Achieving high-performance poly (styrene-b-ethylene-ranbutylene-b-styrene) nanocomposites with tannic acid functionalized graphene oxide

In this paper, graphene oxide (GO) was functionalized with tannic acid (TA), an easy-available and low-cost plant, on the GO surface through simple ultrasound-/shearing-assisted solution blending. The TA endows GO a stronger interfacial interaction with poly (styrene-b-ethylene-ran-butylene-b-styrene) (SEBS) and greatly improves the dispersion of GO in the SEBS, resulting in a much high efficiency of GO on improving the performance of the matrix. By adding 10 wt % of TA-GO (weight ratio of TA and GO = 2:1), the dielectric constant of SEBS matrix at 100 Hz reached up to 58.7, about 27-fold and 7-fold increment compared with that of neat SEBS and SEBS/GO nanocomposites, respectively. Moreover, compared with neat SEBS, the tensile strength, modulus and fracture toughness of SEBS/TA-GO nanocomposites with the addition of 0.5 wt% of TA-GO were enhanced by 122%, 91% and 107%, respectively. GO-induced firbous SEBS and microcrack formed around GO were found and proposed as the toughening and reinforcing mechanism of TA-GO in SEBS. This study not only provides a strategy to prepare high-performance SEBS nanocomposites, but also puts forward a facile, easy, low-cost and effective strategy to enhance the graphene-polymer interfacial interaction and improve the dispersion of graphene in the polymers.