Development and Characterization of Sustainable Biocomposites from Wood Fibers, Spent Coffee Grounds, and Ammonium Lignosulfonate

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creativework.keywordsbiocomposite, lignosulfonate, physical and mechanical properties, spent coffee grounds, thermogravimetric analysis, wood fibers
creativework.publisherMultidisciplinary Digital Publishing Institute (MDPI)en
dc.contributor.authorSavov V.
dc.contributor.authorAntov P.
dc.contributor.authorKostadinova-Slaveva A.
dc.contributor.authorYusein J.
dc.contributor.authorDudeva V.
dc.contributor.authorTodorova E.
dc.contributor.authorPetrin S.
dc.date.accessioned2026-01-20T13:58:04Z
dc.date.accessioned2026-01-20T15:55:10Z
dc.date.available2026-01-20T13:58:04Z
dc.date.available2026-01-20T15:55:10Z
dc.date.issued2025-10-01
dc.description.abstractCoffee processing generates large volumes of spent coffee grounds (SCGs), which contain 30–40% hemicellulose, 8.6–13.3% cellulose, and 25–33% lignin, making them a promising lignin-rich filler for biocomposites. Conventional wood composites rely on urea-formaldehyde (UF), melamine–urea–formaldehyde (MUF), and phenol–formaldehyde resins (PF), which dominate 95% of the market. Although formaldehyde emissions from these resins can be mitigated through strict hygiene standards and technological measures, concerns remain due to their classification as category 1B carcinogens under EU regulations. In this study, fiber-based biocomposites were fabricated from thermomechanical wood fibers, SCGs, and ammonium lignosulfonate (ALS). SCGs and ALS were mixed in a 1:1 ratio and incorporated at 40–75% of the oven-dry fiber mass. Hot pressing was performed at 150 °C under 1.1–1.8 MPa to produce panels with a nominal density of 750 kg m−3, and we subsequently tested them for their physical properties (density, water absorption (WA), and thickness swelling (TS)), mechanical properties (modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond (IB) strength), and thermal behavior and biodegradation performance. A binder content of 50% yielded MOE ≈ 2707 N mm−2 and MOR ≈ 22.6 N mm−2, comparable to UF-bonded medium-density fiberboards (MDFs) for dry-use applications. Higher binder contents resulted in reduced strength and increased WA values. Thermogravimetric analysis (TGA/DTG) revealed an inorganic residue of 2.9–8.5% and slower burning compared to the UF-bonded panels. These results demonstrate that SCGs and ALS can be co-utilized as a renewable, formaldehyde-free adhesive system for manufacturing wood fiber composites, achieving adequate performance for value-added practical applications while advancing sustainable material development.
dc.identifier.doi10.3390/polym17192589
dc.identifier.issn2073-4360
dc.identifier.scopusSCOPUS_ID:105018803486en
dc.identifier.urihttps://rlib.uctm.edu/handle/123456789/1905
dc.language.isoen
dc.source.urihttps://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105018803486&origin=inward
dc.titleDevelopment and Characterization of Sustainable Biocomposites from Wood Fibers, Spent Coffee Grounds, and Ammonium Lignosulfonate
dc.typeArticle
oaire.citation.issue19
oaire.citation.volume17
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