Vitrimerization of Renewable Macromolecules and Nanoparticles: Bio-Based Materials Assembled via Dynamic Covalent Chemistry

• Grant number: 23/06914-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2023
• End date: June 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Camila Alves de Rezende
• Grantee: Sayeny de Ávila Gonçalves
• 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

Abstract

Vitrimers are polymeric materials with networks formed by associative dynamic covalent bonds that can be broken or reestablished under specific conditions. Vitrimers combine the remarkable chemical stability and mechanical properties of thermosets with the easy (re)processability of thermoplastics. Additionally, this type of material presents unique functionalities such as self-healing capability, adhesion, and shape memory. In this project, our aim is to extend this approach, introduced for synthetic polymers, to biosourced polymeric colloids, with the ultimate goal of assembling solid-state materials that deliver good physical-mechanical performance and can be fully reprocessed after use. The primary targets are nanocelluloses and nanochitins, given both the outstanding performance of their higher-order, solid-state constructs, and the poor mechanical recyclability of such materials, prevented by extensive hornification. Our endeavor will rely on the dynamic covalent toolbox by introducing and activating bond shuffling mechanisms on functionalized cellulose and chitin nanocrystals. These systems will involve vicinal tricarbonyl moieties as side chains that can be crosslinked by diols, polyols, and aromatic amines, or polymers from natural carboxylic acids. In both cases, dynamic networks thermally activated will be originated. Finally, the biobased vitrimers will be shaped into various morphologies (e.g., gels, films, parts, solid foams, etc.) that will then be investigated in terms of performance and mechanical recyclability.