Investigations of Nitrile Rubber Composites Containing Imidazolium Ionic Liquids

Summary This work aimed to investigate the impact of hydrophobic imidazolium ionic liquids with alkyl chains of varying length attached to the cation imidazolium ring on the rheometric data, the mechanical, morphological, thermal and conductive properties of acrylonitrile‐butadiene rubber (NBR) composites. The presence of ionic liquids not only increased the conductivity (AC) of the composites but also influenced their curing behaviour and mechanical properties. A maximum conductivity of 8.9 · 10−8 S · cm−1 was achieved at room temperature in the NBR sample containing 15 phr (parts per hundred rubber) of 1‐hexyl‐3‐methylimidazolium bis(trifluoromethane‐ sulfone)imide (HMIM TFSI). Moreover, the presence of HMIM TFSI at 15 phr loading in the NBR composite contributed most significantly to the downward shift in the glass transition temperature (Tg) from ‐30 to −33 °C, indicating a plasticizing effect