Valorization of Cork Waste in Particleboard Production with Innovative Binder

Currently, in addition to plastic waste, electronic waste, or batteries, a robust emphasis is being placed on the efficient management of municipal waste, which people are producing more and more. One of the groups of municipal waste is bulky waste, i.e., waste that does not fit into commonly used garbage containers. This mainly includes furniture, upholstered goods, carpets, rugs, bicycles, or baby carriages. Simultaneously, the environmental awareness of the society is noticeably growing, which is expressed by the development of 9R Principle - Refuse, Rethink, Reduce, Reuse, Repair, Refurbish, Remanufacture, Repurpose, Recycle, Recover. All of these activities are aimed at extending the life of products and their parts, which represents a further step from a linear economy to a Circular Economy in relation to processes involving the efficient use of materials, such as recycling or energy recovery. Commonly applied energy production from waste is the lowest level of circularity. In the current situation, a favorable alternative, allowing to achieve both financial and environmental benefits, is to recycle bulky waste and use it in further production processes to reduce the consumption of primary and natural resources. Therefore, it is vital to look for opportunities for further use of this type of waste, enabling them to be kept in a loop, which will be an important step towards the Circular Economy. The presented study aimed to investigate the possibility of producing novel particleboards with potential use in the construction, building, or furniture sector from cork waste, particularly engineered wood and polyurethane (PU) foams from post-consumer furniture products. Materials have been prepared by compression molding technology with the application of innovative binder composed of diisocyanate and inorganic salt, 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 on the structure (density, porosity, chemical structure, surface wettability), mechanical (static and dynamic), and thermal insulation performance of resulting composites have been explored. Presented results indicated that by the proper engineering of materials' composition, 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.