(403b) Molecular Recycling of Multilayer Plastic Films Via Delamination

40% of all plastic is used in packaging, with a major fraction of this in the form of films. Most plastic films comprise multiple layers that impart desirable functionality (e.g., oxygen or moisture barriers, labels). Multilayer films are not mechanically recycled. Multilayer films can be processed via pyrolysis, the most common among chemical recycling processes, this, however, involves the break-down of polymers into fuel or chemical feedstock, resulting in undesirable greenhouse gas (GHG) emissions. Plastics recycling research in our group utilizes physical, solvent-based processes whereby polymer chains do not break. This constitutes true recycling, as the recovered polymer is the same as the staring material.

The objective of this project is to develop solvent-based processes to deconstruct flexible multilayer plastic films while leaving intact (in its solid form) the main component polyolefins. Specifically, we develop strategies based on delamination for separating individual polymers from multilayer packaging materials, we recover solid (undissolved) polyolefins via gravity separation, and perform a preliminary techno-economic analysis of the whole process.

The solvent-based multilayer film delamination process developed in this project is environmentally responsible on the basis of low energy usage and GHG emissions. The recovered polyolefins, following appropriate processing, can replace primary materials without loss of properties or performance and, hence, meet demand by customers and corporations to incorporate recycled plastics into products.