Exploring novel high temperature matrix resin composites for advanced engineering applications

The continuous push for performance retention at high-temperatures and improved strength-to-weight ratios has been a crucial factor in developing novel materials for propulsion materials and wider aerospace applications. Advanced composite materials offer superior toughness and lower specific densities when compared to conventional metal alloys. Additionally, retention of mechanical properties at elevated temperature indicates their potential widespread implementation in aerospace applications. Much research has been conducted to develop thermoset resin systems with enhanced thermal and moisture durability properties. The employment of these advanced composite systems in propulsion components would lead to reductions in both component mass and cooling requirements, consequently lowering fuel consumption and exhaust gas emissions.

There has been specific interest into cyanate esters due to their tuneable viscosity properties for resin infusion and high glass transition temperatures, making them suitable for a range of applications. Previous research has incorporated small amounts of polydimethylsiloxane into cyanate ester networks, to reduce moisture absorption and enhance toughness. Susceptibility to water leading to moisture uptake is a key limitation to the widespread application of advanced composites in aerospace and propulsion applications, so a similar approach of incorporating a siloxane into the resin matrix was adopted. Optimisation of the resin composition aims to achieve a balance between moisture resistance, degree of polymerisation, and network architecture; which are crucial factors for the material's performance and ensuring their use in long-term, oxidising environments. However, poor compatibility between siloxanes and cyanate esters has proven to be a historical challenge, often resulting in significant phase separation during manufacture. Although there is some understanding of the cyanate ester resins of this nature, their behaviour when combined with higher concentrations of silicon-containing species remains unexplored, offering a degree of novelty to this body of research. This investigation aims to evaluate the resin system's suitability for practical high-temperature aerospace applications, bridging the gap between laboratory research and real-world implementation. Novel material systems for high-temperature applications are crucial for advancing modern aerospace technologies. Characterising these materials' mechanical and thermal behaviour will be essential for understanding their performance in harsh environments.