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|Title:||Morphology and Properties of Amorphous Polyethylene Terephthalate|
|Department / Program:||Metallurgy and Mining Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Physical and mechanical properties of amorphous polyethylene terephthalate (PET) have been measured. A uniform morphology was observed when PET thin film (ca. 1000 (ANGSTROM)) was ultraquenched from above its equilibrium melting temperature. Sufficiently rapid quenching rate below T(,g) and heating above the critical temperature before quenching were identified as necessary conditions to produce uniform morphology. Under other conditions, a conventional nodular morphology was observed.
From physical and mechanical properties of ultraquenched and ice water quenched thicker films (ca. 10 (mu) to 150 (mu)) it is inferred that the nodules observed in thin film possess at least orientational order. Short range coplanarity of the benzene rings, formed by a nucleation-and-growth mechanism, is tentatively assigned to be such orientational order. The quenching and room temperature aging results can also be explained in terms of spinodal decomposition, a process very closely related to dissipative structure formation under conditions far from equilibrium. However, the annealing (at 55(DEGREES)C, 20(DEGREES)C below T(,g)) results are not compatible with the linear theory of the early stage of decomposition.
During the course of this study new methods of preparing thin films were developed to be used in torsion pendulum measurements. Automation of the torsion pendulum was also partially completed.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.
|Date Available in IDEALS:||2014-12-16|
This item appears in the following Collection(s)
Dissertations and Theses - Metallurgy and Mining Engineering
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois