Environment-friendly wood fibre composite with high bonding strength and water resistance

Abstract

With the growing depletion of wood-based materials and concerns over emissions of formaldehyde from traditional wood fibre composites, there is a desire for environment-friendly binders. Herein, we report a green wood fibre composite with specific bonding strength and water resistance that is superior to a commercial system by using wood fibres and chitosan-based adhesives. When the mass ratio of solid content in the adhesive and absolute dry wood fibres was 3%, the bonding strength and water resistance of the wood fibre composite reached the optimal level, which was significantly improved over that of wood fibre composites without adhesive and completely met the requirements of the Chinese national standard GB/T 11718-2009. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) characterizations revealed that the excellent performance of the binder might partly be due to the amide linkages and hydrogen bonding between wood fibres and the chitosan-based adhesive. We believe that this strategy could open new insights into the design of environment-friendly wood fibre composites with high bonding strength and water resistance for multifunctional applications.

Improvement of the Weather Resistance of a Selective Laser-Sintered Copolyester–Limestone Composite Using UV-326 and UV-328

“…The XPS analysis was employed to identify the surface chemistry of SLS parts. Figure 7 shows the C1s spectra with high-resolution scans for P/L, P/L-6, and P/L-8 before and after accelerated aging for 30 d. The spectra were deconvoluted into four components for all of the specimens: C1 (C-C, C-H), C2 (C-O), C3 (C=O/O-C-O), and C4 (O-C=O) [ 20 ]. Compared to the initial P/L, the C/1 of P/L after accelerated aging for 30 d decreased a lot, while C2, C3, C4, and the O/C ratio increased ( Table 3 ).…”

Modification of the properties of wood via combination of treatments: Freeze treatment and silicone oil heat treatment - Part 2

“…The intensity of diffraction peak at 34.62 o C was stable and may be interpreted as the glucan chains of cellulose that are largely unaffected [15]. Crystallinity is the major factor that influences the mechanical and dimensional properties of wood-based materials [16]. The influence of combined treatments on the components of the wood and on the crystallization behaviour of cellulose could be reflected through calculating the crystallinity index of the wood (Table 3).…”

“…On comparison with the untreated samples, freeze-silicone oil heat treated samples showed slightly increased crystallinity (Table 3). The degradation of hemicelluloses, lignin and extractives resulted in a relative increase in cellulose content, which could contribute to the relative increase in crystallinity [16]. It should be noted that both the hemicellulose and lignin has amorphous; while cellulose has both amorphous and crystalline regions.…”

A fully bio-based wood adhesive valorising hemicellulose-rich sidestreams from the pulp industry

“…26,27 Chitosan has shown promising results as binder in wood adhesives in several studies, mainly in combination with other components and only in small scale, using purified, well-defined, raw materials. [28][29][30][31][32][33][34][35][36][37] The present study, utilizing sidestreams from pulping in combination with chitosan, demonstrates a fully bio-based wood adhesive with the potential of large-scale production, and with properties on par, or superior to, commercial fossil-based counterparts. .…”