| Abstract: | Compressive stress–strain properties of closed-cell microcellular EPDM rubber vulcanizates with and without a filler were studied with the variation of density. For filler variation studies, silica and carbon black (N330) were used. With a decrease in density, the stress–strain curve for microcellular EPDM behaves differently from that for the solid vulcanizates: The curve rises steeply when cell breakdown occurs. The compressive stress–strain properties are found to depend on the strain rate. The compression set at constant stress increases with decreasing density. The energy-absorption behavior was studied from the compressive stress–strain properties. The efficiency, E, and ideality, I, parameters were also determined as they are useful for the evaluation of closed-cell microcellular rubber as a cushioning and packaging material. These parameters were plotted against stress to find the maximum efficiency and maximum ideality region which will make these materials suitable for cushioning or packaging applications. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:263–269, 1998 |
