A critical assessment of the Arrhenius oven-aging methodology
The Arrhenius approach assumes a linear relation between log time to material property change and inverse absolute temperature. For elastomers, ultimate tensile elongation results are often used to confirm Arrhenius behavior, even though the ultimate tensile strength is non-Arrhenius. This paper critically examines the Arrhenius approach. Elongation vs air-oven aging temperature for a nitrile rubber, gives an E[sub a] of 22 kcal/mol; however this does not hold for the tensile strength, indicating degradation. Modulus profiling shows heterogeneity at the earliest times at 125 C, caused by diffusion-limited oxidation (DLO). Tensile strength depends on the force at break integrated over the cross section, and nitrile rubbers aged at different temperatures experience different degrees of degradation in the interior. Modulus at the surface, however, is not affected by DLO anomalies. Severe mechanical degradation will occur when the edge modulus increases by an order of magnitude. 7 figs, 3 refs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6567936
- Report Number(s):
- SAND-93-0600C; CONF-9304103--1; ON: DE93011573
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360603* -- Materials-- Properties
ACTIVATION ENERGY
AGING
ARRHENIUS EQUATION
CHEMICAL REACTIONS
ELASTOMERS
ELONGATION
ENERGY
EQUATIONS
MECHANICAL PROPERTIES
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
OXIDATION
POLYMERS
RUBBERS
SURFACES
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TENSILE PROPERTIES