Polypropylene–waste ground rubber tire powder microcellular composites: Effect of processing variables on morphology and physico‐mechanical properties

Microcellular composites made from polypropylene and waste ground rubber tire powder using azodicarbonamide as chemical blowing agent have been investigated. A small quantity of SEBS‐g‐MA has been added as compatibilizer. The effect of variation in processing variables such as pressure, heating time, and operating variables such as blowing agent and crosslinker concentrations have been investigated to establish a relationship between the structure and morphology of the microcellular composite and ultimate performance characteristics such as tensile strength, tear strength, and elongation at break. The results indicate that both processing and operating variables have tremendous effect on the morphological features such as average, minimum, and maximum cell size as observed from scanning electron microscopy. POLYM. COMPOS., 2008.