Oxygen ageing effects

Heat ageing is not normally carried out in a vacuum or an inert atmosphere but in air or oxygen so that the ageing effect is caused by a combination of heat and oxygen. At high temperatures, the rate of oxidation of the rubber may be faster than the rate of oxygen diffusion so that uneven... 

Figure 1. Age effects on the rate of synthesis of export proteins (upper), the rate of oxygen consumption by isolated mitochondria (middle) and the total RNA content (lower) for the fat body of adult male B, discoidalis.

Sidorenko and Borshchevskiy (1977), who analyzed the general trend in the evolution of the isotopic composition of carbonates in the Precambrian and Phanerozoic, summarized all published data (up to 1976) and depicted them graphically (Fig. 25). In their opinion, the age effect in the oxygen isotopic composition is the result of regional metamorphism, as a global process. 

Figure 10. Aging effect of irradiated (2.5 Mrad) polypropylene in air at room conditions and in oxygen at 100°C as a function of % extension...

Co doped into single crystals of UO2 tends to show pronounced ageing effects including the appearance of a hyperline field. Reordering of interstitial oxygen around the ion [61], or precipitation of iron-rich phases [62] have been suggested as explanations. 

Kim, B. K. Kim, K S. Park, C. E. (2002). Improvement of wettabilitty and reduction of aging effect by plasma treatment of low-density polyethylene with argon and oxygen mixtures.. Adhes. Sci. Technol, Vol. 16, pp. 509-521, ISSN 0169-4243. 

Fig. 35. Oxygen permeability decay through BPA—BnzDCA films illustrating physical aging effects for the following film thicknesses o, 33 p,m , 28 p,m O, 9.7 / m A, 4.4 jiim V, 1.85 Atm . , 0.99 Atm , 0.74 Atm , 0.58 Atm A, 0.25 Atm. Reprinted from Ref 131 with permission from Elsevier..

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