Synergistic Effect of TNPP and Carbon Black in Weathered XLPE Materials

Carbon black is one of the most widely used and most effective ultraviolet (UV) light stabilizers for plastics applications. Several important segments of the plastics industry rely on carbon black for UV stabilization of weather-resistant products, including telecommunications, power cable jacketing, and plastic pipes. In this research work a combination of Trisnonylphospate (TNPP) antioxidant and different size carbon black were applied in crosslinked polyethylene (XLPE) to improve its wetherability. The primary reason for cross-linking polyethylene (PE) is to raise the thermal stability of the material under load. This substantially improves environmental stress crack resistance and resistance to slow crack growth. The results achieved of this additive package combination show a synergism effect and improved weatherability of electrical cable. Increased weathering lifetime was also achieved. Further, we were able to confirm in this work, that the size and quality of the carbon black dispersion in a XLPE samples is an important component of both the UV-resistance and mechanical properties of the finished plastic article. Incremental improvements of carbon black dispersion can positively influence the expected life of plastic articles. Mechanical testing and FTIR were used to detect degradation of the accelerated weathered XLPE samples. The morphological considerations of UV energy absorption and presents laboratory data demonstrating the link between dispersion and weatherability as well as between morphology and weatherability