Browsing by Author "Rudham, Robert"

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    Dehydration of Propan-2-ol on X Zeolites
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (09), 1974) Gentry, Stephen J.; Rudham, Robert
    The dehydration of propan-2-ol on moderately protonated X zeolites leads to the formation of both propene and di-isopropyl ether at temperatures in the range 383-430 K. Unexchanged zeolite was considerably less active, and only yielded propene at temperatures in the range 444-450 K. With protonated X zeolites the rates of formation of both products were investigated as a function of temperature, pressure of propan-2-ol and the extent of protonation, which lay between 8.6 and 28.4 %. Decomposition at 411 K. was completely poisoned by pyridine vapour. The Bronsted acidity of the accessible hydroxyl groups within the zeolites is considered to be the source of activity, and a mechanism involving carbonium and oxonium ions is proposed.
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    Kinetic Studies of Olefin Polymerization on a Supported Ziegler Catalyst
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (11), 1977) Eley, Daniel D; Keir, Douglas A; Rudham, Robert
    Microgravimetric measurements have been used to follow the polymerization of ethylene and propylene on a supported Ziegler catalyst prepared by treatment of MgO with TlCl4 followed by AlEt3. Polymerization between 273 and 320 K obeyed the parabolic law, with activation energies close to those for monomer permeation through the corresponding polymer. These observations, together with a first order dependence on monomer pressure, were taken to indicate that monomer permeation through an encapsulating polymer film was the rate determining step. Quantitative considerations suggest that the encapsulated material consists of agglomerates of MgO crystallites, such that the effective catalyst area is two orders of magnitude less than the B.E.T. area of the MgO.