Thermo-Mechanical, Physico-Chemical, Morphological, and Fire Characteristics of Eco-Friendly Particleboard Manufactured with Phosphorylated Lignin Addition

Lignin, lignosulfonate, and synthesized phosphorylated lignosulfonate were introduced as green fillers in citric acid-sucrose adhesives for bonding particleboard fabricated from areca leaf sheath (ALS). The characteristics of particleboards were compared to that of ultralow emitting formaldehyde (ULEF-UF). The fillers derived from Eucalyptus spp. kraft-lignin were added for flame retardancy enhancement. 10% of each lignin and modified lignin was added into the ULEF-UF and citric acid-sucrose bonded particleboards. Analyses applied to particleboards included thermal characteristics, X-ray diffraction analysis (XRD), morphological properties, Fourier transform infrared spectroscopy (FTIR), as well as physical, mechanical, and fire resistance characteristics of the laboratory-fabricated particleboards. Lignin and modified lignin resulted in improved thermal stability of the composites bonded with ULEF-UF while the improvement in the particleboard bonded with citric acid-sucrose was not significant. The introduction of filler exerted a higher influence on the UF-bonded particleboards compared to composites fabricated with citric acid-sucrose. Generally, the presence of lignin, lignosulfonate, and phosphorylated lignosulfonate enhanced the mechanical strength of the ULEF-bonded particleboards, although their dimensional stability has deteriorated. Markedly, the use of lignin and lignosulfonate enhanced the fire resistance of the particleboards produced with lower observed weight loss. All laboratory particleboards exhibited satisfactory fire resistance, attaining a V-0 rating in according to the UL-94 standard.