Morphology of Composite Materials

The carbon blacks used in toughening elastomers such as tire rubber are extremely finely divided colloidal structures, usually about 10 nm in size, with 50 to 150 mVg of surface area. These carbon blacks have extremely active surfaces, containing hydrogen, hydroxyl, carboxyl, ester, and aldehyde groups, all capable of interacting with the elastomer to produce a series of weak bonds see Section 9.16.2. 

In tire manufacture a certain amount of aggregation produces optimum toughness. A major problem is keeping the carbon black properly dispersed among the several elastomers generally blended for the purpose. 

Some of the newest polymeric materials being discovered and developed are the nanocomposites. These materials broadly refer to composite components 

1 Definition and Generai Behavior of Nano-sized Structures 

Because of their small size, structures with nanoscale dimensions have relatively huge surface areas per unit weight, and these surface areas often dominate the behavior of these materials. Thus, the chemistry of the surfaces of these materials has taken on a special significance. 

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