A Review of Oxo-Biodegradable Polymers: Approaches and Challenges
Subject Areas :
1 - amirkabir
Keywords: Polyolefin, Oxo-biodegradable, Oxidation,
Abstract :
The production and consumption of plastics, particularly polyolefins such as polyethylene and polypropylene, have significantly increased in recent decades due to their desirable properties, including high chemical stability, suitable mechanical strength, and cost-effectiveness. However, this surge has led to serious environmental concerns, as polyolefins, due to their nonpolar structure and high molecular weight, are highly resistant to degradation in natural environments and can persist for hundreds of years. Consequently, developing strategies to enhance the degradability of these materials has become crucial. Various approaches have been proposed to improve the biodegradability of polymers, including blending polyolefins with natural polymers, incorporating oxo-biodegradable additives, pro-oxidants, and employing physical processes like ultraviolet radiation. Oxo-biodegradable additives accelerate polymer oxidation and modify their molecular structure, enhancing non-biological degradation and converting the polymers into simpler compounds that are more readily absorbed by nature. These additives are generally categorized into two types: organo-metallic compounds, such as iron and manganese, and non-metallic compounds, such as peroxides. Additionally, the use of natural polymers like starch, one of the most widely used polysaccharides, is common in blending with polyolefins. In Iran, the use of natural polymers and oxo-biodegradable additives has expanded due to easier accessibility and lower costs. However, the use of oxo-biodegradable materials also poses certain environmental challenges, such as incomplete biodegradation and recycling issues. This article explores industrial strategies for improving polymer biodegradability and provides an overview of research conducted in this field, along with relevant standards and associated challenges.