Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. Includes bibliographical references (leaves 231-236).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 348-356).

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1986. / Vita. Abstract. Includes bibliographical references (leaves 232-239). Also available via the Internet.

No description available.

The work described in this thesis aims at a better understanding of several ionomers and their blends on a microscopic level especially poly (butylene terephthalate) (PBT) and sulphonated poly (butylene terephthalate) (SPBT). The commercial importance of ionomer blends stems from the fact that the inclusion of sulphonate groups can improve or enhance the optical clarity of a blend made with non-sulphonated material. In particular, the present work investigates the optimum blend composition and level of sulphonation for a partially miscible sulphonated poly (butylene terephthalate) and polycarbonate (SPBT/PC) blend system. It has been found that the most transparent blends were SPBT/PC 7.9 mole % sulphonation 25/75 and 11.1 mole % sulphonation 50/50. The principal part of this thesis deals with characterisation of polymer blends using primarily differential scanning calorimetery (DSC) and thermogravimetry analysis (TGA). The second part of the thesis contains an investigation of the structural and microstructural properties of the functionalized PBT both in the homopolymer and in a blend with PC, and polystyrene ionomers by wide angle X-ray diffraction, (WAXD) and light microscopy. For comparison, a series of polystyrene ionomers were studied. The similar behaviour of PS ionomers (which are model random ionomers) to that of PBT ionomers gives an additional support to this study. It follows from the above studies that upon increase of the level of sulphonation a change in the structural properties of the material results in a reduced crystallinity of PBT. This leads to increased miscibility of the PBT/PC blend.

This thesis describes an investigation of the structure and viscoelastic properties of telechelic polymers as well as the dynamic and dielectric properties of ethyl acrylate-based ionomers, a material of medium dielectric constant. / Stress relaxation studies of low molecular weight sodium carboxylate-terminated polystyrene and polybutadiene will show that time-temperature superposition does not hold for samples with greater than 6 mole % ion content. It is shown that two mechanisms are operative, the first proceeding with an activation energy of circa 600 kJ/mole and the second proceeding with an activation energy of circa 142 kJ/mole at T(,g) and at a rate of 2.9 x 10('-6) sec('-1). / The dynamic mechanical and dielectric properties of a series of ethyl acrylate-based ionomers are described in the second part of this thesis. The results are consistent with the hypothesis that below 12 mole % the ions form simple multiplets which act as transient cross-links, while above that concentration cluster formation is encountered.

No description available.

No description available.

The structure-property relationships of sulfonated polysulfone ionomers were investigated. The techniques of Fourier Transform Infrared, Differential Scanning Calorimetry, Dynamic-Mechanical Analysis, Small Angle X-ray Scattering and Water Absorption were used to provide Information on the nature of ionic interactions 1n these Ionomers. From these structure-property studies, the ionomeric structure is best described as consisting largely of ionic multiplets composed of ion pairs, quartets, etc.