This grant will enable the exploration of a new science-based technology for a novel continuous process enabling the reprocessing of crosslinked polyethylene, a material used extensively today in products such as plastic bags, hot and cold water pipes, wire and cable insulation, storage tanks and many injection molded parts. Most crosslinked materials cannot be reprocessed because the network molecular structure that gives them such attractive properties is very difficult to decrosslink without destroying the polymer. In fact, today most of these discarded products are simply burned for their limited caloric value. These novel ultrasonically aided extrusion processes have the potential to produce material of sufficient quality and integrity to enable it to be reprocessed into new products. The research team will study the ultrasonic extrusion and fabrication, as well as the structure and properties of the decrosslinked polyethylene materials and will establish the process models and identify the mechanisms allowing for the prediction of the optimal conditions of ultrasonic processing and scale up of the process.
If successful, the results of this research will lead to the manufacture of new materials and products from waste crosslinked polyethylenes for use in many of the same applications. The societal impact would be a significant solid waste reduction in landfills. The theoretical modeling and computer simulations of the ultrasonic treatment of these crosslinked polyethylenes will contribute to the optimization of the process and design of new ultrasonic extruders. The technology could also be applicable to a broader class of crosslinked polymers beyond polyethylene.