Rate of physical aging of polycarbonate at a constant tensile strain
| Autor: | Thor L. Smith, T. Ricco |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Physical aging
Materials science Polymers and Plastics Strain (chemistry) Tension (physics) Tensile strain Dynamic mechanical analysis Condensed Matter Physics visual_art Materials Chemistry Stress relaxation visual_art.visual_art_medium Physical and Theoretical Chemistry Composite material Polycarbonate Constant (mathematics) |
| Zdroj: | Journal of Polymer Science Part B: Polymer Physics. 28:513-520 |
| ISSN: | 1099-0488 0887-6266 |
| DOI: | 10.1002/polb.1990.090280406 |
| Popis: | A study was made of the physical aging of an annealed polycarbonate film at a constant extension of 2.6% at 5 temperatures from 30 to 110°C. During stress relaxation at the constant extension, the storage modulus in tension, E′, was determined by imposing a sinusoidal strain of small amplitude at frequencies up to 25 Hz during an aging period, commonly of 5 h. Plots of log E′ against log f, where f is the frequency, gave parallel straight lines, each at a different aging (elapsed) time te. These lines were superposed by shifts along the abscissa. The obtained shift factors log a varied linearly with log te, the slope being the aging rate μ, a quantity introduced by Struik. The results show that μ is about 1.37 at 30°C and that it increases progressively with the temperature and becomes approximately 2.13 at 110°C. Another measure of the aging rate is the rate of increase of E′ with te, expressed as the percent increase per decade of the aging time. This quantity also increases progressively with the temperature from about 2.6% at 30°C to nearly 3.5% per decade of time at 110°C. |
| Databáze: | OpenAIRE |
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