Analysis of Bulk Dynamic Properties in Two-Layered Natural Rubber Vulcanisates

Two-layered vulcanisates were prepared from two rubbers with different dynamic properties, and the bulk dynamic properties of the layered rubber vulcanisates were assessed. The results reveal that the bulk dynamic properties are strongly dependent on a layer thickness ratio. For the specimens in which each layer has similar compressive modulus and dynamic properties, the relationship between the bulk dynamic properties and the layer thickness ratio obeys a rule of mixture. However, for the specimens in which each layer has a large difference in compressive modulus, some deviation from the rule of mixture towards the layer with relatively large deformability (i.e., the layer with relatively low compressive modulus) is observed.

Keywords:

• Natural rubber
• Layered vulcanisates
• Dynamic properties

ACKNOWLEDGMENTS

The financial support from the National Metal and Materials Technology Center (MTEC) and the Thailand Research Fund (TRF) are gratefully acknowledged.

Notes

^a N-tert-Butyl-2-Benzothiazole sulfenamide.

^b N-(1, 3-Dimethylbutyl)-N′-Phenyl-P-Phenylenediamine[24].

^a Determined from the Goodrich flexometer at a test frequency of 30 Hz.

^b Measured at compressive strain of 40%.