Nanodiamond-based PP/EPDM thermoplastic elastomer composites: Microstructure,tribo-dynamic,and thermal properties

Attempts have been made for the first time to employ graphitized nanodiamond with the cage-like structure to prepare thermoplastic elastomer (TPE) nanocomposites based on polypropylene (PP) and ethylene-propylene-diene rubber (EPDM), with improved tribo-dynamic properties. Samples were prepared via melt mixing process, and maleated polypropylene (PP-g-MAH) was used to promote the interfacial interactions between the components and partitioning of nanodiamond particles in polymer phases. Microstructure characterization revealed significant reduction in the size of EPDM droplets if nanodiamond particles are preferentially wetted by the polypropylene phase. Nanoindentation and scratch tests performed on the surface of prepared nanocomposites exhibited enhanced surface stiffness and scratch resistance. Rheomechanical spectroscopy (RMS) and dynamic mechanical analysis (DMTA) showed enhanced melt elasticity for the interfacially compatibilized nanocomposites, which is attributed to the antiplasticizing characteristics of the caged shape nanodiamond particles. More interestingly, nanodiamond particles exhibited plasticizing behavior for the nanocomposite in molten state. All interfacially compatibilized nanodiamond composites showed enhanced thermal resistivity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012