Chemical characteristics of thermo-hydrolytically recycled particles

• Published in: Bioresources 2020-05, Vol.15 (2), p.3774-3786
• Main Authors: Fu, Qilan, Wang, Xiang-Ming, Cloutier, Alain, Roussière, Fabrice
• Format: Article
• Language: English
• Subjects: Acids; Buffers; Chemical properties; Furniture; High temperature; Interfacial bonding; Manufacturing; Mechanical properties; Particle size distribution; pH effects; Polymers; Pretreatment; Recycling; Resins; Size distribution; Urea; Water treatment; Wood composites
• ISSN: 1930-2126; 1930-2126
• DOI: 10.15376/biores.15.2.3774-3786

Particles from waste laminated particleboards were recovered using various thermo-hydrolytic treatments. The size distribution and three main chemical properties, such as pH, buffer capacity, and nitrogen content of the control and resulting particles were determined. The effects of treatment temperature and duration on the chemical properties of recycled particles were investigated. The effects of the resulting particles on the gel time of urea-formaldehyde (UF) resin were also measured. The test results suggested that the pH of particles after hot water soaking pre-treatment and the different thermo-hydrolytic treatments increased to different extents, with the exception of the particles treated at 140 °C for 50 min and 160 °C for 20 min. The acid buffer capacity and base buffer capacity of particles treated at 140 °C for 50 min and 160 °C for 20 min had no statistical difference, but they were much higher than those of other types of treated particles. A high treatment temperature facilitated the decomposition of wood polymers and UF resin. Both temperature and treatment duration had significant effects on pH, acid buffer capacity, and base buffer capacity of wood particles. Wood particles recycled at a high temperature had a negative effect on the gel time of UF resin.