New insight into structure-property relationships of natural rubber and styrene-butadiene rubber nanocomposites filled with MWCNT

The outstanding properties of carbon nanotubes (CNT) have generated a lot of interest at a scientist and industrial level. CNT have attracted great attention due to their exceptional mechanical, electrical and thermal properties and also for their large aspect ratio, that is, small size and higher surface area. On this regard, CNT-rubber composites have been prepared, using natural rubber (NR) and styrene butadiene rubber (SBR) as matrices, and varying the amount of filler from 0 to 20 phr. In order to understand and optimize the properties of these materials, a fundamental and systematic study has been done with the aim of quantifying the relative contribution of the different factors that determine the reinforcing effect of these nanoparticles. The results obtained from the different characterizations of the composites (study of the electrical and mechanical properties, Payne effect, dynamical mechanical analysis, low field NMR and swelling experiments) reveal a good filler-rubber interaction, a high reinforcement effect, and an increase on the electrical conductivity of the compounds. However, all these improvements are limited by the detrimental effect of the CNT on the vulcanization process.

Pilar Bernal Ortega, Mª Mar Bernal a, Antonio González Jiménez b, Pilar Posadas, Rodrigo Navarro, Juan López Valentín
a Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, 15121, Alessandria, Italy
b Materials Science and Engineering Area, Rey Juan Carlos University, C/Tulipán s/n, 28933, Móstoles, Madrid, Spain