Application of surface chemical functionalized cellulose nanocrystals to improve the performance of UF adhesives used in wood based composites - MDF type

• Published in: Carbohydrate polymers 2019-02, Vol.206, p.11-20
• Main Authors: Khanjanzadeh, Hossein, Behrooz, Rabi, Bahramifar, Nader, Pinkl, Stefan, Gindl-Altmutter, Wolfgang
• Format: Article
• Language: English
• Subjects: APTES; CNC; Formaldehyde emission; Mechanical properties; Urea formaldehyde
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2018.10.115

•Surface modification of CNC was performed using APTES.•MDF panels were produced with UF resins reinforced with the modified-CNC.•Formaldehyde emission of MDF panels decreased with increasing amount of modified-CNC.•The addition of modified-CNC improved the mechanical properties of MDF panels.•Better physical properties resulted with modified-CNC addition. The aim of this research was to investigate the effect of functionalized cellulose nanocrystals (CNC) on the performance of urea-formaldehyde (UF) adhesive for the production of medium density fiberboard (MDF). Surface modification of CNC was performed using 3-Aminopropyltriethoxysilane (APTES). Some physical and thermal properties of reinforced and neat UF as well as formaldehyde emission and some mechanical (modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond strength (IB)) and physical properties (thickness swelling (TS) and water absorption (WA)) of the resulting MDF panels were determined. Based on the results, upon incorporation of modified CNC to the system, solid content, density, viscosity and free formaldehyde of UF adhesives decreased while gel time increased. Depending on addition of the modified CNC loading in the panels, the formaldehyde emission values varied from 11% to 17% lower than the panels made from neat UF. In comparison to the control samples, panels made with UF containing 2% modified CNC had 29.3% and 38.2% higher MOR and MOE respectively.