Accelerator adsorption onto carbon nanotubes surface affects the vulcanization process of styrene-butadiene rubber composites

DE FALCO, A; MARZOCCA, A.J; CORCUERA, M A,; EZEIZA, A; MONDRAGON IÑAKI,; RUBIOLO, G.H.; GOYANES, SILVIA

JOURNAL OF APPLIED POLYMER SCIENCE

Elsevier

Año: 2009 vol. 113 p. 2851 - 2857

0021-8995

Multi-walled carbon nanotubes (MWCNT) filled styrene-butadiene rubber (SBR)  composites were prepared by incorporating MWCNT in a SBR/toluene solution and subsequently evaporating the solvent. These composites have shown a significant improvement in Young’s modulus and tensile strength respect to SBR gum without sacrificing high elongation at break. However, this improvement is less than  xpected at the higher filler content. Then, the influence of low concentrations of MWCNT on the vulcanization process of the SBR composites was studied by means of rheometer torque curves, swelling measurements, differential scanning calorimeter (DSC) analysis and Fourier transform infrared (FT-IR) spectroscopy. Also, their thermal degradation was studied by thermo-gravimetric analysis (TGA). It has been noticed that MWCNT affect the cure kinetics of SBR gum matrix reducing all parameters, i.e, the total heat rate and order of the reaction, scorch delay,  aximum torque and crosslink density. This effect increases as MWCNT content does and it was attributed to the adsorption of the accelerator employed in the vulcanization (N-tert-butyl-benzothiazole-2-sulfenamide) onto the MWCNT surface. composites were prepared by incorporating MWCNT in a SBR/toluene solution and subsequently evaporating the solvent. These composites have shown a significant improvement in Young’s modulus and tensile strength respect to SBR gum without sacrificing high elongation at break. However, this improvement is less than  xpected at the higher filler content. Then, the influence of low concentrations of MWCNT on the vulcanization process of the SBR composites was studied by means of rheometer torque curves, swelling measurements, differential scanning calorimeter (DSC) analysis and Fourier transform infrared (FT-IR) spectroscopy. Also, their thermal degradation was studied by thermo-gravimetric analysis (TGA). It has been noticed that MWCNT affect the cure kinetics of SBR gum matrix reducing all parameters, i.e, the total heat rate and order of the reaction, scorch delay,  aximum torque and crosslink density. This effect increases as MWCNT content does and it was attributed to the adsorption of the accelerator employed in the vulcanization (N-tert-butyl-benzothiazole-2-sulfenamide) onto the MWCNT surface.