Electron Spin Resonanceon Hybrid Nanocomposites Based on Natural Rubber

Abstract

Electron spin resonance (ESR) was used as a new method to analyze the synergy between two nanofillers different by nature, form and rigidity dispersed in natural rubber matrix. Natural rubber (NR) nanocomposites loaded with fixed amount of carbon nanotubes (2 parts per hundred of rubber parts; phr) and various amounts of expanded organically modified montmorillonite (EOMt, 4-20 phr) were investigated. The dependence of the double integral of the resonance spectra on the amount of EOMt present in the natural rubber was established. Its decrease with an increaseof the amount of EOMt confirmed the synergy between these two nanofillers. Also DMA temperature sweep measurements were performed and the cluster-cluster aggregation (CCA) model was used to assess the apparent filler networking energy. The obtained results suggest that the presence of the EOMt above a critical amount strengthens the hybrid-filler networking.