Modification of flexible polyurethane foams by the addition of natural origin fillers

A series of flexible polyurethane foams (FPFs) with the addition of substrates from renewable resources were prepared, in order to investigate the influence of these fillers on the foam's properties. For this purpose, FPFs were synthesized with the addition of walnut shells and hazelnut shells. Thermogravimetric Analysis (TGA) was used to assess the influence of these filler on thermal stability and degradation processes of polyurethane foams. Phase transitions in tested foams were analyzed using Differential Scanning Calorimetry (DSC) and Dynamical Mechanical Analysis (DMA). Fourier Transformed Infrared Spectroscopy (FTIR) was carried out, in order to assess the influence of tested fillers on chemical structure of FPFs. Moreover, a series of physical (apparent density) and mechanical (hardness, flexibility, irreversible strain) measurements were carried out, in order to assess the influence of this type of modification on the properties of polyurethane foams. Results of these measurements indicate that it is possible to prepare FPFs with the addition of fillers from renewable resources, with improve thermal stability and desired physical and mechanical properties.