Fillers predominantly used in the rubber industry

Fillers have been used in the formulation of rubber compounds since the early days of the rubber industry. Whilst their primary function is to reduce cost, it has been found that fillers have a reinforcing effect in the rubber mechanical properties sueh as tensile strength, modulus, tear resistance and abrasion resistanee and thus very few mbber compounds are prepared without substantial quantities of filler. The performance of filler in the rubber matrix is governed by its characteristics, such as the particle size and concentration, particle shape, surface activity, degree of interactions with rubber matrix and structure of the particle agglomerates. 

The incorporation of CB with high surface area in an elastomer results in a high level of reinforcement and higher tensile strength, tear strength, and abrasion resistance, but also results in a compound with high hysteresis, high cost, and one 

Synthetic silicon dioxide (siUea) can be produced either by precipitation or by a pyrogenic (thermal) proeess. According to the method of production, synthetic silicon dioxide ean be classified into two groups precipitated and pyrogenic (fumed) silica. Precipitated silicas have been used extensively in many mbber applications, much more than fumed silica. In the mbber industry, the use of fumed silicas is limited due to expense, mainly being used as reinforcing fillers for silicon mbbers. Non-black fillers such as silica are chosen over CB for one or more of the following reasons  

Silica is thus the most important filler that competes with carbon black in the area of mbber reinforcement technology. However, in the early stages of silica usage, their uses as reinforcing filler instead of carbon black were limited due to a number of problems 

The silanol groups, which are on the surface of silica, show strong filler-filler interactions and cause the adsorption of the polar materials such as the curatives 

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