Browsing by Author "Sutton, D"

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    Effects of selected process parameters on the morphology of poly(ethylene terephthalate) preforms and bottles
    (Wiley-Blackwell, 2007-10-05) Hanley, TL; Sutton, D; Karatchevtseva, I; Cookson, DJ; Burford, RP; Knott, RB
    Small-angle X-ray scattering (SAXS) studies and polarized optical microscopy were undertaken to explore possible morphological explanations for the poor mechanical strength in the petaloid bases of poly(ethylene terephthalate) bottles. With a standard commercial production line, one set of injection-molded preforms was over-packed by 1.1 wt % to investigate the effect on the molecular morphology with respect to a set of control samples. Both sets of preforms showed highly crystalline and oriented areas corresponding to the injection gate region. The main body of the control preform was amorphous, and although the overpacked preform was essentially amorphous, there was some evidence for weak crystallinity. The SAXS patterns of the bottle petaloid base blown from the corresponding preforms produced similar SAXS patterns for overpacked and control bottle bases, indicating that the commercial process is robust at least to this degree of overpacking. Optical microscopy showed detailed crystalline features around the gate region and thin crystalline layers sandwiched between a quenched skin layer in direct contact with the cold mold walls and the main flow of material into the mold. © 2007, Wiley-Blackwell.
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    Phase separation in the organic solid state: simultaneous synchrotron SAXS / DSC studies of unstable n-alkane blends
    (Australian Institute of Physics, 2005-01-31) Gilbert, EP; Nelson, A; Sutton, D; Terrill, N; Martin, C; Lal, J; Lang, EA
    Blends of normal alkanes form lamellar structures, when quenched from the melt, in which the separation of the individual chains may be controlled by the chain-length difference, molar composition, isotopic substitution and confinement. We have performed simultaneous synchrotron small-angle X-ray scattering and differential scanning calorimetry studies on 2:1 C28H58:C36D74 mixtures as a function of cooling protocol. Their simultaneous collection enables the temperature-dependent nanostructural changes to be correlated with phase transitions. The data are further complemented by small-angle neutron scattering highlighting the separation of the individual chains via isotopic contrast and optical microscopy indicating changes occurring on the macroscopic scale.