The woodworking industry generates a great amount of bark which has not yet found a wider industrial application. None of the previously conducted research has considered oak bark application (which is one of the most often processed wood species in Poland) as a filler for wood adhesives. Moreover, no studies have determined the properties of bark containing melamine-urea-formaldehyde resin (MUF), which increasingly replaces pure urea-formaldehyde adhesives. Thus, the aim of the study was to determine the possibility of grinded oak bark application as a filler for MUF adhesive in plywood manufacturing. The chemical composition of oak bark was evaluated. Properties of liquid resins, such as viscosity, gel time, pH, and solid content, were determined. Chemical interaction between the filler and resin was assessed with using Fourier-transform infrared (FTIR) spectroscopy. Plywood panels manufactured using MUF adhesive filled with different bark concentrations (10%, 15%, 20%, 25%) were tested in terms of such properties as formaldehyde release and bonding quality. Studies have shown an improvement in liquid resin properties. The course of FTIR spectra did not explain the chemical interaction between the polymer and the filler. The addition of oak bark at a concentration of 15% made it possible to produce plywood panels characterized by reduced formaldehyde release and improved bonding quality.

It can be found that reaction mechanisms and interactions between wood and organosilicone compounds have not been sufficiently explored. The aim of the study was to determine bonds formed between either cellulose or lignin and methyltrimethoxysilane (MTMOS) during a catalytic silanization reaction. Silanization was performed in the presence of two catalysts of a diverse mechanism of functionalization: aluminum acetylacetonate (Al(acac)3) and acetic acid (AcOH). For this purpose, FT-IR, 13C and 29Si NMR techniques were used. Cellulose silanization efficiency without a catalyst was unlikely. Lignin undergoes a silanization reaction with alkoxysilanes much easier than cellulose. The results showed new bonds between biopolymers and the silanising agent. The new bonds were confirmed by signals at the FT-IR spectra, e.g., 770 cm−1 and 1270 cm−1 (Si–CH3), and at the NMR signal coming from the T1, T2 and T3 structures. Efficiency of reaction was confirmed by atomic absorption spectroscopy (AAS) analysis.

The aim of the study was to investigate the effect of nanocellulose (cellulose nanocrystals [NCC]) addition to urea‐formaldehyde (UF) resin on the properties of plywood and the possibility of reducing resin spread rate in plywood production. The studies have shown the increase in viscosity of experimental adhesive mixture in comparison with reference one. On the basis of the bonding quality results, it was concluded that the NCC‐reinforcement led to significant improvement in bonding quality of plywood. Moreover, values of bending strength (modulus of rupture) and modulus of elasticity also increased because of the cellulosic nanoparticles introduction. The positive effect of NCC addition on the properties of plywood allowed the reduction of resin spread rate by 50 g/m2 and maintaining equally good strength as reference panels. The modification with nanocellulose itself did not lead to a decrease of free formaldehyde content. However, allowing the reduction of adhesive application led to a slight decrease in the amount of emitted formaldehyde.

This study examined the effect of applying cellulose nanoparticles as a filling material for phenol-formaldehyde (PF) resin in the process of manufacturing water-resistant plywood. Based on investigations that concerned the rheological behavior of resin mixture containing various amounts of nanofiller, the modification of resin resulted in a major increase of viscosity. Although Fourier transform infrared spectroscopy did not fully explain the effect of modification on the chemical structure of the adhesive, there was a noticeable improvement in the morphology of cured nanocellulose-reinforced resin. Based on the bonding quality results, the optimum amount of nanocellulose was 3 PBW (parts by weight) per 100 PBW of resin and it allowed the achievement of a notable increase in shear strength values. Moreover, introduction of cellulosic nanoparticles had a positive effect on mechanical properties such as bending strength and modulus of elasticity. In summary, the research showed that it is possible to apply nanocellulose as a modifier for the adhesives in the process of manufacturing water-resistant plywood.