Functionalized cellulose nanocrystals for enhanced wood protection: Synthesis, characterization, and performance

This study developed eco-friendly protective materials for wood preservation, focusing on enhancing fungal decay resistance, insect damage prevention, and improving physical and mechanical properties. The research examined the penetration of cellulose nanocrystals (CNCs) and their functionalized compounds into wood tissue, evaluating their impact on poplar wood. Methodology included optimizing CNC production through acid hydrolysis, testing various temperature and time combinations. CNCs were then functionalized with Poly(dimethylsiloxane)-bis(3-aminopropyl) terminated (PDMS-NH), copper hydroxide, zinc oxide, and silver nanoparticles. Characterization techniques such as AFM, TEM, ESEM, XRD, FTIR, and μ-Raman spectroscopy analyzed CNCs and their derivatives. Wood samples were impregnated with CNCs and functionalized CNCs using pressure and vacuum treatments, then tested for weight gain, durability against white rot (Trametes versicolor) and brown rot (Coniophora puteana) fungi, resistance to insect attack (Trichoferus holosericeus), leaching resistance, and mechanical properties. Key findings included successful optimization of CNC production and functionalization, improved resistance against decay fungi (especially with CNC3/Cu treatment), elevating durability classification from "non-durable" to "low durability". However, treatments showed limited effectiveness against insect infestation. Leaching resistance varied among treatments, with CNC3/PDMS-NH performing best. Mechanical properties, particularly modulus of elasticity, improved significantly with CNC3 impregnation, especially in less degraded wood samples. The study contributes to eco-friendly wood protection systems development, demonstrating functionalized CNCs' potential to enhance wood durability and mechanical properties. Further research is needed to improve insect resistance and optimize the leaching performance of CNC-based treatments, paving the way for more sustainable wood preservation methods.