Novel approach to rubber reinforcement by silica based nanofiller

The aim of this work is to study a spheroidal phyllosilicate, namely Halloysite NanoTubes (HNTs), as a possible reinforcing filler for tyre applications. HNT is a 1:1 alumino-silicate with a unique combination of tubular nanostructure. It has natural availability, rich functionality, good biocompatibility and high mechanical strength. However, HNTs are poorly compatible with the elastomers due to their hydrophilic character and the low concentration of functional groups on the external surface. In order to favor both the filler-polymer interaction and the particle dispersion in the rubber matrix, we investigated an effective method to increase the hydroxyl group density on the HNT surface, through controlled basic treatment. Moreover HNTs were functionalized with silane coupling agents to improve the compatibility with rubber. Modified nanotubes were used by ex-situ blending to prepare Styrene Butadiene Rubber nanocomposites. Morphological, spectroscopic and thermal analyses were performed for a complete characterization of the modified HNTs and their nanocomposites. The dynamic mechanical properties were evaluated and compared to those obtained by using pristine HNTs. The preliminary results revealed that HNT can act as a promising filler