The present work has been focused on the mechanism of physical-chemical processes (abiotic) that promote as ultimate stage the biodegradation of full carbon backbone polymers, thus transforming these polymers in eco-compatible materials. In particular, the investigations undertaken in the present PhD thesis work was the evaluation of the rate of biodegradation of oxidized and degraded oxo-biodegradable polyolefin samples (PE, PP, PS) under aqueous, soil and compost conditions. Based on these criteria polyolefin (PE, PP and PS) film samples formulated with different pro-oxidant (type and content) based on transition metal organic salts able to promote oxidative degradation/biodegradation by abiotic and/or biotic actions have been ascertained into three tiers. Tier 1 Acceleration of samples aging in standard tests for both thermal and photo-oxidation processes and determination of the degree of abiotic degradation. Tier 2 Monitoring of the biodegradation of the pre-treated samples in respirometric apparatus. Tier 3 Assessment of interactions between polymeric materials and microbes and of any toxicity effect of the metabolized polymer fragments.