Filler effect on the degradation of γ-processed PLA/vinyl POSS hybrid

Highlights: • The presence of vinyl POSS enhances the thermal and radiation resistance of PLA. • The vinyl POSS filler turns with priority the degradation of PLA onto monomer instead of oxidation of free radicals. • The penetration of water and the attack of fungi are more advanced in irradiated PLA hybrid samples. - Abstract: The stability of poly(lactic acid) on which the product lifetime depends can be enhanced by the addition of vinyl POSS (vinyl polyhedral oligomeric silsequioxane) nanoparticles. PLA hybrids were subjected to accelerated degradation by γ-irradiation and analyzed by chemiluminescence, DSC, water swelling and biodegradability. The results of kinetic investigation for degradative oxidation allow the calculation of the activation energies required for accelerated ageing whose values depend on the degradation state. The cage effect and the participation of vinyl units would be the reliable explanations for the improvement of oxidation strength. The hybrid system containing 3 wt% vinyl POSS particles displays suitable increases oxidation induction times and diminished oxidation rates according due the involvement of vinyl units and the contribution of POSS to radical scavenging. The choice of vinyl POSS is an excellent alternative for the modification of PLA destined to long term applications based on the notable filler contribution to its adequate scavenging action and the narrowing pathway to lactides.