Cellulose nanocrystals application in the urea-formaldehyde resin composite formulation

• Grant number: 20/00801-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2020
• End date: June 30, 2021
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Rafael Henriques Longaresi
• Grantee: Davi Alex Nogueira
• Host Institution: Centro de Ciências e Tecnologias para a Sustentabilidade (CCTS). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

Cellulose is the most abundant biopolymer in the world presenting an enormous chemical variability due to the functionalization of its hydroxyl groups. Furthermore, cellulose presents different morphologies that are found in a hierarchical structure constituent of the plants and can be presented in the form of fibers, microfibrils (MFC) and cellulose nanocrystals (CNC). Cellulose microfibrils and, in particular, cellulose nanocrystals have been studied in nanocomposites due to their biodegradability, low coefficient of thermal expansion, optical anisotropy, high elastic modulus (similar to steel and Kevlar), high aspect ratio and high surface area. The present project should employ CNCs as reinforcement material in a urea-formaldehyde (UF resin) polymeric matrix for the fabrication of a nanocomposite. CNCs will be extracted from the wood dust (sawdust) from residual logging production. UF resin has wide application in the wood industry in the production of plywood boards such as MDF (Medium Density Fiberboard). Thus, the nanocomposite thermal and mechanical properties are expected to be enhanced for application in the plywood production such as higher rigidity, lower water absorption, and higher thermal stability. Stress-strain, thermogravimetry (TGA) and dynamic-mechanical thermal analysis (DMTA) measurements will be performed for the mechanical and thermal characterization of the nanocomposite. Nanocomposite structure and topology will be evaluated by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) techniques. The theoretical mechanical behavior of the nanocomposite will be modeled from the Ouali and Halpin-Kardos models. (AU)