# Eugenol and Chavicol-Based Polyamides from Synthesis to Degradation: Moving Towards Closing the Circle

## TL;DR

This paper presents a sustainable approach to creating and recycling polyamides using natural compounds eugenol and chavicol.

## Contribution

The study introduces a solvent-free synthesis and closed-loop recycling method for polyamides derived from natural phenolic compounds.

## Key findings

- Polyamides made from eugenol and chavicol showed varied thermal properties and high stability.
- The polymers could be efficiently depolymerized under alkaline conditions for recycling.
- Recovered monomers can be reused in new polymer synthesis, promoting sustainability.

## Abstract

A new series of polyamides (PAs) employing two phenolic natural compounds as starting materials, eugenol and chavicol, has been successfully prepared. The synthesis was carried out through a solvent-free protocol using the environmentally friendly organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-3-ene (TBD). The obtained materials have been properly characterized. Moreover, the prepared materials, all of them amorphous, showed a wide range of transition temperatures (Tgs) depending on the structure of the diester counterpart used in the polymerization reaction. In addition, the influence of the methoxy group present in eugenol on the thermal properties of the resulting polyamides was studied. The synthesized polyamides demonstrated excellent thermal stability, high hydrophobicity, and great dimensional integrity. Furthermore, the obtained polymers could be depolymerized under alkaline hydrolysis conditions to yield, with good to excellent recovery ratios, the corresponding starting diamine monomer, which could eventually be used in the synthesis of new polymers. Closed-loop chemical recycling emerges as a sustainable alternative to conventional end-of-life management strategies for discarded polymers, while also constituting a promising pathway to mitigate the accumulation of polyamide (PA) waste.