Nanocellulose functionalized with ethylenediamine as a modifier of urea-formaldehyde adhesive in particleboard production

The aim of the conducted research was to investigate the effect of introducing a nanocellulose (NC) functionalized with an ethylenediamine (EDA) to urea-formaldehyde (UF) adhesive on the properties of particleboard. The effectiveness of performed functionalization was confirmed using a Fourier transform infrared spectroscopy (FTIR) and amino groups quantification. Based on the outcomes of a thermogravimetric analysis and the measurements of a contact angle, it was found that the EDA-modified nanocellulose was characterized by improved thermal stability and reduced hydrophilicity. Moreover, the results of differential scanning calorimetry showed that the modification of the UF adhesive increased the enthalpy of the curing reaction, which indicates an increase in the UF adhesive reactivity. The effect was particularly distinct when the EDA-modified NC was applied. Modification of the UF adhesive also had a positive effect on the physical and mechanical properties of the produced single-layer particleboards. The applied functionalization with EDA allowed to increase the potential of NC in improving the internal bond, reducing thickness swelling and formaldehyde content of the manufactured boards. Overall, the use of 1% EDA-modified NC was selected as the optimal variant enabling the production of particleboards characterized by enhanced strength, improved water resistance and decreased formaldehyde content.