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Journal of Thermal Analysis and Calorimetry
Authors: M. Matthews, I. Atkinson, Lubaina Presswala, O. Najjar, Nadine Gerhardstein, R. Wei, Elizabeth Rye, and A. Riga

Abstract  

Dielectric analysis (DEA), supported by thermogravimetric analysis (TG), differential scanning calorimetry (DSC), powder X-ray diffraction analysis (PXRD) and photomicrography, reveal the chiral difference in the amino acids. The acids are classified as dielectric materials based on their structure, relating chirality to the vector sum of the average dipole moment, composed of the constant optical (electronic) and infra-red (atomic) polarizabilities, as well as dipole orientation. This study encompasses 14 L-and D-amino acid isomers. Physical properties recorded include AC electrical conductivity, charge transfer complexes, melting, recrystallization, amorphous and crystalline phases, and relaxation spectra, activation energies and polarization times for the electrical charging process.

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regarding the structure of the molecule and the process of dipole orientation. These studies also give an idea about inter- and intra-molecular forces. Further, they enable one to calculate thermodynamic parameters, such as change in activation energy for

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to calculate thermodynamic parameters such as change in activation energy for dipole orientation Δ G* , enthalpy Δ H* , entropy of activation Δ S* , and the other temperature dependent parameters such as relaxation time τ , the distribution parameter

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Abstract  

Functional parameters contributing to the recognizable good performance of a highly crosslinked olefinic polymer based on cyclopentadiene have been evaluated by a limited range of stress decay and creep recovery from a fixed deformation over constant time periods. The experimental design for these involved a calculated stress (load) at the initial sample deformation (displacement) for determination of changes in stress in bending mode and flex creep under applied load at three constant temperature segments of 6 h each with 20 min recovery time between segments. The results have identified a behavior which is typical of interfacial orientational effect in a two-component system. Thermal conductivity, heat capacity and density at the same temperatures were measured for determination of variations in thermal diffusivity as an indication of the competing effects of densification and thermal expansion for such a system. Static charging and polarization experiments were performed for evaluation of other desired uses of this material, in moving parts and in direct or induced voltage applications. The latter allows measurement of dynamic charge transport through the resin matrix. Calculations indicate generation of charge carriers from weak secondary bonding typical of polymer interlaces. The polarization itself consists of dipole orientation characterized by relatively high activation energy. The intrinsic mechanical properties for this material had been determined by the manufacturer, but the performance parameters reported in this study have been determined for the first time for exploration of further uses for this material.

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. The charges become polarized to compensate for the electric field such that the positive and negative charges move in opposite directions. At the microscopic level, several dielectric mechanisms can contribute to dielectric behavior. Dipole orientation

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Frohlich model itself. Considering the complex nature of the amorphous phase with multiple states of aggregation, any computational description of TSPC experiments would have to account for both a random distribution of dipole orientations as well as

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