Antioxidant Activity Assisted by Modified Particle Surface in POSS/EPDM Hybrids

The presented results prove the stabilization activity of modified POSS particles in the thermal and radiochemical degrading EPDM. Various mono- or di-substituents (-CH3, -OCH3, -F, -Cl) assist the delay of oxidative degradation by the electronic interactions of free radicals inside the free volume of polyhedral oligomeric silsequioxanes (POSS) with substituents placed on the outer particle surface. The stabilization of EPDM/modified POSS patterns is characterized by chemiluminescence, FTIR spectroscopy and thermogravimetric analysis. The concern of each formulation is individually defined by the accumulation of oxygen-containing configurations, which depicts the degree of conversion for free radicals into degradation products. The efficiency ranks of substituents based on the surface effects are conclusive in respect with POSS molecular compositions. The performance of protection against oxidation is evident on the high temperature range and the advanced exposure to the action of γ-radiation. Meanwhile the damaging effect of γ-irradiation on the inorganic phase is characterized by XRD and SEM assays.