Optimal processing conditions of a bio-based epoxy synthesized from vanillyl alcohol

Abstract

This work provides a comprehensive thermomechanical and rheological characterization of a high-performance epoxy resin synthesized from a vanillin derivative, vanillyl alcohol. The study includes a complete analysis of the curing and decomposition kinetics that enabled a Time-Temperature-Transformation plot accounting for gelation, vitrification, and resin degradation to be developed. These plots allow one to determine the optimal time and temperature processing conditions that will yield the best mechanical properties. Kinetic predictions and experimental results showed that this resin can be cured at room temperature in just a few hours, forming a solid gelled glass. Enhanced mechanical properties are achieved by post-curing the resin at temperatures above Tg∞ = 85.4 °C. With a dynamic storage modulus of 2.7 GPa, this bio-based resin proves to be a sustainable alternative to fossil-based resins whose primary source is the ever-prevalent bisphenol A diglycidyl ether. Thermal oxidation is the main cause of the mechanical deterioration at high temperatures, as revealed by FTIR spectroscopy.