Document Type

Thesis

Date of Award

Spring 5-31-2003

Degree Name

Master of Science in Materials Science and Engineering - (M.S.)

Department

Committee for the Interdisciplinary Program in Materials Science and Engineering

First Advisor

Michael Jaffe

Second Advisor

Jing Wu

Third Advisor

Roumiana S. Petrova

Fourth Advisor

Treena Livingston Arinzeh

Abstract

Polymeric biomaterials are artificially synthesized polymers designed for in-vivo use. The material must be characterized and should satisfy the requirements suitable in human bodies.

For the proper characterization of materials, it is essential to apply specific processes, analyze thermal and mechanical properties, and understand the process effect and the morphology. Thermal analysis is one of the most sophisticated and well developed techniques for polymer characterization. Turi [ 1 ] has explained about the thermal characterization of polymeric materials. Jaffe et al [2], in the chapters of characterization of fibers and films, emphasized the effect of the process history of a polymer to the end-use by thermal analysis.

The polymer used for this study is a Kohn polymer which is a bioerodible, desaminotyrosyl-based polyarylate combinatorial library synthesized by Kohn and coworkers [3-5]. The polymer has two substitutable sites in the main chain and the branch.

The kohn polymer library is established by the change of the number of methylene groups in the two sites. Accordingly, various Kohn polymers can be produced, and several polymers were selected from the library and spun to fiber forms as a use of bioerodible scaffolds for anterior cruxes ligament repair [6]. In this study, the focus is on the poly (DT 12, 10). It was selected because of the stability of its orientation [6, 7]. The abbreviation, DT, represents Desamino Tyrosil, and the numbers indicate number of methylene groups in the side chain and the main chain respectively.

Spinning, drawing, and annealing processes were applied to the fiber, and then analyzed by Thermomechanical Analysis (TMA) Differential Scanning Calorimetry (DSC) for figuring out the influence of processes on the properties. Polarized Light Microscopy (PLM) and X-ray diffraction were used to determine the structure. As a result, it was found that all the processes developed the properties effectively. One of the major findings was that the polyarylate fiber exhibited a highly negative coefficient of thermal expansion, and the optical micrograph, which showed a liquid crystal pattern, confirmed that the poly (DT 12, 10) possesses a layered liquid crystal structure regarded as a smectic phase.

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