Effect of Polyether Sulfone Resin on Micromorphology, Thermal, Mechanical, and Dielectric Properties of Epoxy-Bismaleimide Composite Material.

In this study, 4,4′-diaminodiphenylmethane bismaleimide (BMI) was used as the matrix and epoxy resin (EP) and polyether sulfone (PES) were used as the toughening agent. PES/EP-BMI two-phase composites were prepared; they could be applied in more fields. The SEM results and energy spectrum analysis show a strong interaction between PES and EP-BMI molecules, and the surface of the two phases is fuzzy. PES dispersed uniformly in the EP-BMI matrix as the dispersed phase. The interface among phases is blurred and shows a mutual penetrating phenomenon. Furthermore, the cross-section of cracks is rough, and the directions change. This is a typical ductile fracture morphology. The highest bending strength and impact strength of PES/EP-BMI composite material are 144.9 MPa and 19.7 kJ/m², 41.2% and 90% increases copmared with those of EP-BMI matrix resin, respectively, when the content of PES is 4 wt%. Moreover, the decomposition temperature of the composite reaches 407°C, 9°C higher than that of EP-BMI. However, excess PES has a negative effect on the thermal decomposition temperature. The addition of PES increases the dielectric constant and dielectric loss of composites though they increase only slightly. The comprehensive properties of composites are at their best when the content of PES is 4 wt%. Overall, this study facilitates the applications of PES/EP-BMI composites in a broad range of fields. [ABSTRACT FROM AUTHOR]