ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Multiordering parameter models have been quite successful in rationalizing volume and enthalpy behavior of glasses subjected to various thermal histories in the glass transition range and even at lower temperatures. In the past we suggested a generalization of such models to encompass what is now termed physical aging, i.e., recovery as monitored by mechanical experiments such as creep and stress relaxation. Our initial investigation indicated qualitative agreement between the generalized model and experimental behavior. We have now more completely investigated this area and found a convenient approximation through which behavior can be calculated in most situations without using a distribution of mechanical relaxation or retardation times. Using this technique, we find that essentially quantitative agreement between this model and experimental results is possible only when a very sharp distribution of volumetric recovery times, like that of a single ordering parameter model, is used, Broader distribution functions result in aging behavior which is much more sluggish than observed experimentally. This result is particularly disturbing since such sharp distribution functions have been shown to be incompatible with direct observations of volume recovery.
Additional Material:
17 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760271703
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