Thesis (Ph.D.)--McMaster University, 2004. / Advisor: Shiping Zhu. Also available via World Wide Web.

A mathematical model was derived for the oxidation behaviour of a polymer film, taking into account both diffusion free and diffusion controlled kinetics. Comparison with experimental results showed excellent agreement. Expressions were derived from this model for the reaction induction time, and the limiting thickness of film at which diffusion effects become important. Investigation of the photostabilisation mechanism of Hindered Amine Light Stabilisers was undertaken. After experimental investigation of numerous proposed stabilisation processes, and their rejection, a reaction scheme was proposed involving the scavenging of trace transition metal ions in the polymer matrix.

Ph.D. (Chemistry) / Please refer to full text to view abstract

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Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Andrew Hrymak. Includes bibliographical references (leaves 157-168). Also available online.

Lower critical solubility temperatures (LCST) have been measured for polyethylene (PE), polypropylene, ethylene-propylene copolymers, polybutene-1, polypentene-1 and poly 4-methylpentene-1 (P4MP1) in twenty-five isomeric alkanes. The LCST for PE are much lower than for branched polyolefins, especially in branched alkanes. The results are not predicted by the Prigogine-Flory-Patterson theory but are understood in terms of correlations of molecular orientations in the PE melt. / Fusion thermodynamics of P4MP1 confirm the existence of ordered conformations in the melt. The thermoreversible gelation of P4MP1 solutions depends on solvent and thermal history. It is studied by calorimetry, viscosimetry and wide angle X-ray diffraction. The gel crosslinks are presumably of a fringed-micellar nature and their formation is tentatively associated with the existence of helical conformations of P4MP1 in solution. The latter is also responsible for the obtaining of four different crystalline structures of P4MP1 from solutions and gels. Preliminary measurements of dynamic mechanical properties of P4MP1 gels are reported.

Thesis (Ph.D.)--Case Western Reserve University, 2009 / Abstract Department of Macromolecular Science and Engineering Title from PDF (viewed on 16 April 2009) Available online via the OhioLINK ETD Center

Thesis (Ph. D.)--University of Massachusetts Amherst, 2009. / Includes bibliographical references (p. 98-107). Print copy also available.

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