Dihydroxy Polyethylene Additives for Compatibilization and Mechanical Recycling of Polyethylene Terephthalate/Polyethylene Mixed Plastic Waste

Aristotle J Zervoudakis, Caitlin S. Sample, Xiayu Peng, Davis Lake, Marc A. Hillmyer, Christopher J. Ellison

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

Polymer blend compatibilization is an attractive solution for mechanical recycling of mixed plastic waste because it can result in tough blends. In this work, hydroxy-telechelic polyethylene (HOPEOH) reactive additives were used to compatibilize blends of polyethylene terephthalate (PET) and linear low-density polyethylene (LLDPE). HOPEOH additives were synthesized with molar masses of 1-20 kg/mol by ring-opening metathesis polymerization of cyclooctene followed by catalytic hydrogenation. Melt-compounded blends containing 0.5 wt % HOPEOH displayed reduced dispersed phase LLDPE particle sizes with ductilities comparable to virgin PET and almost seven times greater than neat blends, regardless of additive molar mass. In contrast, analogous blends containing monohydroxy PE additives of comparable molar masses did not result in compatibilization even at 2 wt % loading. The results strongly suggest that both hydroxy ends of HOPEOH undergo transesterification reactions during melt mixing with PET to form predominantly PET-PE-PET triblock copolymers at the interface of the dispersed and matrix phases. We hypothesize that the triblock copolymer compatibilizers localized at the interface form trapped entanglements of the PE midblocks with nearby LLDPE homopolymer chains by a hook-and-clasp mechanism. Finally, HOPEOH compounds were able to efficiently compatibilize blends derived solely from postconsumer PET and PE bottles and film, suggesting their industrial applicability.

Original languageEnglish (US)
Pages (from-to)1396-1402
Number of pages7
JournalACS Macro Letters
Volume11
Issue number12
DOIs
StatePublished - Dec 20 2022

Bibliographical note

Funding Information:
The authors would like to thank Prof. Kailong Jin and Dr. Charles McCutcheon for synthesis of the monohydroxy PE additives. The authors also thank Prof. Frank S. Bates for helpful discussions and for conception of the “hook and clasp” mechanism name. The authors acknowledge our principal funding source, the National Science Foundation Center for Sustainable Polymers at the University of Minnesota, which is a National Science Foundation supported Center for Chemical Innovation (CHE-1901635). Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from the NSF through the MRSEC (Award Number DMR-2011401) and the NNCI (Award Number ECCS-2025124) programs.

Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.

MRSEC Support

  • Shared

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

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