Performance of a phenolic antioxidant introduced by different procedures into polyethylene containing dispersed fillers

The performance of Irganox 1010 phenolic antioxidant was studied in relation to the procedure of its introduction into a stock of the polymer and dispersed filler powders. Three procedures were used for introducing the antioxidant: the antioxidant was deposited onto the surface of filler (procedure I) or polymer powder (procedure II) particles prior to mixing the components, or it was deposited after mixing the polymer and filler powders (procedure III). We studied mixtures with an inert filler (aluminum oxide) and with fillers active in polymer oxidation and regeneration of the phenolic antioxidant (dispersed zinc, zinc oxide). The film samples for the studies were prepared from powder stocks by hot pressing. The antioxidant performance was evaluated by the induction period of oxidation, which was determined from the time dependences of accumulation of carbonyl groups in the polymer structure.