Evaluation of Durability of Elastomer by Dynamic Viscoelasticity
Naoki AIHARA, Masanori HANSAKA, Naoto MIFUNE
Elastomer (rubber) is used at many positions on the railway. Evaluating durability
of elastomer is important for safety. In order to evaluate degradation of elastomer,
it is effective to measure its dynamic viscoelastic properties; viscosity, elasticity
and plasticity. Especially, loss tangent (tan delta)is a convenient coefficient to know
changing of viscosity and elasticity easily. So we exposed rubber specimens outdoors
and in accelerated chambers. After exposure, the specimens were measured for
temperature dependence on dynamic viscoelastic properties. Measuring methods are
compulsive vibration method and torsion pendulum method. Measured tan delta curves were
analyzed according to Arrhenius' formula. Moreover, in order to evaluate plasticity
of rubber, we calculated weak physical bonds of tested specimen. From these results, we
showed initial degradation process of elastomer and evaluation of degradation quantitatively.