Silane Coupled E-Glass Fiber Reinforced Bismaleimide-Epoxy-Rochelle Salt Composites for High Dielectric Applications

A high performance bismaleimide (BMI)-epoxy-Rochelle salt (RS) composites reinforced with E-glass fiber (EGF) as well as silane coated unidirectional E-glass fiber (SC-EGF) were developed. The composite loaded with 2 wt.% of RS filler demonstrated maximum increment in dielectric constant as well as in mechanical properties. Composite with 3 wt.% of RS filler exhibited high dielectric strength indicating their adaptability for high voltage insulating applications. Dielectric constants and dielectric loss of the fabricated composites measured at higher frequencies (in GHz) using Vector Network Analyzer at room temperature was found to be highest for the BMI-Epoxy composite with 1 wt.% filler. Among the composites, the reinforced with SC-EGF exhibited significant increase in mechanical properties attributing to the interaction between matrix and silane functional groups on the glass fiber as evident through IR spectroscopy. The developed composite exhibiting low dielectric loss and high dielectric permittivity at room temperature can be applied in high dielectric applications.