Masters Theses

Abstract

"Modulated Differential Scanning Calorimetry (MDSC) was used to study the glass transition behavior of poly(methyl methacrylate) (PMMA) adsorbed onto silica substrates from toluene. Untreated fumed amorphous silica and silica treated with hexamethyldisilazane were used for the adsorption to probe the effect of polymer- substrate interactions. To test the effect of molecular weight on the Tg of adsorbed polymers, low polydispersity PMMA samples of varying molecular weights were used. The results revealed a broadening of the glass transition towards high temperatures. The observed increase in the glass transition breadth varied with adsorbed amount and the type of silica used for the adsorption. Larger increases in the glass transition temperature and breadth, as high as 60 °C, were observed for PMMA films on untreated silica. The larger increase in Tg was attributed to restricted segmental motions due to H-bonding between PMMA carbonyls and the surface hydroxyls.

The MDSC results were verified by Fourier Transform Infrared (FTIR) spectroscopy which showed a decrease in the bound fraction with increasing adsorbed amount for all the molecular weights studied"--Abstract, page iv.

Advisor(s)

Blum, Frank D.

Committee Member(s)

Stoffer, James O.
Rosen, Stephen L.

Department(s)

Chemistry

Degree Name

M.S. in Chemistry

Publisher

University of Missouri--Rolla

Publication Date

Spring 2002

Pagination

xi, 70 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2002 Moses Tlhabologo Kabomo, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Glass -- ResearchSurface chemistryPolymethylmethacrylate

Thesis Number

T 8066

Print OCLC #

50318288

Electronic OCLC #

1112359391

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