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The versatility and affordability of multilayer plastic films have created a large demand for them. 1, are any number of tie layers, wet bond adhesives, or additives (such as TiO 2) that may be present in small quantities compared with the principal resin fractions. Adding to the complexity of these materials, although not shown explicitly in Fig. The following are examples: Polyethylene (PE) is a flexible material that is often used as a moisture barrier in packaging materials for medical and consumer goods ethylene vinyl alcohol (EVOH) is an oxygen barrier commonly found in food packaging materials polyethylene terephthalate (PET) is an effective gas and moisture barrier that imparts rigidness and strength and is ubiquitous in single-use plastic water bottles ( 3). 1, are constituted by distinct layers of heteropolymers such as polyolefins and polyesters, with each layer selected to contribute a corresponding property advantage to the bulk material, depending on the application ( 2).

These complex materials, represented schematically in Fig. Multilayer plastic films are ubiquitous in the flexible and rigid plastic packaging industry ( 1). We show that the STRAP process is able to separate three representative polymers (polyethylene, ethylene vinyl alcohol, and polyethylene terephthalate) from a commercially available multilayer film with nearly 100% material efficiency, affording recyclable resins that are cost-competitive with the corresponding virgin materials.

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Here, we demonstrate a unique strategy we call solvent-targeted recovery and precipitation (STRAP) to deconstruct multilayer films into their constituent resins using a series of solvent washes that are guided by thermodynamic calculations of polymer solubility. Although relatively clean (as opposed to municipal wastes) and of near-constant composition, no commercially practiced technologies exist to fully deconstruct postindustrial multilayer film wastes into pure, recyclable polymers. Billions of pounds of these multilayer films are produced annually, but manufacturing inefficiencies result in large, corresponding postindustrial waste streams. Many plastic packaging materials manufactured today are composites made of distinct polymer layers (i.e., multilayer films).