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The ring-opening polymerization of 3-methyl-1,4-dioxan-2-one (MDO) mediated by a catalytic system composed of Y[N(TMS)2]3 and benzyl alcohol (BnOH) led to a new polymer (PMDO) comprised of perfectly alternating lactic acid and ethylene oxide repeat units. Samples of PMDO were characterized by NMR spectroscopy, size exclusion chromatography (SEC), and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). In a series of MDO polymerizations ([MDO]0 ) 3.0 M in toluene, between -30 and 60°C), the equilibrium monomer concentrations were measured. The thermodynamic parameters for the polymerization reaction were determined: ∆Hp°) -12.1 ( 0.5 kJ mol -1 and ∆Sp°) -42 ( 2 J mol -1 K -1 . The glass transition temperature (Tg) of PMDO was determined to be ≈-24°C by differential scanning calorimetry and found to vary little over the molecular weight range studied (3-21 kg/mol). Mixtures of low-molecular-weight PMDO and atactic polylactide (PLA) were prepared by solution casting and subsequent annealing significantly above the Tg's of the individual components. Miscibility of PLA and PMDO was evinced by single Tg's that were well-described by the Fox relationship for miscible blends. Because of its miscibility with PLA and low Tg, PMDO has potential as a macromolecular plasticizing agent for commercially relevant PLA.

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Porous SnO 2 /multiwalled carbon nanotube (CNT) thin film composites as anode material for Li-ion batteries were prepared using the electrostatic spray deposition (ESD) technique. The morphologies of the samples were found to be affected mainly by deposition temperatures. Electrochemical test cells were assembled using the as-prepared samples without any conductive additive or binder. The influence of deposition temperature and CNT content on the electrochemical performance of the anodes was investigated. Compared to pure tin oxide and pure CNT, the composite anode materials showed better discharge capacity and cyclability. Among the composites, the sample deposited at 250 C with 30 wt% CNT content was found to show better energy capacity. This can be ascribed to the porous nature of the anodes and the improvement in the conductivity by the addition of CNTs.

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