ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Thermoelectrets of poly(methyl methacrylate) were exposed to various atmospheres of known relative humidity between 0 and 100% and the thermal current spectra analyzed. The study of the decrease of the heterocharges as a function of the exposure time reveals important differences in stability between the three peaks of the spectrum; the two peaks appearing at low temperatures can be attributed to a uniform volume polarization, and the third peak observed at high temperature to a space charge polarization. The shift of the peaks indicates plasticization of the polymer by water vapor. This effect is reversible when the samples are exposed for a sufficiently long time to a drying atmosphere. The complex variations of the initial rise of the spectrum as a function of the exposure time show that the activation energy of the peaks probably depends upon the degree of hydration of the polymer.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1974.180120510
