Thermal aging analysis of carbon black and silica filled natural rubber based on terahertz dielectric spectroscopy

Two main types commonly used modified natural rubber, carbon black filled and silica filled, are studied using terahertz (THz) dielectric spectroscopic technique during their thermal aging. Standard artificial thermal aging is applied to the tailor-made rubber samples and THz time-domain spectroscopy (THz-TDS) system is employed to measure their complex THz dielectric permittivity at regular intervals during the entire span of thermal aging. Experimental results show that there are obvious differences in THz dielectric permittivity of carbon-black-filled and silica-filled natural rubber. And more importantly, THz technology can distinguish the rubber samples' aging states, and the rules between THz dielectric permittivity and the thermal aging states are different for these two kinds of modified natural rubber.