Factors affecting the resilience and vulcanization speed of vulcanized rubber and solutions
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I personally think that the factors and solutions that affect the rubber resilience and vulcanization speed can be carried out from the following aspects:
① The vinyl content in the rubber is not enough or the vinyl content of the raw rubber is not uniformly distributed, so that the rubber does not reach the normal sulfur point during vulcanization, the vulcanization speed is longer, and the vulcanization is insufficient, resulting in poor rubber elasticity. You can solve the problem of poor resilience and slow vulcanization by increasing the overall vinyl content in the rubber, and adding an appropriate amount of hydrogen-containing silicone oil to the formula, reducing the amount of filler and increasing the rubber content; also different models can be used. Raw rubber with vinyl content, used in combination with a small amount of high vinyl raw rubber to control the permanent deformation of the rubber. To find an optimal balance point in the formula, to avoid the brittleness of the rubber, to improve Purpose of rubber elasticity.
② The rubber itself is acidic, which is also an important factor that leads to poor rubber resilience and slow vulcanization speed. As the white carbon black itself is acidic, and the added structure control agents are mostly acidic, the rubber is acidic. The acidic rubber has a delayed effect on vulcanization, and the high temperature resistance will decrease. The acid content of the rubber compound can be improved by adding appropriate weak alkaline substances. Generally, the pH value of the rubber compound in the neutral or weak alkaline range is good for improving the elasticity and vulcanization speed.
③Other aspects: too much plasticizer or structure control agent is added to the rubber compound, which results in poor rubber resilience and slow vulcanization speed; too much plasticizer or structure control agent is added to the rubber compound, which has a negative effect on the rubber compound Delayed vulcanization, resulting in poor rubber resilience and slow vulcanization speed. Raw rubber with a narrow molecular weight distribution and a certain volatile content can be used to improve the demolding of the rubber, thereby reducing the amount of plasticizer; use The surface of silica is treated by alkoxysilane and used in combination with hydroxy silicone oil. The two-step method is used to allow silica and rubber molecules to have a certain reaction time. Health can be taken in the process to reduce the structure control agent. Dosage can achieve the purpose of improving rubber resilience and vulcanization speed.
At the same time, the establishment of a standard vulcanization curve for each type of rubber is also a way to control the stable production quality of the mixed rubber.