Use of Irradiation in Plastic Wastes Disposal

The feasibility of utilizing irradiation to assist in plastic waste disposal was investigated. This was based on the observation that most plastic materials become brittle upon irradiation. Sheets of polyvinyl chloride and polyethylene were bombarded with 1.3 MeV electrons generated by a Van de Graaff accelerator. They were tensile-tested at room temperature. The strength of the plastic materials was substantially reduced by irradiation, and the ductility was completely eliminated upon irradiation of about 3 x 10¹⁶ e/cm² in polyvinyl chloride and 1 x 10¹⁶ e/cm² in high density polyethylene. Based on the present experimental results, it was estimated that to eliminate the ductility of 1 g of polyvinyl chloride the material would require irradiation for about 17 min using a 1,000 curie Sr⁸⁹ radiation source (assuming 100% efficiency). Thus, utilization of radiation sources for plastic waste treatment seems impractical for large quantities.