Weatherability of polypropylene/waste tire dust blends: Effects of trans‐polyoctylene rubber and dynamic vulcanization

Abstract

AbstractTwo series of polypropylene (PP)‐based blends containing waste tire dust (WTD) from scrap tires were naturally weathered. From investigations of specimens after 3‐month and 6‐month weathering periods, the overall indication was that blends with trans‐polyoctylene rubber (TOR) and sulfur dynamic vulcanization (PP/WTDT‐SDV) resisted the deleterious effects of atmospheric factors better than the blends without TOR and dynamic vulcanization (PP/WTD). Tensile test results showed that PP/WTDT‐SDV blends exhibited higher tensile strength and elongation at break than PP/WTD blends. The PP/WTDT‐SDV blends also recorded higher retention values of tensile strength and elongation at break than PP/WTD blends. An increment in the Young's modulus of PP/WTD blends was noticed, however, after both exposure periods. The morphology of the fracture surfaces showed that less WTDT‐SDV than WTD was removed from the PP matrix, a result indicating the presence of improved interfacial adhesion in PP/WTDT‐SDV blends. Micrographs of exposed surfaces showed the formation of easily removed layers on the surface of PP/WTDT‐SDV, which might act as a protective covering and resist the deleterious effects of weathering on the internal parts of the PP/WTDT‐SDV blends. Thermograms showed that the melting temperatures of the exposed PP/WTDT‐SDV specimens were higher than those of PP/WTD samples after both outdoor exposures. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers.