Heterogeneous catalytic hydrogenaton of poly(vinylethylene).
01 January 1988
The hydrogenation of poly(vinylethylene) in cyclohexane ( 1% w/v) at 70C using a calcium-carbonate-supported palladium catalyst has been investigated. Evaluation of partially hydrogenated polymer by size exclusion chromatography and sup 1 H NMR spectroscopy reveals that this reaction initially proceeds by the concerted hydrogenation of approximately 85% of the unsaturated repeat units in individual polymer molecules during a single adsorption step from solution. This finding is qualitatively explained based on the unique adsorption characteristics of polymers, in conjunction with the estimated heats of adsorption for unsaturated and saturated hydrocarbons on group VIII metal surfaces.