Novel composite materials from bulky wastes

The presented study aimed to investigate the possibility of producing novel composite materials with potential use in the construction and building sector from bulky wastes, particularly engineered wood and polyurethane (PU) foams from post-consumer furniture products. Simultaneous application of these materials could not only yield an efficient management approach for the furniture wastes but also provide auspicious features to the final composites resulting from the specific properties of particular components. The low apparent density of PU foams yields materials with reduced density and thus leads to a reduction in the share of adhesive resins, which are primarily responsible for the volatile organic compound emissions from engineered wood material. Reduced density and presence of pores inside the structure may enhance thermal insulation performance, as reported by Hýsek et al., who applied recycled PU mattress foam to produce insulation panels with wheat husks. Mao et al. pointed to the superior mechanical performance of particleboards in which polymeric isocyanate binder was partially substituted with micronized PU foam powders. In the presented case, multiple composite particleboards with varying contents of engineered wood and PU foam wastes have been prepared by compression molding technology with the application of innovative binder composed of diisocyanate and inorganic salts, whose in situ decomposition led to the gas generation providing porous structure of final composites, and produced compounds strengthening the interfacial bonding inside the material. The impact of applied formulations and manufacturing procedures on the structure (density, porosity, chemical structure), mechanical (static and dynamic), acoustic, and thermal insulation performance of resulting composites have been explored. Presented results indicated that by the proper engineering of materials' composition and preparation, the compromise between the weight, mechanical performance and other functionalities required by the particular applications can be found. Generally, it was proven that the proposed method of bulky waste management may yield materials with performance comparable to the commercially available solutions, which could provide novel ways for its efficient utilization.