The technique is based on a computational approach used by Van Lehn called the Conductor-like Screening Model for Realistic Solvents (COSMO-RS) to guide the process. COSMO-RS can calculate the solubility of target polymers in solvent mixtures at varying temperatures. This narrows down the number of potential solvents that could dissolve a polymer. The team can then experimentally explore the candidate solvents.
Van Lehn said, “This allows us to tackle these much more complex systems, which is necessary if you’re going to make a dent in the recycling world.”
The objective is to eventually develop a computational system that will allow scientists to discover solvent combinations to recycle a wide range of multilayer plastics. The group likewise plans to take a gander at the environmental effect of the solvents it uses and set up a green solvents database that will allow them to more readily balance the efficacy, cost, and environmental impact of various solvent systems.
The project stems from UW–Madison’s expertise in catalysis. For decades, the university’s chemical and biological engineering researchers have pioneered solvent-based reactions to convert biomass — like wood or agricultural waste — into useful chemicals or fuel precursors. Much of that expertise translates into solvent-based polymer recycling as well.