Dielectric Measurement and Analysis of Ultrastable PMMA Glass
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Date
2022-02-09
Authors
Cai, Zhaohui
Journal Title
Journal ISSN
Volume Title
Publisher
University of Waterloo
Abstract
A stable glass, distinguished from an ordinary glass, has phenomenal characteristics such
as a high density and a high kinetic stability. In this project, stable glasses of poly(methyl methacrylate) (PMMA) are produced by physical vapor deposition (PVD), and the dielectric responses of the vapor-deposited PMMA glasses are measured at 1 kHz with a high precision capacitance bridge. Measurements of the dielectric loss and storage have been done by heating and cooling the vapor-deposited PMMA glasses, where the heating and cooling cycles are used to rejuvenate the vapor-deposited PMMA glasses and to directly compare stable and nominally rejuvenated glasses. A noticeable suppression in β relaxation peak could be observed in the dielectric loss curve for vapor-deposited glasses (stable glasses) as compared to that for rejuvenated glasses (ordinary glasses). This finding implies that the glass stability essentially influences the dielectric relaxation.