Mechanical and thermal properties of modified bismaleimide matrices toughened by polyetherimides and polyimide

Thermal and mechanical properties such as GIC (critical strain energy release rate), KIC (critical stress intensity factor), tensile, and flexural strength of bismaleimide (BMI) matrix toughened by commercially available polyetherimides (Ultem 1000P, Siltem STM 1700, and Extem VH1003) and polyimide P84 were investigated. In case of various contents, polyetherimides soluble in BMI phase separation was observed. The influence of the toughener amount on the mechanical properties of the matrices was studied. It was shown that Ultem and Siltem had a more significant influence on the GIC and KIC parameters than the more thermally stable P84 and Extem.