(570c) Production of Environmentally-Sustainable Bio-Composite for Coating Material Using Lignocellulosic Biomass

Discarded biomass in nature can be transformed into valuable eco-friendly products. Additionally, enhancing the value of naturally abundant lignocellulosic resources (including agricultural residues, wood, energy crops, and other industrial resources) can help mitigate environmental issues stemming from excessive use of fossil fuels. Cellulose is a vital and abundant natural biopolymer resource that can be broken down into various types of nanocellulose, such as cellulose nanocrystals (CNCs), cellulose nanowhiskers (CNWs), and cellulose nanofibers (CNFs). To achieve this, biomass undergoes physical and chemical pretreatment processes and is combined with various polymers to produce biodegradable and environmentally friendly films and coatings.

In this study, lignin content was controlled using alkali and organic solvent acid pretreatment methods on oak wood. Lignin-containing cellulose nanocrystals (LCNCs) were synthesized through physical and acid hydrolysis processes. LCNCs with varying lignin contents were introduced into a PVA matrix at different ratios to produce nano-composite films, which were then tested for water solubility, water absorption, and oil resistance.

The water solubility of PVA-LC films decreased to 61.78%, while PVA-LCNF films decreased to 38.16%. Oil resistance increased from grade 1 to grade 4. Particularly, with nano-lignocellulose containing 9.7 wt% lignin at a ratio of 2:1 (PVA), the Cobb value decreased from 23.58 g/m² to 15.68 g/m², and water resistance improved by 33.5%. The decrease in solubility and Cobb absorption values of the composite materials, along with the increase in oil resistance grades, were proportional to the increased amount of retained lignin. These results indicate that retaining lignin is advantageous for enhancing the properties of composite materials.