The Intrinsic Mechanochemical Reactivity of Vinyl-Addition Polynorbornene
Daniel C Lee1, Victoria K Kensy2, Christopher R Maroon3
1Molecular Engineering and Sciences, University of Washington, 3946 W Stevens Way NE, Seattle, WA, 98105, USA.
Abstract:
Herein we report the discovery of the intrinsic mechanochemical reactivity of vinyl-addition polynorbornene (VA-PNB), which has strained bicyclic ring repeat units along the polymer backbone. VA-PNBs with three different side chains were found to undergo ring-opening olefination upon sonication in dilute solutions. The sonicated polymers exhibited spectroscopic signatures consistent with conversion of the bicyclic norbornane repeat units into the ring-open isomer typical of polynorbornene made by ring-opening metathesis polymerization (ROMP-PNB). Thermal analysis and evaluation of chain-scission kinetics suggest that sonication of VA-PNB results in chain segments containing a statistical mixture of vinyl-added and ROMP-type repeat units.
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