Novel symmetrically substituted 2,3,9,10,16, 17,23,24-octa(p-methylphenoxy)phthalocyanines [(p-methylphenoxy)(8)PcM (3-5, where Pc is phthalocyanine and M is H-2 or one of its metal complexes, Mg or Zn, respectively)] were synthesized and characterized as target precursors for the preparation of polypropylene (PP)/Pc composite films [PP/(p-methylphenoxy)(8)PcM (labeled I-III for composites with Pcs 3-5, respectively)]. We prepared the composites by embedding the Pcs into the PP using the cast method. The effects of c irradiation on the physicochemical properties of PP after the formation of the PP/(p-methylphenoxy)(8)PcM composite films (I-III) were studied. The structure of the prepared composite series (I-III) was characterized with Fourier transform infrared spectroscopy. For composite III, minor differences in the Fourier transform infrared spectra were observed after irradiation treatment; these occurred because the zinc Pc additives in the repeating units of composite III acted as stabilizing elements against c-irradiation-induced degradation because of the delocalization of excitation energy in the double and aromatic units and also because of the large ionic radius of Zn in composite III compared with those in composite II (containing Mg) and composite I (metal-free). (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 134-141, 2011