Novel metallophthalocyanines [M: Co (II), Cu (II), Zn (II), Mn (II)] bearing eight peripheral 2,6-di-tert-buthylphenol groups were successfully synthesized. The new products were studied by FTIR, 1H NMR, MADLI-TOF, UV/VIS spectral data and thermogravimetric analysis. The aggregation behavior of the new phthalocyanines was investigated in different solvents and concentrations. In addition, the antioxidant activities were analyzed through radical scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH). All the new compounds had radical scavenging activity higher than polymer's commercial antioxidant and the highest DPPH activity was obtained from phthalocyanine copper (II). Moreover, the thermooxidative stability of polypropylene (PP) and high density polyethylene (HDPE) with the new antioxidants were assessed by the measurements of the oxidation induction time (OIT), differential scanning calorimetry (DSC) test and melt flow index (MFI) analysis. The results showed that the newly synthesized phthalocyanine complexes could effectively inhibit the oxidation degradation of PP and HDPE.
