Rubber Granule Aging Factors
A) Oxygen: Oxygen occurs in the rubber with a free-radical chain reaction with the rubber molecules, the molecular chains are broken or cross-linked, causing changes in rubber properties. Oxidation is one of the important reasons for rubber aging.
B) Ozone: Oxygen is a much more reactive and destructive chemical oxygen species that destroys molecular chains. However, the effect of ozone on rubber varies depending on whether rubber is deformed or not. When acting on the deformed rubber (mainly unsaturated rubber), a crack that is in a direction perpendicular to the direction of the stress occurs, that is, the so-called "ozone crack". When acting on the deformed rubber, only an oxide film is formed on the surface without cracking.
C) Heat: Raising the temperature can cause thermal cracking or thermal crosslinking of the rubber. But the basic role of heat or activation. Improve the rate of oxygen diffusion and activation of oxidation reactions, thereby accelerating the rate of rubber oxidation reaction, which is a common phenomenon of aging
D) Light: The shorter the light, the greater the energy. Destructive effect on the rubber is the higher energy UV. In addition to ultraviolet light can directly cause the fracture of the rubber molecular chain and crosslinking, the rubber due to the absorption of light energy and generate free radicals, trigger and accelerate the oxidation chain reaction process. The outside light plays a role in heating. Light Another feature of its director (with different heat) is that it is mainly in the rubber surface into the students. High gel content of the sample, there will be mesh cracks on both sides, the so-called "light outer split
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