improved by an addition of flame retardants or nanoclays. Best results, in comparison for pure polyurethane foam, was obtained for polyurethane modified with organically modified montmorillonite (Cloisite 10A).