• Cu(0)-RDRP of methacrylates in DMSO: importance of the initiator

      Jones, Glen R.; Whitfield, Richard; Anastasaki, Athina; Risangud, Nuttapol; Simula, Alexandre; Keddie, Daniel J.; Haddleton, David M.; University of Warwick; University of Warwick; University of Warwick; et al. (RSC Publishing, 2017-08-17)
      The controlled radical polymerization of methacrylates via Cu(0)-mediated RDRP is challenging in comparison to acrylates with most reports illustrating higher dispersities, lower monomer conversions and poorer end group fidelity relative to the acrylic analogues. Herein, we present the successful synthesis of poly(methyl methacrylate) (PMMA) in DMSO by judicious selection of optimal reaction conditions. The effect of the initiator, ligand and temperature on the rate and control of the polymerization is investigated and discussed. Under carefully optimized conditions enhanced control over the molecular weight distributions is obtained furnishing methacrylic polymers with dispersities as low as 1.10, even at very high conversions. A range of methacrylates were found to be tolerant to the optimized polymerization conditions including hydrophobic, hydrophilic and functional methacrylates including methyl and benzyl methacrylate, ethylene glycol methyl ether methacrylate and glycidyl methacrylate. The control retained during the polymerization is further highlighted by in situ chain extensions yielding well-defined block polymethacrylates.
    • Preparation of isomorphously substituted scandium ZSM-5 using aqueous fluoride gels.

      Brigden, Clive T.; Thompsett, David; Williams, Craig D. (RSC Publishing, 2004)
      Sc-ZSM-5 zeolite is synthesised using a hydrothermal fluoride based synthesis medium and evidence, viz. XRF, NMR, XRD, TGA and FT-IR shows that scandium (Sc3+) has been isomorphously substituted into the zeolite framework.
    • Synthesis and characterisation of aluminophosphate-based zeotype materials prepared with α,ω-bis(N-methylpyrrolidinium) alkane cations as structure directing agents.

      Maple, Martin J.; Williams, Craig D. (RSC Publishing, 2007)
      New routes to the preparation of two families of small pore microporous solids are described. Flexible diquaternary alkyl ammonium cations (C4H8)CH3N+(CH2)nN+CH3(C2H8), n = 3–5, have been found to act as structure directing agents in the synthesis of aluminophosphate-based materials of the ABC-6 group. The templates exhibit considerable selectivity in crystallising phases of the ERI or AFX-type (MeAPO-17 or MeAPO-56, respectively) from a wide variety of metalloaluminophosphate gels (Me = Mg2+, Co2+ or Si4+). For example, from gels containing Mg/P = 0–0.25, 1,4-bis(N-methylpyrrolidinium)butane cations gave MgAPO-17, and 1,5-bis(N-methylpyrrolidinium)pentane cations gave MgAPO-56. Notably, materials could be prepared with levels of metal-substitution tailored to a high degree and distributed non-randomly within the framework. As-prepared solids have been characterised by powder XRD, multinuclear solid state NMR, FT-IR, SEM, and thermal and elemental analysis.