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Phenyl-Terminated Polyolefins via Living Coordinative Chain Transfer Polymerization with ZnPh2 as a Chain Transfer Agent

Published

Author(s)

Mark Wallace, Aaron Burkey, Lawrence Sita

Abstract

ABSTRACT: Living coordinative chain transfer polymeriza-tion (LCCTP) of α-olefins, including propene, 1-hexene, 1-decene, and 4-methyl-1-pentene, using the CPAM Hf pre-in-itiator 1, the borate co-initiator B1, and excess equivalents of diphenylzinc (ZnPh2) as chain transfer agent, provides excellent yields of the corresponding phenyl-terminated polyolefins with tunable degree of polymerization (DPn) and very symmetric and narrow molecular weight distribu-tion (e.g. Ð ≤ 1.1). Reactive quenching of ZnPh2-mediated LCCTP with molecular iodine (I2) further provides the or-thogonally difunctionalized α-iodo, ω-phenyl polyolefins (x-PAO-Ph). Use of diethylzinc (ZnEt2) in place of ZnPh2 under otherwise identical conditions provides the corresponding ethyl-terminated polyolefin products (x-PAO-Et) with nearly the same DPn and Ð values. A mechanism is proposed for R' group transfer from ZnR'2 and polymeryl (P) group transfer from ZnP2 during LCCTP that involves nucleophilic attack on a coordinated olefin and avoids formation of a Hf-R' bonded intermediate. These results serve to advance LCCTP further for the production of next generation poly-olefins.
Citation
ACS Catalysis

Keywords

living, chain transfer, polymerization, poly-olefin

Citation

Wallace, M. , Burkey, A. and Sita, L. (2021), Phenyl-Terminated Polyolefins via Living Coordinative Chain Transfer Polymerization with ZnPh2 as a Chain Transfer Agent, ACS Catalysis, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932342 (Accessed March 2, 2024)
Created October 25, 2021, Updated November 29, 2022