Material PropertiesThe effect of dynamic vulcanization on the mechanical, dynamic mechanical and fatigue properties of TPV based on polypropylene and ground tire rubber

Thermoplastic elastomer blends consisting of 30% polypropylene and 70% ground rubber tire, pure or combined with virgin styrene-butadiene copolymer, were successfully prepared through a dynamic vulcanization process, involving dicumyl peroxide and N,N′-m-phenylene-bis-maleimide (BMI), in different proportions. The blends have shown excellent ultimate tensile strength and elongation at break, comparable with several others TPV systems, and also good reprocessing, which becomes useful for several potential applications. The blends were also characterized in terms of fatigue properties, morphology and dynamic mechanical properties. The tensile properties after fatigue stress decreased but this behavior was less significant for PP/GTR vulcanized blends. The effects of the dynamic vulcanization and the presence of GTR on the degree of crystallinity of the PP phase were also evaluated by differential scanning calorimetry analysis.