Electronic Theses and Dissertations

Identifier

6626

Date

2020

Date of Award

8-7-2020

Document Type

Thesis

Degree Name

Master of Science

Major

Physics

Concentration

Materials Science

Committee Chair

Firouzeh Sabri

Committee Member

Muhammad Shah Jahan

Committee Member

Jon Moseley

Abstract

Many medical device applications have begun to incorporate an antioxidant, Vitamin E at low concentrations (0.1 – 0.3 Wt%) within Ultra-High Molecular Weight Polyethylene (UHMWPE) components of total joint replacement. The lowest detectable limit, currently, of vitamin-E within these UHMWPE components, is around 0.3 Wt%, while the most common concentration of vitamin-E in vitamin-E-blended UHMWPE components is 0.1 Wt%. With these components, therefore, science is currently limited to mostly observations of subsequent wear rates of the resulting UHMWPE product and assumptions regarding the effects of vitamin E. To fill this gap, this study has custom-blended a variety of UHMWPE with higher concentrations of vitamin-E (up to 15.0Wt%) to allow for the direct observation of vitamin E and its antioxidant role within UHMWPE. The samples were treated with ionizing radiation (the subjects of study) as is typically done in the manufacturing process and compared to non-irradiated controls, via Fourier Transform Infra-Red (FTIR) analysis and UV-Vis (Ultra-Violet-Visible spectrum) spectrophotometry, which no study has done before. While such higher concentrations of vitamin-E are not typically used in UHMWPE components of medical devices, they can allow better evaluation of vitamin-E directly, regarding its role in protection from oxidation and resulting degradation. Results suggest anti-oxidant effects at low concentrations of Vitamin-E as expected, but also possible “pro-oxidant” effects of Vitamin E at higher concentrations, and this study provides information which will help medical device manufacturers to improve the successful life of polyethylene components, as well as the community in general to understand the effects of vitamin-E in polyethylene.

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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