Very High Frequency Dynamic Mechanical Properties of Rubbery Compounds in Light of Tyre Application an Assessment Using VHF 104 Analyser

Rubbery materials undergo deformation at sufficient magnitude and frequency during actual end use condition. In tyre ,the Wet grip is correlated at High frequency range (10 ⁴-10 ⁵ Hz) and Rolling resistance at Few hundred Hz. Conventional DMA is utilized to predict the viscoelastic attributes at high frequency range by using WLF equation. The master curve generated by this method is not smooth due to Thermo rheological complexity of Rubbery material.VHF 104 analyser works on transmissibility and vibration isolation principle which can be used to probe viscoelastic attributes up to Kilo hertz range. This increased frequency window of VHF 104 analyser can be effectively utilized to create a robust Master curve. Present paper investigates the contribution of various factors like Elastomer structure, cross link type and density, reinforcement potential, Filler dispersion on very high frequency dynamical mechanical properties. . VHF analysis of different types of elastomers reveals that elastomer can act as a transmitter or damper of energy depending on the applied frequency ratio (ω/ωn). VHF analysis also depicts that polysulfidic linkages has high damping ratio (ζ) than mono sulfidic linkages due to its dissipative nature. As increasing the reinforcement potential of rubber composites, the natural frequency (ωn) is shifted to higher frequency range and damping ratio (ζ) increases. Better filler dispersion enhances polymer-filler interaction and increases natural frequency (ωn) and decreases damping ratio (ζ).Validation of WLF equation has been done by comparing the Master curve generated from VHF 104 Analyser and DMA.Shift factor (a_T) dependence on temperature and frequency has been discussed.