A novel economically viable method of preparation of graphene-rubber masterbatch for its application in tyre compound

Abstract

Properties of rubber composites can be improved by the incorporation of graphene. However, it is practically not feasible to use graphene in tyre compound because of its high-cost and difficult to disperse it in the rubber matrix. The present study demonstrates the development of a novel, cost-effective method of manufacturing graphene-rubber masterbatch (GRMB). Aqueous dispersion of graphene (10 wt%) was prepared by high-speed ball milling (500 RPM for 7 h) of graphite in presence of surfactant (5% w/w with respect to graphite). The graphene thus produced was characterized through X-ray diffraction (XRD), Raman spectroscopy, and atomic force microscopy (AFM). The XRD results confirmed the exfoliation of graphitic layers, defect generation in graphene was identified from Raman spectroscopy and AFM image proved the formation of graphene sheets. The graphene dispersion thus produced was mixed with natural rubber (NR) latex using magnetic stirrer at 500 RPM for 3 h maintaining 15% of graphene in GRMB. After mixing, the mass was dried in a vacuum oven at 80 °C. After that 3.33 phr (parts per hundred parts of rubber by weight) of GRMB (0.5 phr graphene) was added in truck and bus radial (TBR) tyre tread compound. The addition of GRMB significantly improved tensile modulus (21.5%), tensile strength (3.8%), hardness (5.1%) and tear strength (17.4%) of the regular TBR tyre tread compound. In GRMB, graphene was in pre-dispersed form enabling easy dispersion in final tyre compound. The graphene thus produced was economically viable since no expensive materials, and complicated synthesis and purification methods were used.