Highly branched polyethylene oligomers via group IV-catalysed polymerization in very nonpolar media

Yanshan Gao, Jiazhen Chen, Yang Wang, David B. Pickens, Alessandro Motta, Q. Jane Wang, Yip Wah Chung, Tracy L. Lohr, Tobin J. Marks

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11 Citations (Scopus)

Abstract

Early transition metal catalysts produce high-density and linear low-density polyethylenes with spectacular efficiency. Nevertheless, these catalysts are ineffective in producing low-density polyethylene homopolymers with large –(CH 2 ) x CH 3 branch densities (x ≥ 5) or low-molecular-mass (M n < 1,200 g mol −1 ) highly branched polyethylenes (HBPEs). The latter are potential alternative synthetic lubricants that have eluded efficient catalytic synthesis. Here we report the synthesis of low-M n HBPEs with 61–93 branches per 1,000 carbon atoms from abundant ethylene as the primary feedstock using a soluble, highly active ion-paired organozirconium catalyst in a saturated hydrocarbon solvent. The unprecedented activity and branch selectivity reflect previously unrecognized aspects of the cationic catalyst–counteranion pairing in nonpolar media and are characterized spectroscopically and quantum mechanically. The HBPE products are rheologically and tribologically attractive candidates for synthetic lubricants.

Original languageEnglish
Pages (from-to)236-242
Number of pages7
JournalNature Catalysis
Volume2
Issue number3
DOIs
Publication statusPublished - Mar 1 2019

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ASJC Scopus subject areas

  • Catalysis
  • Bioengineering
  • Biochemistry
  • Process Chemistry and Technology

Cite this

Gao, Y., Chen, J., Wang, Y., Pickens, D. B., Motta, A., Wang, Q. J., Chung, Y. W., Lohr, T. L., & Marks, T. J. (2019). Highly branched polyethylene oligomers via group IV-catalysed polymerization in very nonpolar media. Nature Catalysis, 2(3), 236-242. https://doi.org/10.1038/s41929-018-0224-0