Droplet‐in‐Droplet Polymer Blend Microstructures: a Potential Route Toward the Recycling of Co‐mingled Plastics

Abstract The problem of recycling co‐mingled plastics is primarily related to the problem of multiple interfaces in multicomponent immiscible polymer blends. Here, we study a new concept where thermodynamically driven polymer segregation and phase encapsulation are used to locate multiple phases within one of two major phases. Starting from a co‐continuous blend of HDPE and PP, hierarchically encapsulated PS/PMMA/PC composite droplets are found to be exclusively located within PP when the principal HDPE/PP interface is compatibilized. The mechanical properties of the structures demonstrate an improved tensile strength and modulus as well as ductility under the appropriate processing conditions. This approach has potential as a novel route toward the recycling of co‐mingled plastics.