Multicomponent plastics, such as those used in food packaging, are ubiquitous in everyday life. However, they are inherently difficult to recycle because the components are usually immiscible. Since direct melt processing of mixed stream plastics results in macrophase separated blends with poor mechanical properties, presorting is almost always required for their recycling. In this work, we propose an alternative approach of recycling polyester and polyolefin blends using poly(ethylene terephthalate)-poly(ethylene) multiblock copolymers (PET-PE MBCP) as compatibilizers. Using atomic force microscopy, scanning electron microscopy, and uniaxial tensile testing, we demonstrated that adding 2 wt% of PET-PE MBCP in 80/20 wt% PET/PE blends caused a 10-fold decrease in the PE droplet size that was stable to further static annealing. The MBCP improved PET/PE interfacial adhesion by over two orders of magnitude, and this aided in stress transfer to produce tough blends. These results indicate MBCPs can efficiently work as compatibilizers to facilitate the recycling of multicomponent plastic waste by simple melt reprocessing.

Multiblock copolymers for compatibilizing and recycling polyesters and polyolefins

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.