4
1 Rubbery Materials and Soft Nanocomposites
applications [2–12]. We are now living in a transportation society [1, 3], and we often
watch pneumatic (i.e., pressured air-filled) rubber tires, the rubber components of
which are reinforced with CB as well as cross-linked. The two outstanding technical
issues of rubber would remain to be of utmost importance to the end of this century,
or well into the twenty-second century [3, 12] (see also Chap. 9 of the present
book, for rubber reinforcement from the viewpoints of globalization and sustainable
development).
Here, a retrospective view of the relationship between CB and rubber is given at
first: This combination has incidentally suggested certain compatibility of CB with
rubber to afford an interesting reinforcement effect on rubber vulcanizates. Unique
rubber elasticity, a mechanical property of rubber, is found to provide us with several
functional properties in practice, when applied to rubber tires [1–3, 8, 12]. Namely
the functional property of top tread rubber of tires includes lots of dynamic properties
such as traction (transmission of driving and braking forces to the road surface), grip
of the road surface, rolling resistance, skid (movement of tire under no rotation)
resistance, wear of the contacting rubber layer on the road surface, and so on. These
are not much related to mechanical strength but more or less to friction (both dynamic
and static) and abrasion/wear phenomena. Both interestingly and importantly, the
compounding of CB into rubber enables us to control these indispensable properties
of tire rubber as well as mechanical properties. In consequence, ‘reinforcement’
of rubber is not simply relevant to mechanical issues, but to several dynamic and
functional properties controlling the driving capability of automobiles. This is an
outstanding difference from the reinforcement of polymer by a composite formation
in general.
Additionally, the affinity of rubber with CB as mentioned above has been found in
other nanofillers, e.g., particulate silica. Hence, the specific functional performance of
rubber vulcanizates compounded with nanofillers has been recognized among rubber
scientists and engineers for long. It is notable here that nanoparticles, including CB
and particulate silica, have relatively huge surface area, and the interaction between
two nanoparticles is very strong. Consequently, they are destined to cluster each
other due to the Van der Waals force. The nanofiller-loaded rubber vulcanizate is
to be regarded as a representative soft nanocomposite to be a material of choice for
pneumatic tires in the present transportation society [3, 12], which is more detailed
in the later chapters.
With such perspective and prospective views, this chapter is going to give a general
introduction to the main parts of this book on rubber ‘reinforcement.’
1.2 Carbon Black-Loaded Natural Rubber Vulcanizate:
The Pioneer of Polymer Composite
The industrial manufacturing of the soot is originated from Hydro Carbon Gas Black
Co. in 1872, which commercialized it under the name of ‘Carbon Black.’ They used
natural gas as the starting material (traditionally, pine trees have been employed for
1 Rubbery Materials and Soft Nanocomposites
applications [2–12]. We are now living in a transportation society [1, 3], and we often
watch pneumatic (i.e., pressured air-filled) rubber tires, the rubber components of
which are reinforced with CB as well as cross-linked. The two outstanding technical
issues of rubber would remain to be of utmost importance to the end of this century,
or well into the twenty-second century [3, 12] (see also Chap. 9 of the present
book, for rubber reinforcement from the viewpoints of globalization and sustainable
development).
Here, a retrospective view of the relationship between CB and rubber is given at
first: This combination has incidentally suggested certain compatibility of CB with
rubber to afford an interesting reinforcement effect on rubber vulcanizates. Unique
rubber elasticity, a mechanical property of rubber, is found to provide us with several
functional properties in practice, when applied to rubber tires [1–3, 8, 12]. Namely
the functional property of top tread rubber of tires includes lots of dynamic properties
such as traction (transmission of driving and braking forces to the road surface), grip
of the road surface, rolling resistance, skid (movement of tire under no rotation)
resistance, wear of the contacting rubber layer on the road surface, and so on. These
are not much related to mechanical strength but more or less to friction (both dynamic
and static) and abrasion/wear phenomena. Both interestingly and importantly, the
compounding of CB into rubber enables us to control these indispensable properties
of tire rubber as well as mechanical properties. In consequence, ‘reinforcement’
of rubber is not simply relevant to mechanical issues, but to several dynamic and
functional properties controlling the driving capability of automobiles. This is an
outstanding difference from the reinforcement of polymer by a composite formation
in general.
Additionally, the affinity of rubber with CB as mentioned above has been found in
other nanofillers, e.g., particulate silica. Hence, the specific functional performance of
rubber vulcanizates compounded with nanofillers has been recognized among rubber
scientists and engineers for long. It is notable here that nanoparticles, including CB
and particulate silica, have relatively huge surface area, and the interaction between
two nanoparticles is very strong. Consequently, they are destined to cluster each
other due to the Van der Waals force. The nanofiller-loaded rubber vulcanizate is
to be regarded as a representative soft nanocomposite to be a material of choice for
pneumatic tires in the present transportation society [3, 12], which is more detailed
in the later chapters.
With such perspective and prospective views, this chapter is going to give a general
introduction to the main parts of this book on rubber ‘reinforcement.’
1.2 Carbon Black-Loaded Natural Rubber Vulcanizate:
The Pioneer of Polymer Composite
The industrial manufacturing of the soot is originated from Hydro Carbon Gas Black
Co. in 1872, which commercialized it under the name of ‘Carbon Black.’ They used
natural gas as the starting material (traditionally, pine trees have been employed for