The effect of carbon black on thermal antioxidants for polyethylene

Abstract

Abstract About 3% by weight of carbon black adequately protects polyethylene against photo‐oxidation and, under accelerated test conditions, slightly inhibits thermal oxidation. As a rule small amounts of organic antioxidants are also added to the polymer for optimum protection. Now many of the common phenolic and amine additives have been found to function much less effectively in polyethylene containing carbon black than in clear polymer. Loss of effectiveness is attributed to adsorption and/or decomposition of the antioxidant by both basic and acidic carbon black.