Reprocessable and natural polymeric networks based on dynamic covalent bonds between cellulose nanofibers

• Grant number: 22/05465-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2022
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Camila Alves de Rezende
• Grantee: Thais Cardoso de Oliveira
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 21/12071-6 - Tailoring colloids through supramolecular interactions: from fundamentals to applications, AP.TEM
• Associated scholarship(s): 25/10394-3 - Microscopy and rheological studies to characterize the dynamical properties of colloidal networks based on transamination dynamic bonds between cellulose nanofibrils, BE.EP.DR

Abstract

This project proposes manufacturing structured materials (e.g., hydrogels, organogels, and aerogels) based on exchangeable dynamic covalent bonds between Cellulose Nanofibers (CNF), enabling the material's mechanical reinforcement, also allowing its recyclability and re-processability. These "cellulose vitrimers" combine properties from the two main polymeric classes: thermoplastic's re-processability and thermoset's high mechanical resistance. Furthermore, CNF's use as a base for developing this material may implement natural fiber's intrinsic properties in vitrimer's chemistry, such as non-toxicity and renewability. The experimental strategy to enable exchangeable covalent links into CNF is to prepare the nanofiber with carboxylic groups on its surface, followed by its functionalization with vicinal tricarbonyl compounds, which can create dynamic covalent bonds between the fibers when in diols, polyols, and aromatic amines' presence. Moreover, this innovative project can effectively grant the development of a new class of materials with enhanced mechanical properties, recyclability, and shape memory that can be extended through the complex structured materials and gels' field, being also valuable for biomaterials, adhesives, and coatings development. (AU)