Aramid pulp with physisorbed imidazolium ionic liquids for solvent-casted enhanced styrene-butadiene rubber composites

Poly-p-phenyleneterephthalamide is a broadly used aramid for the strengthening of materials. Nevertheless, its relatively inert surface is an obstacle for obtaining composites with enhanced properties. In this work, three ionic liquids (IL) were investigated as compatibilizers in the preparation of styrene-butadiene rubber (SBR)-aramid pulp composites. The composites were characterized using hardness and tensile tests, swelling, differential scanning calorimetry, and thermal gravimetric analysis, and also scanning electron microscopy. Aramid pulp treated with IL showed more fibrillation than the untreated pulp. The best characteristics were found for the composite with 5 phr of aramid pulp-1 wt % of physisorbed IL, which showed the lowest swelling degree compared to the IL-free SBR-aramid composite (341% and 410%, respectively) and the highest tensile strength (2.48 MPa), 340% superior to that of SBR (0.73 MPa), and 25% superior to the IL-free SBR-aramid composite (2.05 MPa). Confirming the potential of imidazolium IL to be used as compatibilizers in SBR-aramid composites. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46693.