Influence of photo-oxidation on the performance and soil degradation of oxo- and biodegradable polymer-based items for agricultural applications

The examination of the aging behavior of polymers, blends, composites, items, etc. under different environmental conditions is a priority issue for assessing the possible applications and establishing the lifetime. In agriculture, plastic items (mulch films, irrigation tubes, etc.) are widely used and subjected to solar UV exposure that can induce photo-oxidation on macromolecular chains. Therefore, weathering under outdoor conditions and accelerated degradation tests are performed for simulating aging processes during the lifetime of materials and select appropriate stabilizers to be used. In the last decades, oxo- and biodegradable polymers have been investigated and used in agricultural items. The influence of photooxidation or outdoor weathering on their structures, performance and biodegradation behavior in soil has been evaluated. This review aims to provide an overview of the studies focused on the effects of photo-degradation processes on chemical-physical properties and degradation in soil of oxo- and biodegradable polymers or items designed for agricultural purpose, including an outline of the available standards. Additionally, a comparison between the behaviors induced by photo-oxidation of the two different families of degradable polymers used in agricultural plastic items is carried out.