RADIATION TECHNOLOGY IN THE LIGHT OF POLYMER WASTE RECYCLING

Abstract

Polymer pollution transcends national boundaries and threatens both human health and the environment. Despite efforts for efficient reuse of polymer waste, the majority of it accumulates in landfills and dumps or is mismanaged and is being dispersed in the environment. The application of ionizing radiation techniques could serve to reprocess and recycle polymer waste. Using a radiation source (gamma, electron beam or X-ray) to irradiate post-consumer plastics enhances their recyclability and facilitates their transformation into new products. Application of radiation technology is promising because it is not a novel one. Irradiated polymers could be found all around, from vehicle tires to hot water pipes and food packaging. Idea is to use irradiation applying different dose rates to gain reform and restructure polymer structure, with the aim to improve its recyclability and reduce the amount of polymer waste. The use of electron beam irradiation to form bridges between polymer strands refers to the process of cross-linking. Polymers degradation occurs after radiation is applied in the opposite way through chain scission, in that process polymers are cut up or ‘degraded’. Radiation can also induce an electric charge on the surface of plastics, making it easier to sort plastic waste more accurately. This improves both the volume and the number of times the waste can be recycled, such as with thermoplastics, which can be melted and reshaped repeatedly. Radiation technology can drive the economic potential of plastic upcycling by enabling the production of upscaled secondary products, like wood-plastic composites (WPC), from plastic waste, rather than downscaled alternatives.