r2epoxy

Epoxy resins are thermoset polymer materials, very widely used in modern society. Epoxy adhesives, plastic parts made from epoxy resins, and epoxy-based fibre-reinforced polymer composites are found in all major economy sectors (e.g. construction, transport, food, energy, electronics, leisure) globally.  Epoxies show exceptional properties (adhesion, mechanical performance, chemical & thermal stability). However, due to the irreversible curing chemistry needed to form the thermoset polymer network, epoxies cannot be recycled, or re-shaped under heat, or re-processed/re-worked in any other way, or be repaired/self-repair after suffering any damage. The possibility of obtaining epoxy products with all their known performance attributes, and with added malleability/recyclability and therefore improved end-of-life properties would constitute a major breakthrough in plastics technology and recycling.

Target the design of novel epoxy polymer networks that combine the well-known and highly sought properties of epoxies, but at the same time are dynamic: possible to re-shape and re-process as thermoplastics. We aspire to realise such novel dynamic epoxy polymer networks by synthesising a range of suitable amine curing agents with a pre-existing dynamic bond in their structure. When using such novel dynamic epoxies as composite matrices, the composite laminates would not only be possible to re-shape and re-process, but also to recycle at their end-of-life: separate fibres from the epoxy polymer matrix, recover pristine fibres for subsequent reuse in composite manufacturing, and re-use the recovered matrix in appropriate applications (e.g. as an adhesive). The novelty of our approach relates to a universal modification strategy potentially applicable to any given epoxy resin, a large collection of amine cross-linker structures to match each different epoxy, and the option to tailor either cleavage of the dynamic bonds (for recycling) or exchange reactions between the dynamic bonds (for re-processing).