Effect of Functionalization of Carbon Black on Rubber Properties

Introduction
The tire industry requires continuous development in the areas <strong>of</strong>
• Increased durability;
• Better fuel economy; and
• Improved safety.
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CRX4XXX-012-FTF’01-Simp.doc
These requirements can only be met by improvement <strong>of</strong> wear resistance, rolling
resistance and skid resistance, especially in wet conditions. From the compounding point
<strong>of</strong> view, it has been recognized that the filler and polymer play an equally important role
in governing the compound properties, thus tire performance. In fact, the term filler is
misleading as it implies a material that increases the volume and reduces the compound
cost. Additionally, the filler cannot only be considered to be what is commonly referred
to as a “reinforcing agent” in the sense <strong>of</strong> a material that increases modulus and improves
the tensile strength <strong>of</strong> the compound. What is commonly referred to as “filler” is actually
a functional material or component which has a significant effect on tire performances.
It has been well established that the wear resistance <strong>of</strong> filled rubber is essentially
determined by the polymer-filler interaction. For fillers having similar morphologies, the
increase in polymer-filler interaction, either through enhancement <strong>of</strong> physical adsorption
<strong>of</strong> polymer chains on the filler surface or via creation <strong>of</strong> chemical linkages between filler
and polymer, is crucial to the enhancement <strong>of</strong> wear resistance.
It has also been established that there is a good correlation between the rolling resistance
<strong>of</strong> tires and the hysteresis <strong>of</strong> the tread compound, characterized by the loss factor, tan δ,
at high temperature. The hysteresis is in turn determined by the filler networking which is
governed by polymer-filler, and especially filler-filler interactions. 1 The stronger the
filler-filler interaction, the more developed is the filler network, hence the higher the
rolling resistance <strong>of</strong> tires.
In the last few years, in response to ever more demanding requirements from the tire
industry, a great effort has been made by Cabot Corporation to develop functionalized