Enhanced thermo‐mechanical properties of carbon fiber reinforced thermoresistant polymer, a blend of di‐functional epoxy bisphenol A and a tri‐functional epoxy Tactix 742

Abstract Fiber reinforced polymer composite structures are particularly vulnerable to high temperatures as their strength drastically reduces under elevated temperature conditions. Therefore, it is important to improve the thermal stability of such composite structures to expand their potential range of applications. In this study, the effect of mixing two epoxy monomers, DGEBA and Tactix 742, which are di‐ and tri‐functional, respectively, on the thermal stability of their composites is investigated. The thermo‐mechanical analysis of these composites revealed that the glass transition temperature rose from 123 to 229°C when Tactix 742 is increased from 25% to 75%. The thermal resistance property is attributed to a three‐dimensional crosslink network which is initiated by tri‐functional Tactix 742. However, the higher percentage of Tactix led to a reduction in strength, possibly due to decreased crystallinity and formed amorphous phase material. Subsequently, a tensile strength model was employed to assess the performance at elevated temperatures. It was shown that a matrix with a mix of di‐ and tri‐functional monomers is highly promising for manufacturing thermoresistant polymeric composites with robust mechanical properties, thereby expanding their potential applications across various engineering fields such as civil and construction industries. Highlights A thermoresistant matrix by blending di‐ and tri‐functional epoxy monomers. Improved thermo‐mechanical properties and increased glass transition temperature of fiber reinforced composites. Mechanical performance of carbon fiber reinforced composites at elevated temperatures. Validated a model to estimate the tensile strengths of the composites at elevated temperatures.