Dispersion and Coupling Additives

The adhesion of filler and polymer can be enhanced by the use of coupling additives. In many industries it is often desirable to produce polymeric compounds in which fillers are well dispersed. For example, in the rubber industry it can be desirable to produce elastomeric compounds exhibiting reduced hysteresis when compounded with other ingredients, such as reinforcing fillers, and then vulcanized (4). 

The hysteresis of a rubber refers to the difference between the energy applied to deform the rubber and the energy recovered as the rubber returns to its initial, undeformed state. Interaction between 

Flours or fibers of other natural products Synthetic fibers 

Carbon black and silica are well known reinforcing fillers in rubber compounds and these, as well as other fillers, are often used as fillers for polymeric compounds in other industries, such as in thermoplastics, composites, paint, and the like. In rubber, attempts at improving filler dispersion have included high temperature mixing of carbon black-rubber mixtures in the presence of selectively-re-active promoters to promote compounding material reinforcement. Other approaches have, for example, included surface oxidation of the compounding materials or chemical modifications to the ter- 

Natural silicic acid Silicates Powdered talc Kaolinite Calcined clay 

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