Mechanical Properties and Characterization of Natural Rubber Nanocomposites

K. Kueseng and K.I. Jacob
Institute of Science, Walailak University, TH

Keywords: single-walled carbon nanotubes, SiC nanoparticles, natural rubber, Raman spectroscopy, nanocomposites

Abstract:
Single-Walled Carbon Nanotubes (SWNT) and SiC nanoparticles were used to prepare natural rubber (NR) nanocomposites. Our first effort to achieve nanostructures in SWNT/NR and SiC/NR composites will be explained in detail. Nanocomposites were formed by incorporating nanoparticles in a polymer solution and subsequently evaporating the solvent. Using this technique, nanoparticles can be dispersed homogeneously in the NR matrix in an attempt to increase the mechanical properties of these nanocomposites. Mechanical test results show an increase in the initial modulus for up to 50% in relation to pure NR (see Figure 1). The mechanical properties of NR with 1.5 phr SiC nanoparticles appear to be superior to those of SWNT with the same filler content. In addition to mechanical testing, these nanocomposites were analyzed by the SEM and Raman spectroscopy techniques in order to understand the morphology of the resulting system. The Raman spectrum of the SWNT/NR is characterized by a strong band at 1595 cm-1 (G* mode - C-C stretching) and other two bands at 1300 cm-1 (D* mode-disorder induced) and 2590 cm-1 (second-order), see Figure 2 [1]. A shift of the 2590 cm-1 Raman band to the lower wavenumber was found after performing a cyclic testing to a SWNT/NR sample. Ageing another SWNT/NR specimen in distilled water for 30 days also provided a similar result (Figure 2). The Raman shift indicates the stress transfer from the NR matrix to the SWNT implying an existence of bonding at the interface [2]. In summary, a technique to prepare NR composites uniformly reinforced with nanoparticles was developed. The resulting composites showed significantly higher properties than the pristine NR.

Nanotech 2004 Conference Technical Program Abstract