Improvement of nanosilica effects on the performance of mechanically processed styrene-butadiene rubber by rational hybridization with nanodiamond

Abstract

Hybrid nanoparticle comprising of nanosilica (NS) and nanodiamond (ND), denoted by [email protected], was synthesized by a two-step chemistry route and then incorporated into styrene-butadiene rubber (SBR) at low concentrations up to 5 phr by a two-roll mill. Physical hybrids of NS and ND, i.e., ND&NS, with a weight ratio similar to chemical hybrid (80:20 for NS:ND), were also incorporated into SBR. Field emission scanning electron microscopy observations revealed very fine dispersion of nanoparticles in the case of physical hybrids (ND&NS). In contrast, agglomerations and aggregation of nanoparticles were evidenced for [email protected] Tensile and dynamic mechanical analyses exhibited a higher reinforcing effect of hybrid nanoparticles with respect to single nanoparticles; however, ND&NS showed even better performance compared with [email protected] due to better filler-rubber interaction caused by improved filler dispersion. So, tensile strength, elastic modulus, and elongation at break of unfilled SBR increased about 23 %, 40 %, and 110 %, respectively, in the case of ND&NS. It was also realized that the incorporation of [email protected] and ND&NS, both at 5phr, enhanced the thermal conductivity of SBR by around 46 % and 31 %, respectively, with slightly better influence of [email protected] on thermal conductivity due to the improvement of the phonon energy transfer mechanism in this case.