Design of self-healing composite materials. Intelligent interphases characterization at nano and micrometric scale
Supervisors: CARRIERE Pascal, BERLIOZ Sophie, FAHS Armand
Epoxy resins have drawn the attention of many industries due to their versatility in numerous domains, from adhesives to polymer matrices with composites, becoming the object of large researches. Despite their versatility, day by day the markets need new lightweight, sustainable and high-performance materials. To confront these challenges, researchers have proved that nanoparticles incorporation improves polymer matrix performance, for instance, natural fibers like Nano Fibrillated Cellulose (NFC). Moreover, vitrimer materials have been presented as a new kind of crosslinked material with self-healing and reprocessing properties, desirable behavior to extend the lifetime of a product. In order to respond to the market demands, the elaboration of epoxy resins based on a vitrimer system with NFC incorporation could satisfy demands such as a high-performance eco-friendly material. Nevertheless the nature hygroscopic of NFC could decrease the mechanical properties of the composite, functionalization is a strategy well known to prevent it. Silanes functionalization is an easy and eco-friendly way to modify NFC surface.
The aim of this work is to study the impact of reinforcement by nanofibers pristine and modified on the exchangeable crosslink properties of the vitrimer nanocomposites. This study includes a strategy of NFC incorporation into an epoxy resin based on a vitrimer system and the evaluation of mechanical properties, the activation energy and the topology freezing transition temperature by stress relaxation experiments. The data obtained could provide enough information to build and propose a new stress relaxation model which could describe more precisely its behavior.