New foamy materials obtained by adding industrial wastes in epoxy and polyurethane matrix were fabricated. The aim to investigate about a new way to recycle waste materials from leather tanning process was in addition to the purpose to study new systems also under sandwich form for civil applications. The material used as filler in the matrix, labelled as “wet blue”, was under powder form and its disposing of represents an environmental problem since the presence of chromium(III) used in the tanning processes that in particular environmental conditions change in the dangerous hexavalent state. For this reason, first of all chemical analysis were done: no chrome release was found, avoiding any problems about toxic aspects. Wet blue was, first, added to epoxy matrix and unusual foaming was noted with a consequent decrease in weight. The specimens were then mechanically and physically characterised. Then, adding “wet blue” in different percentages to polyurethane, that usually already foam, resulted in a sensible increase in the porosity and, so, in the volume with a consequent density reduction up to 50% and a sensible increase in the speed reaction. From studies carried out up to now, the possibility to obtain low specific weight materials without sensible mechanical properties degradation, was observed. A consequence of an increase of volume is also a reduction in costs since the gain in resin weight. Sandwiches were obtained gluing polycarbonate sheets as skin and specimens for a wide mechanical and thermal characterization were cut from the realised panels following the ASTM standards. The results of the tests were compared with the simple polyurethane core performances. A change in mechanical and physics polymer properties was observed even if not always in terms of improvement, but a general possibility to obtain low specific weight materials without sensible properties degradation, was observed. Positive results were reached in correspondence of some fillers combinations in terms of different percentages about impact absorption energy, acoustic and thermal absorption coefficient.
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