Zhengzhou Rainbow Rubber Products Factory Contact: Fengjing Li phone: 15038139303 13613852984 QQ: 284163392 Address: Zhengzhou Zhongyuan District Xisanhuan Ping Wancun six groups http://www.zzhhxjzp.com/ rubber protective ozone aging and ozone is an important factor leading to the aging of the rubber occurs in the atmosphere. Ozone is more reactive than oxygen, so it is much more serious invasion of rubber, especially unsaturated rubber than oxygen. After the atmospheric ozone (o3) is the absorption of shortwave ultraviolet sunlight by oxygen molecules, the decomposition of oxygen atoms recombine with oxygen molecules formed. Away from the Earth's surface 20? 30km presence of Gao air concentration of approximately 5X10- ozone layer 'with the vertical flow of air, ozone was brought to the earth's surface, the ozone concentration decreased to the ground from a height. In addition, ultraviolet light concentrated in places, nearby places and motor discharge, especially where spark will produce ozone. Usually atmospheric ozone concentration is 0? 5X10-8. Different regions' different concentrations of ozone; different seasons, different concentrations of ozone. Although low concentrations of ozone near the ground, but the damage was caused by the rubber can not be ignored. Unsaturated rubber prone Exterior features ozonation and ozonation after thermal aging and different, one rubber ozonation only in the surface layer of ozone in contact with, the entire process is the outside to the inside of ozone process; the second is the reaction of the ozone layer of rubber and silver dura (about lOnm thick), under static conditions this film can prevent ozone deep contact with the rubber, but under conditions of dynamic strain or tension in a static state when the rubber After elongation or tensile stress when it exceeds the critical elongation or critical stress, this layer of film can lead to cracking and ozone to the new rubber surface contact, continued ozone reaction and crack growth, in addition to cracks Because the base of a stress concentration, it is easier to deepen the rift and thus the formation of cracks. Direction perpendicular to the direction of stress cracks, usually in small strains (eg 5%) and only a small number of cracks, crack direction legible, when the rubber multi-directional force is difficult to distinguish the crack direction. A rubber ozonation reaction mechanism of ozone with the reaction mechanism of an unsaturated rubber, can be described with reference to the following formula. When ozone exposure rubber products, ozone and lively first double bond addition reaction of molecular ozonide ①, ozonide very unstable molecule, quickly decomposes carbonyl compounds and zwitterionic ② ③. In most cases zwitterionic and carbonyls will recombine into stench oxide?, Zwitterionic peroxide can be polymerized to form two? Peroxides or high?, While when the presence of an inert solvent such as methanol, zwitterionic also reaction with methoxy hydroperoxide ⑦. The reaction of ozone with unsaturated rubber activation energy is very low, the reaction easily, and the reaction until the completion of the double bond of the rubber consumed, at which point the loss of elasticity of the film to form a layer of silver on the surface of the rubber, as long as no external force film turtle crack, rubber will no longer continue to ozonation. Should already ozonated rubber to produce dynamic deformation or stretching, the film produced will ozonated cracked, exposing new rubber surface will react with the ozone generator, which makes cracks continue to grow. Saturated rubbers because no double bonds, although the reaction with ozone, but can also occur reaction slowly, not easy to produce cracking. There were many people on the unsaturated rubber ozone generation and growth of cracks done research. These researchers based on their experimental data are proposed mechanism of crack generation and growth. For example, some believe that the generation of cracks, due to breakage of the molecular chain is under stress due to the decomposition of the ozonide, the result tends to separate from each other is greater than the tendency of recombination. The crack growth in the ozone concentration and rubber molecular chain mobility related to a certain time when the ozone concentration, the greater the molecular chain movement, the faster crack growth. Some people think that the physical properties of ozone generation and growth of cracks to form ozone and rubber ozonide thin rubber physical properties as well as with the original surface layer related to the different. For example, Murray considered rubber ozonation process is a process of physical and chemical processes occur together. When the rubber in contact with ozone, the surface of the double bonds react quickly with ozone, mostly generated ozonide, so that the original supple rubber chains rapidly converted to contain a lot of stiff chain ozonide ring. When a stress is applied to the rubber, the tensile stress in the rubber chains started to make more double bonds with ozone exposure, the rubber chains contain more ozonide ring and become more brittle. Embrittlement of the surface under stress or dynamic stress is very prone to cracking.