Development and characterization of Bioblocks: a sustainable wood-based composite utilizing MDF residues, citric acid and polyols

The study investigated the production process and properties of a new wood-based material called Bioblocks. This sustainable composite is made from medium-density-fibreboard (MDF) residues, citric acid and either sorbitol or hexanediol. The process involves mixing in-water diluted chemicals with the MDF residues and curing the mixture in a laboratory oven to esterify the sorbitol and wood components with citric acid. A design of experiment was used to determine the influence and optima of the different process factors, and an optimised trial further investigated the material properties. The density distribution, compression strength, and TS after 24 h immersion in water according to EN 317 of the Bioblocks were tested. The first trial showed that mainly the amount of water added impacts the product’s properties. The optimised material achieved a sufficient density distribution with an average density of about 420 kg/m³, a compression strength of up to 3.5 N/mm², and a TS of about 2%. Therefore, Bioblocks are a promising natural material to use waste MDF and substitute fossil, unsustainable materials.