Raffaele Longo

In the field of structural materials, there is a growing need to use new materials/components, which can be easily manufactured through energy‐saving production processes. The design of the new materials must guarantee improved mechanical and thermal performance or at least the preservation of the performance of current materials. This study deals with the kinetics and the curing reactions of a bi‐functional epoxy precursor, which can be cured using as hardener an anhydride. The system is able to reach a high curing degree and good mechanical performance, suitable for structural components. The curing process has been monitored using Fourier‐transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analysis. The FTIR results highlight high curing conversions also at low values of temperature.

This work deals with developing a self-healing resin designed for aeronautical and aerospace applications. The bifunctional epoxy precursor was suitably functionalized to enhance its toughness to realize good compatibilization with a rubber phase dispersed in the hosting epoxy resin. Subsequently, the resulting mixture was loaded with healing molecules. The effect of the temperature on the epoxy precursor’s functionalization process was deeply studied. Fourier trans-former infrared (FT-IR) spectroscopy and dynamic mechanical analyses (DMA) evidenced that the highest temperature (160 °C) allows for obtaining a bigger amount of rubber phase bonded to the matrix. Elastomeric domains of dimensions lower than 500–600 nanometers were found well distributed in the matrix. Self-healing efficiency evaluated with the tapered double cantilever beam (TDCB) method evidenced a healing efficiency for the system functionalized at 160 °C higher than 69% for all the explored fillers. The highest value was detected for the sample with DBA, for which 88% was found. The healing efficiency of the same sample functionalized at 120 °C was found to decrease to the value of 52%. These results evidence the relevant role of the amount and distribution of rubber domains into the resin for improving the resin’s dynamic properties. The adopted strategy allows for optimizing the self-healing performance.