Rubber fatigue aging refers to the phenomenon that the rubber macromolecules oxidize or break under the deformation conditions of dynamic stretching, compression, shearing or bending, resulting in the deterioration of rubber physical properties. The aging form is mainly manifested as surface cracking and crack expansion. When using recycled rubber to produce rubber products, the rational use of chemical antioxidants in the formulation can significantly improve the fatigue resistance of rubber products. So which antioxidants are more beneficial to improve the fatigue resistance of rubber compounds? How to design a protection system?
1. The internal structure changes of reclaimed rubber after fatigue aging
In the process of using reclaimed rubber products, there are three structural changes due to fatigue: the weak bonds between the rubber molecules are destroyed, the rubber molecules are arranged in the direction of the force, the rubber phase around the carbon black becomes dense, and the physical and mechanical properties of the reclaimed rubber occur Changes, resulting in decreased fatigue resistance of reclaimed rubber products. Recycled rubber products will also generate heat during the fatigue aging process. The increase in the temperature of the rubber compound will accelerate the thermal aging. The role of force will also reduce the oxidation activation performance. Oxidation will also accelerate the fatigue damage process.
2. Which anti-aging agents can improve the fatigue resistance of rubber
Rubber antioxidants can effectively delay the aging time of rubber products, and different varieties of chemical antioxidants have different protective effects in rubber. The fatigue damage of reclaimed rubber products generally occurs on the surface of the products. The use of anti-aging agents that can quickly migrate in the vulcanized rubber network can significantly improve the fatigue resistance of reclaimed rubber vulcanized rubber. Recycled rubber products can work under fatigue conditions for a long time. P-phenylenediamine anti-aging agents such as 4010NA and anti-aging agent H have good protection against fatigue and aging. The universal anti-aging agent BLE can also significantly improve the fatigue resistance of reclaimed rubber.
3. Precautions to improve fatigue aging of reclaimed rubber
When using anti-aging agents in the formulation of recycled rubber products to improve the fatigue resistance of rubber compounds, rubber product manufacturers need to control the amount of anti-aging agent to avoid excessive amount of anti-aging agent 2LLYY514 to precipitate the surface of the product. In the actual production, rubber product manufacturers also need to take certain measures to prevent the antioxidant from volatilizing from the surface of the reclaimed rubber product or being washed away by the medium.
4. How to design protective system to improve the fatigue aging performance of rubber compound
The same kind of anti-aging agent has different protective effects in different kinds of reclaimed rubber products. Generally, the anti-aging agent with remarkable protective effect in latex reclaimed rubber and tire reclaimed rubber improves fatigue resistance of EPDM reclaimed rubber and butyl reclaimed rubber vulcanized rubber. The effect of aging performance is not obvious. At this time, rubber product manufacturers should choose to use anti-aging agents together. If necessary, use recycled rubber (such as latex recycled rubber and isoprene recycled rubber) in combination or combined vulcanization system to improve the fatigue resistance of recycled rubber. performance.
When using reclaimed rubber to produce rubber products and improve the fatigue resistance of rubber compounds through the protective system, rubber product manufacturers also need to consider the impact of other coordination systems on the protective effect of anti-aging agents. For example, the anti-aging agent has the best protective effect in sulfur vulcanizates, and the worst protective effect in peroxide vulcanizates. Later editors will continue to discuss with you how to further improve the fatigue resistance of reclaimed rubber through protection system design.