Distribution variation of carbon black in tensile-tested rubbers estimated by terahertz time-domain spectroscopy

The dependence of a carbon black (CB) dispersion in a tensile-tested specimen of a vulcanized rubber on the compounding ratio of CB was evaluated by terahertz time-domain spectroscopy (THz-TDS). The near broken-out section of the specimens were investigated by THz-TDS, and the distribution of the absorbance in the THz regime, which directly affected by the CB dispersion, was investigated. It was found that the THz image of the CB dispersion in the samples showed a biased distribution between the fixed side and the pulled side of the tensile-tested specimens. It was also found that the difference of the CB dispersion of the both sides was decreased with the CB ratio.