The effect of surface properties and surface state of carbon black particles on reinforcement.

 

The surface chemistry of carbon black particles, the roughness of the surface of the particles, and the crystalline state of the carbon black all have a certain influence on the reinforcing effect. The sulfonium group or hydroquinone group on the surface of the carbon black can react chemically with the olefin rubber during the mixing and vulcanization of the carbon black to play a reinforcing role.

 

Fourth, the influence of carbon black variables on the reinforcement effect!

 

The content of carbon black in rubber can significantly affect the physical and mechanical properties of vulcanized rubber. Practice has shown that hardness, tensile strength and heat generation monotonically increase with the increase of carbon black. The rebound rate, elongation rate, etc. seem to decrease monotonously. The tensile strength, tear strength and abrasion resistance reach the maximum value with the increase of carbon black. The better the reinforcement, the more obvious the maximum value appears. As the amount of carbon black increases, the wear resistance of vulcanized rubber is significantly enhanced in the initial stage. After increasing to the maximum value, the carbon black increases again, and the wear resistance no longer changes significantly. When the total specific surface area of ​​carbon black in rubber is equal, carbon black with larger particles has better abrasion resistance, and smaller particles have poorer abrasion resistance. This is related to the dispersibility of carbon black in rubber. The smaller the particle size, the worse the dispersibility, thereby reducing the wear resistance.

 

The amount of carbon black also has a significant effect on the conductivity of vulcanized rubber. When the dosage is increased, the resistivity of the vulcanized rubber decreases significantly.

 

5. Process performance of carbon black and rubber,

 

The basic properties of carbon black and its effect on the mixing of carbon black rubber are very significant. Due to the different properties of carbon black, the mixing speed and dispersion effect of carbon black are also different, and the Mooney viscosity of various carbon blacks is also different. The powder intake rate of carbon black in rubber is closely related to particle size and structure. The smaller the particle size, the higher the structure, and the longer the mixing time required. Carbon black has small particle size, low structure, poor dispersion and long mixing time. Compared with high wear-resistant carbon black, channel black has a poor dispersion effect. Due to the low structure of channel black, the difference in particle size between the two is not much.

 

The carbon black kneading glue is placed in a solvent, and there are partially insoluble gel particles. It is a combination of carbon black and rubber, which is called carbon black glue or adhesive glue. The amount of carbon black gel produced is related to the type and amount of carbon black, the type of rubber, and the mixing conditions. The amount of carbon black gel produced is an important indicator to measure the reinforcing effect of carbon black on rubber. Gel is a kind of rubber macromolecule. After it is destroyed, it combines with carbon black and captures the hydrogen atoms of carbon black to form the chemical bond of rubber and carbon black and the physical bond of mutual adsorption. Similar network combinations are formed through the combination of chemistry and physics. The particle size and structure of carbon black have a significant impact on the ability to form a gel, and have a greater impact on the degree of structure. The smaller the particle size, the higher the degree of structure, and the easier it is to form a gel. Carbon black is more likely to be produced than carbon black with a particle size of high abrasion resistance. It is more pronounced in rubbers with low unsaturation. The amount of gel produced varies depending on the type of rubber. Natural gel, styrene butadiene rubber, butadiene and neoprene rubber produce more gel than styrene butadiene and butadiene rubber. The low unsaturation of butyl and ethylene propylene is almost impossible to form a carbon black gel. The temperature of the rubber is also closely related to the amount of carbon black gel. At high temperatures, the gel is promoted. During the mixing process, the carbon black gel can continue to form in the rubber. The higher the temperature. The faster the gel content increases. The Mooney viscosity of the rubber compound has a lot to do with the rubber processing technology, and the rubber compound with high Mooney viscosity often causes processing difficulties. The viscosity change of the carbon black compound is directly related to the carbon black gel. The larger the gel in the carbon black compound, the higher the Mooney viscosity of the compound. The finer the carbon black particle size, the higher the structure, the higher the dosage, and the higher the viscosity of the rubber compound. The reason is that these factors promote the formation of gel. The higher the temperature. The faster the gel content increases. The Mooney viscosity of the rubber compound has a lot to do with the rubber processing technology, and the rubber compound with high Mooney viscosity often causes processing difficulties. The viscosity change of the carbon black compound is directly related to the carbon black gel. The larger the gel in the carbon black compound, the higher the Mooney viscosity of the compound. The finer the carbon black particle size, the higher the structure, the higher the dosage, and the higher the viscosity of the rubber compound. The reason is that these factors promote the formation of gel. The higher the temperature. The faster the gel content increases. The Mooney viscosity of the rubber compound has a lot to do with the rubber processing technology, and the rubber compound with high Mooney viscosity often causes processing difficulties. The viscosity change of the carbon black compound is directly related to the carbon black gel. The larger the gel in the carbon black compound, the higher the Mooney viscosity of the compound. The finer the carbon black particle size, the higher the structure, the higher the dosage, and the higher the viscosity of the rubber compound. The reason is that these factors promote the formation of gel. However, high Mooney viscosity compounds often cause processing difficulties. The viscosity change of the carbon black compound is directly related to the carbon black gel. The larger the gel in the carbon black compound, the higher the Mooney viscosity of the compound. The finer the carbon black particle size, the higher the structure, the higher the dosage, and the higher the viscosity of the rubber compound. The reason is that these factors promote the formation of gel. High Mooney viscosity compounds often cause processing difficulties. The viscosity change of the carbon black compound is directly related to the carbon black gel. The larger the gel in the carbon black compound, the higher the Mooney viscosity of the compound. The finer the carbon black particle size, the higher the structure, the higher the dosage, and the higher the viscosity of the rubber compound. The reason is that these factors promote the formation of gel. The higher the structure and the higher the dosage, the higher the viscosity of the compound. The reason is that these factors promote the formation of gel. The higher the structure and the higher the dosage, the higher the viscosity of the compound. The reason is that these factors promote the formation of gel.