Keywords and Phrases
Modulated differential scanning calorimetry (MDSC)
"Two components in the glass transition region of PMMA adsorbed on silica were observed using modulated differential scanning calorimetry (MDSC). One component was likely tightly bound to the substrate and the other component was more bulk-like in its thermal behavior. It was assumed that there was a limiting adsorbed amount, above which all polymer molecules would have more limited interaction with the silica. It was estimated that the silica would strongly interact with the polymer for a distance up to 0.91 run from the substrate surface. A model was developed from which the increment of heat capacity and glass-transition temperature (Tg) could be estimated for each component. Each sample was run in a MDSC using a ramp of 2.5 °C/min from ambient to 280 °C. The Tg for each component was determined from the MDSC thermogram. The Tg's for the first and second component were found to be 127 +/- 3 °C and 155 +/- 2 °C, respectively. It was found that these temperatures did not vary much with adsorbed amount. Based on a linear regression suggested from the model, the increment of heat capacity for the tightly-bound component was predicted to be approximately 0.2 the increment of heat capacity for the bulk polymer. A bound fraction of polymer was also calculated and compared with infrared measurements. The bound fraction, as a function of adsorbed amount, was similar to, but less than, that from infrared measurements"--Abstract, page iii.
Sitton, Oliver C., 1951-
Blum, Frank D.
Ludlow, Douglas K.
Chemical and Biochemical Engineering
M.S. in Chemical Engineering
University of Missouri--Rolla
ix, 95 pages
© 2004 Erin Nicole Young, All rights reserved.
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Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.http://merlin.lib.umsystem.edu/record=b5124269~S5
Young, Erin N., "Thermal characterization of the glass transition of adsorbed PMMA using modulated differential scanning calorimetry" (2004). Masters Theses. 2495.
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