Synthesis and electrochemical modulation of the actuator properties of poly(phenazine-2,3-diimino (pyrrol-2-yl))

Magister Scientiae - MScThe focus of this study is to synthesize a novel hinged polymer actuator. The linking molecule (hinge) is phenazine with interconnected dipyrrole units.South Afric

Actuation behaviour of a derivatized pyrrole accordion type polymer

A monomer (Phenazine-2,3-diimino(pyrrole-2-yl)–PDP) derived from the condensation reaction between 2,3-diaminophenazine and a pyrrole derivative has been synthesized as a hinge molecule in the design of a zig-zag polymer. The monomer was polymerized both chemically and electrochemically in order to produce the polymer material, phenazine-2,3-diimino(pyrrole-2-yl (PPDP). During electrochemical polymerization the system was doped using 1,4-napthaquinone sulphonic acid (NQSA) and polyvinylsulfonic acid (PVSA) respectively, to improve conductivity. Characterization of the materials by Fourier transform infrared spectroscopy (FTIR) confirmed the successful linking of the starting materials to produce the hinge molecule and nuclear magnetic resonance spectroscopy (NMR) supported the FTIR data. The electrochemistry of the polymer in the doped and undoped state was evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)

Oxidative Stability of Middle Distillate Fuels. Part 1: Exploring the Soluble Macromolecular Oxidatively Reactive Species (SMORS) Mechanism with Jet Fuels

The soluble macromolecular oxidatively reactive species (SMORS) mechanism has recently been applied to jet fuel thermal oxidative degradation at high temperatures (250–550 °C). The primary purpose of this work is to further test the extant SMORS mechanism with carefully designed experiments at lower temperatures. First, synthetic SMORS precursors, 2-methylindole and 1,4-benzoquinone, were doped into a stable Jet A-1 in both mono- and oligomeric forms. Flask oxidative stress of these solutions at 90 °C for 60 min with an oxygen sparge significantly increases jet fuel thermal oxidative degradation. Second, a model compound experiment suggests SMORS precursors, phenol and 1,4-benzoquinone, are generated <i>in situ</i> from flask oxidation of a natural jet fuel component cumene (isopropylbezene) at 160 °C with an air sparge for 300 min. This observation is particularly significant for the thermal oxidative degradation of ultra-low sulfur diesel (ULSD) because it suggests that fuels with low heteroatom content may oxidatively degrade by the SMORS mechanism. Third, doping parts per million (ppm) levels of 2,4-dimethylpyrrole into oxidatively stable jet fuels followed by flask oxidation at 95 °C with an air sparge for 30 min results in significant oxidation of the jet fuels. This observation is particularly significant for the storage and thermal oxidative stability of Athabasca-tar-sands-derived middle distillates, which have previously been shown to contain alkylpyrroles; these middle distillates are predominate across the northern tier of the United States