The use of a hybrid consisting of tubular clay and graphene as a reinforcement for elastomers

The reinforcement of plastic polymers by using the synergetic effects of two different fillers has sparked great interest, however, few works have been devoted to elastomers. In the present work, a tannic acid functionalized graphene (TAG) aqueous dispersion was prepared and hybridized with tubular clay, halloysite nanotubes (HNTs), to prepare a hybrid colloid (HNTs-TAG). The driving force for the hybridization was shown to be the specific interactions (hydrogen bonding and bridged bidentate bonding) between the catechols on TAG and the alumina/siloxane surfaces of HNTs. The obtained hybrid colloid was then co-coagulated with styrene-butadiene rubber (SBR) emulsion to prepare elastomeric composites. The results showed that a 3D hybrid filler network consisting of HNTs and TAG was developed and served as a novel networked reinforcement in the SBR matrix. The formed hybrid filler network, together with the enhanced interfacial interaction, is considered to be responsible for the significant synergetic effects in the improvement of the modulus and strength of the composites.