Doctoral Dissertations

Shu Hua Wu

Abstract

"Various chemical and physical aspects of high lipid absorption by medical grade silicone rubber and the dynamic mechanical properties of lipid-rubber systems were studied in order to provide an insight into the problem of 'variance' of these materials when subjected to 'in vitro' and 'in vivo' environments. Wide variations of post cure procedures of the silicone rubber were studied. Different post cures did not appreciably affect the mechanical properties of the silicone rubber. Mass transfer studies demonstrated that the diffusion of linolenic acid into a silicone rubber slab is a purely physical diffusion process (D = 3.2 x 10-3 cm2/min). Pure diffusion did not account for the high lipid uptake of silicone rubbers which had been exposed to a human environment. Several 'in vitro' tests utilizing a metal salt (FeCl3) as a catalyst inside the silicone rubber produced a 21% lipid weight gain in 10 days.

A possible mechanism for high lipid uptake of the silicone rubber is proposed. The mechanism is consistent with reported analytical findings of 'in vivo' lipid tests. Dynamic mechanical (viscoelastic) property studies indicated that silicone rubbers which had high lipid uptakes were deteriorated. At body temperature the modulus of the lipid-rubber system (35% lipid uptake) was 0.34 x 108 dyne/cm2 compared to 1.0 x 108 dyne/cm2 for new silicone rubber.

The findings of this investigation will serve as a foundation for further study directed toward the elimination of high lipid uptake when silicone rubber is subjected to 'in vivo' environments "--Abstract, page iii.

Advisor(s)

Mayhan, Kenneth G.

Committee Member(s)

Koorajian, Samuel
Bertrand, Gary L.
Wellek, Robert M.
Park, Efton
Venable, Raymond L., 1935-2008
Patterson, G. K. (Gary Kent), 1939-

Department(s)

Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering

Sponsor(s)

University of Missouri--Rolla. Graduate Center for Materials Research
University of Missouri--Rolla. Department of Chemical Engineering
National Institutes of Health (U.S.)

Publisher

University of Missouri--Rolla

Publication Date

1974

Pagination

xi, 130 pages

Note about bibliography

Includes bibliographical references (pages 127-130).

Rights

© 1974 Shu Hua Wu, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

Silicone rubber -- AnalysisLipidsViscoelasticity -- Mathematical models

Thesis Number

T 3038

Print OCLC #

6013276

Electronic OCLC #

914353992

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