Upcycling of medium-density fiberboard and polyurethane foam wastes into novel composite materials

• Novel composite materials obtained from two types of bulky wastes • Composites from flexible polyurethane foams and medium-density fiberboards • Application of innovative binder composed of diisocyanate and inorganic salt • Structure and performance of composites driven by the binder composition • Method for the efficient utilization of main bulky waste streams While plastic and e-waste dominate public discourse, municipal waste, particularly bulky wastes pose a significant challenge due to their large-scale generation aligning with the enrichment of society. Their efficient collection and keeping in a loop should be considered among the priorities of municipal waste management. Herein, the presented work presents novel composite materials obtained from flexible polyurethane foams used as mattresses and medium-density fiberboards applied in furniture products. Composites have been prepared using compression molding, with the addition of an innovative binder composed of a diisocyanate and inorganic salt, whose in situ decomposition led to the gas generation providing the porous structure and strengthening the interfacial bonding inside the material. The impact of changes induced by the chemical interactions on the appearance, morphology, mechanical, thermal, acoustic and insulation performance of composites has been evaluated. Observed changes pointed to the auspicious conclusions on the further applications of the examined binder composition.