Progress in sustainability within the realm of designing new thermosetting materials

Identifier:  TDX:4314

Handle: https://hdl.handle.net/20.500.11797/TDX4314

Authors:  Roig Gibert, Adrià

Abstract:
Thermosetting materials, vital for applications demanding robust mechanical properties like automobiles and construction, encounter recycling challenges due to their irreversible, infusible and insoluble structure. This leads to substantial waste after their useful life, mainly ending up in landfills or incinerated, posing sustainability issues. This pressing concern highlights academia and industry's need to devise strategies for reducing waste accumulation and preserving the environment. Strategies like click chemistry, dual-curing, biomass-based monomers, and covalent adaptable networks (CANs) offer eco-conscious approaches for crafting sustainable thermosets. This study encompasses these strategies to design varied thermosetting materials, emphasizing in the sustainability approach. Chapter 3 introduces a dual-curing system via thermal epoxy-amine and thermal/photoinitiated methacrylate homopolymerization, yielding diverse highly crosslinked thermosets. Chapter 4 explores homopolymerization of commercial (meth)acrylates and thiol-epoxy dual-curing, adjusting initial formulation for tailored properties. Chapter 5 presents a renewable dual-curing process based on eugenol, glycerol, and pentaerythritol derivatives, using click thio-Michael and thiol-epoxy reactions for the preparation of thermosets with controlled properties. Chapter 6 showcases sustainable perspectives through biobased poly(acylhydrazone) CANs prepared from different biobased dihydrazides and a vanillin epoxy derivative and its dynamic behavior. Chapter 7 describes the synthesis of imine-containing polymers with fast relaxation rates and good recycling properties. Chapters 8 and 9 present dynamic materials from renewable resources and commercially available monomers, focusing on disulfide metathesis and creep resistance. Chapter 10 develops reversible vitrimeric adhesives that thanks to dynamic transesterification, allowing easy debonding and rebonding at high temperatures. The final chapter establishes a bio-based dual-curing system with sequential reactions, resulting in highly crosslinked materials with multiple dynamic bonds, demonstrating mechanical properties and recyclability.