Synthesis of the ionic liquid 1,2-dimethyl-3-butylimidazole bromide salt and its application in phenolic-formaldehyde-resin-based conductive materials

Herein, the ionic liquid 1,2-dimethyl-3-butylimidazole bromide salt ([DMBIm]Br) was synthesized and its chemical structure was characterized via Fourier transform infrared and ¹H nuclear magnetic resonance spectroscopies. Moreover, to improve the electrical property of the phenolic formaldehyde (PF) resin, PF/[DMBIm]Br systems were prepared via a melt blending and compression–curing process. Furthermore, the effect of [DMBIm]Br content on the thermal stabilities, mechanical properties, electrical properties, and morphologies of the systems was investigated. The thermal stability of the systems increased with [DMBIm]Br addition. The impact strength of the systems improved with increasing [DMBIm]Br content. Additionally, the volume resistance of the systems significantly decreased from 1.02 × 10⁹ to 1.64 × 10⁷ Ω with increasing [DMBIm]Br content from 0 to 1 wt%.