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Chain transfer agents for the catalytic ring opening metathesis polymerization of norbornenes†‡ † This work is dedicated to the memory of Professor Robert H. Grubbs.‡ Electronic supplementary information (ESI) available. Seehttps://doi.org/10.1039/d2sc04078f

ABSTRACT: Here, we present a detailed study of the metathesis activity of conjugated 1,3 diene derivatives in ring opening metathesis polymerization (ROMP) using Grubbs' 3rd generation catalyst (G3). A comprehensive screening of those derivatives revealed that monosubstituted 1,3 dienes show similar reactivities towards G3-alkylidenes as norbornene derivatives. Therefore, they represent perfect candidates for chain transfer agents in a kinetically controlled catalytic ROMP. This unprecedented reactivity allowed us to catalytically synthesize mono-end-functional poly(norborneneimide)s on the gram scale. Much more complex architectures such as star-shaped polymers could also be synthesized catalytically for the very first time via ROMP. This inexpensive and greener route to produce telechelic ROMP polymers was further utilized to synthesize ROMP block copolymers using bifunctional ROMP and ATRP/NCL initiators. Finally, the regioselective reaction of G3 with 1,3 diene derivatives was also exploited in the synthesis of a ROMP-PEG diblock copolymer initiated from a PEG macroinitiator. Using a highly reactive chain transfer agent we show that norbornenes and its derivatives can be polymerized catalytically with ruthenium complex savings up to 300-times the amount required in a classical ROMP polymerization.

SUBMITTER: Mandal I

PROVIDER: S-EPMC9629056 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature

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