Effects of Ferric Stearate on Thermo-Oxidative Stabilization Efficiency of Phosphite Antioxidants in High Density Polyethylene

Polyethylene (PE) is extensively used as packaging material due to its ideal physical properties, easy production and low cost [1, 2]. However, PE requires some kinds of stabilization for every stage of its life cycle in order to prevent catastrophic results of thermo-oxidative degradation which may occur during both melt processing and service life of the polymer artifacts [3]. This is normally achieved by addition of suitableantioxidants. On the other hand, this polymer doesn’t undergo biodegradation within a realistic period of time (10 years), due to its chemical inertness and its high molecular weight. Theproblem could be solved by addition of some pro-oxidant additives which accelerate oxidation process under influenceof heat or sunlight. The polymer can completely degrade and then be easily digested by the microbial enzymes produced by the organisms. As antioxidants and pro-oxidants play opposite roles in the polymer, it is worthwhile to evaluate the overall activity of the two additives when they are used together in thepolymer. So, in this article, for the first time, we reported influence of ferric stearate (FeSt) as a commercially used prooxidantadditive on thermo-oxidative stabilization efficiency of Irgafos 168, a widely used phosphite antioxidant, in HDPE in both melt and solid states.