Rubber structural changes in thermal aging process there? Rubber structural changes in thermal aging process can be divided into two categories: one is the molecular chain degradation based thermal aging reaction (pyrolysis technology); crosslinked molecular chains between two categories is based hot oxygen Aging (structured). Natural rubber containing isoprene rubber, butyl rubber, ethylene propylene rubber, homo type epichlorohydrin rubber and polyvinyl alcohol co-rubber. Such rubber in appearance occurred after thermal aging performance of soft, sticky. Butadiene rubber containing butadiene rubber thermal aging process, occurring mainly the crosslinking reaction, similar to a rubber varieties as well as NBR / SBR / CR / ERDM / FPM / CSM and the like. Such rubber in appearance occurred after thermal aging performance of hard and brittle. Rubber aging protection methods are there? Due to the aging of rubber is a complex integrated chemical reaction process, but also to prevent aging of rubber is absolutely impossible, may take appropriate measures to slow the rate of aging of rubber, rubber to achieve extended service life. Aging measures are physical protection and chemical protection law. Physical protection method refers to avoid aging factors interact with a variety of rubber, such as the use of the surface layer or treated with light shielding agent, plus paraffin. Chemical protection method refers to the addition of certain substances to prevent or delay the rubber aging proceed, such as adding an amine or a phenolic antioxidant chemical. Antioxidant and with what effect? In order to improve the protective effect, in the actual application is often the choice of two or more kinds of antioxidants have different mechanisms of action carried out with, or use the same mechanism of antioxidant protection and use, or use on the same molecular mechanisms acting in different groups antioxidant group exist, and there are three with After Effects, as follows: 1, against the effect refers to two or more of the antioxidant used, the effect produced by the effect of them is less than when used alone and. Research shows that when acidic alkaline antioxidant with significant antioxidant used, since both will have a similar salt compound, resulting confrontation effect. Carbon black in the rubber in both the inhibition of oxidation and facilitate oxidation, in the presence of chain scission type antioxidant, decreases the inhibitory effect of the carbon black, or carbon black in the presence of antioxidant protection performance degradation, are clearly indicating an effect confrontation between them. 2, plus Wo effect is antioxidant and protective effect produced by equal after they each use a small sum. In the choice of antioxidant used, can produce effects when applied Wo basic requirement. After using the same type of antioxidant and generally produce only plus bluegrass effect, but sometimes After you get other benefits. For example, two volatile phenolic antioxidant and with different, not only can produce plus bluegrass effect, and compared with an equal amount of antioxidant used alone to play in a wider temperature range inhibitory potency. 3, synergistic effect is antioxidant used after each antioxidant effect is greater than the effect of single-use and.