Modified nanocrystalline cellulose from two kinds of modifiers used for improving formaldehyde emission and bonding strength of urea-formaldehyde resin adhesive

In this study, nanocrystalline cellulose (NCC) was used for increasing the bonding strength of urea-formaldehyde (UF) resin adhesive, with a reduction of formaldehyde (HCHO) emissions. The surface of NCC was modified by 3-aminpropyltriethoxysilane (APTES) and 3-methacryloxypropyltrimethoxysilane (MPS) for the lack of compatibility with UF resin adhesive. The modified NCC was characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TG), and wetting property. HCHO emission and bonding strength of the UF resin adhesive with modified NCC were tested according to Chinese National Standards GB/T 17657-1999 and GB/T 9846-2004. The results of XRD, TG, and wetting property from NCC modified by APTES showed more significant improvements than that from NCC modified by MPS. The HCHO emission of UF resin adhesive with 1.5% NCC modified by APTES decreased by 53.2% and bonding strength increased by 23.6%, while the results from the NCC modified by MPS were 21.3% and 7.0%, respectively.