The impact of carbon black morphology and dispersion on the weatherabilityof polyethylene

Carbon black is one of the most widely used and most effective ultraviolet (UIV) light stabilizers for plastics applications. Several important segmen ts of the plastics industry rely on carbon black for UV stabilization of we ather-resistant products, including telecommunications and power cable jack eting, plastic pipes, geosynthetic membranes and agricultural films. Recent research at Cabot Corporation confirms that the quality of the dispersion of the carbon black in a plastic medium (i.e. polyethylene) is an important component of both the UV-resistance and mechanical properties of the finis hed plastic article. There is a significant body of research into the linka ge between carbon black morphology, including particle size, and UV perform ance. There is also anecdotal evidence demonstrating the linkage between di spersion quality and overall weatherability. In this study, Cabot will demo nstrate that incremental improvements of carbon black dispersion can positi vely influence the expected life of plastic articles. With industry standar d carbon blacks as a reference point, Cabot documents the morphological con siderations of UV energy absorption and presents laboratory data demonstrat ing the link between dispersion and weatherability as well as between morph logy and weatherability.