Frequency and temperature dependent viscoelastic properties of natural rubber and nitrile butadiene rubber at different temperatures for vibration damping applications: an experimental study

The study aims to evaluate the frequency and temperature-dependent viscoelastic properties of natural rubber (NR) and nitrile butadiene rubber (NBR) for vibration damping applications. The dynamic mechanical analysis (DMA) tests were conducted on NR and NBR at low frequencies, from room temperature to 112 °C. The experimental data were fitted using the generalized Maxwell model, and vibration tests were conducted to obtain dynamic properties such as natural frequencies, damping ratio, and quality factor. The loss factor for NR increased significantly above 80 °C, while for NBR, it decreased above 50 °C. At higher temperatures, both NR and NBR exhibited faster relaxation, but NR had a higher loss factor, indicating a better damping ability. The relaxation strength of NR increased above 60 °C, whereas that of NBR decreased, highlighting the differences in their damping abilities. NBR showed greater damping ability at the first natural frequency, while NR performed better at the second and third natural frequencies. According to the experimental findings, NR proves to be better suited for damping in high-temperature conditions, while NBR is more suitable for low-temperature damping applications. The relaxation modulus of NR is lower than that of NBR at lower temperatures, leading to a better damping performance for NR at higher temperatures. The study recommends using NR for high-temperature applications where high damping is required and NBR for low-temperature applications that require moderate damping.