Novel Energy and Cost Saving Polypropylene Stabilization via Addition of Antioxidant into Polymerization System

Abstract Polypropylene powder stability was evaluated by means of biaxially-oriented film processing, where the powder were prepared by using Ziegler catalyst in the presence of aluminum phenoxide derived from 3-(3,5-di- t -butyl-4- hydroxyphenyl)-N-octadecylpropionamide (AO-1) and triethylaluminum. Despite the lower concentration of antioxidant (ca. 560 ppm), the powder exhibited excellent stability compared with commercial film grade pellet including antioxidants of over 1000 ppm. Half amount of loading was found to be sufficient in the case of AO-1 phenoxide added into polymerization system. This indicates that cost saving of antioxidant due to the reduction of loading level can be achieved by the method. Thus, the method used the AO-1 phenoxide in the polymerization system is effective and economical technology.