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Efficient Synthesis of α,ω‐Divinyl‐Functionalized Polyolefins
Author(s) -
Patil Vishal B.,
Saliu Kuburat O.,
Jenkins Roxanne M.,
Carnahan Edmund M.,
Kramer Edward J.,
Fredrickson Glenn H.,
Bazan Guillermo C.
Publication year - 2014
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201400139
Subject(s) - degree of unsaturation , polyolefin , catalysis , polymer chemistry , chemistry , double bond , polymer , isomerization , metathesis , ethylene , gel permeation chromatography , ring opening metathesis polymerisation , grubbs' catalyst , organic chemistry , polymerization , layer (electronics)
A facile one‐step olefin metathesis‐mediated ethenolysis reaction on polyolefins containing 1,4‐inserted butadiene units yields α,ω‐divinyl telechelic polymers. These reactions can be successfully performed with well‐defined thermally stable ruthenium catalysts to yield essentially complete metathesis of internal double bonds. The reaction progress is monitored by 1 H NMR spectroscopy over time, by tracking the disappearance of the signal due to internal unsaturation of 1,4‐butadiene at ca. 5.5 ppm in toluene‐ d 8 solvent. The reaction conditions are optimized for ethylene pressure, temperature, catalyst loading, and reaction time. Catalyst loading of 45:1 1,4‐butadiene unsaturation to catalyst at 90 °C with 25 psi ethylene pressure is successful in removing internal unsaturation with no detectable isomerization side reactions. High‐temperature gel‐permeation chromatography (GPC) analysis of the depolymerized product correlates to the calculated molecular weight based on the number of internal double bonds observed in the 1 H NMR analysis of the starting polyolefin. This method offers a single step, rapid, and clean route toward divinyl‐terminated telechelic polymers based on commodity materials in high yields.