Polymer, 2018, vol 146pp. 31-41
Controlling dispersion and networking of particulate fillers in a polymer matrix is critical towards the development of high performance polymer composite. However, fabricating such a methodology at a large scale is challenging. Herein, we report an effective strategy, by which the dispersion, structure and networking behavior of a particulate filler like N-220 carbon black can be controlled in a polymer matrix. Strategically important, poly (styrene –co-butadiene) was taken as the model polymer, whereas expanded graphite was used as the dispersing agent. The composite prepared with the hybrid filler (xSG22) demonstrated better mechanical properties compared to the solo carbon black filled composite (xS22) at the same loading. The molecular parameters responsible for determining the mechanical properties were determined through theoretical studies. From the dynamic mechanical analysis and Payne effect, it was corroborated that xSG22 adopted percolating fractal network inside the polymer, whereas xS22 did not demonstrate such dispersion. The formation of the percolating network was further supported from the electrical conductivity measurements and from various microscopic studies. SAXS experiment provided an insight towards the fractal dimension and crosslink density. xSG22 demonstrated improved ice traction, wet grip and dry handling characters without compromising the rolling resistance compared to xS22. Such a methodology can be extended to a wide variety of plate like filler and carbon black system and study their effect where specific properties like ice traction, wet grip and dry handling are demanding.