6
1 Rubbery Materials and Soft Nanocomposites
In addition, Mote’s achievement might be strengthened by the efforts of G.
Oenslager (1873–1956) at Diamond Rubber Co. He was pioneering the use of organic
accelerators in combination with sulfur for rubber vulcanization [15]. It is well known
that the development of sulfur cross-linking (i.e., vulcanization) technique has been
in close mutual correlation with rubber reinforcement [2–12, 15]. For instance, the
shift of CB from gas carbon (manufactured by the channel method) to furnace carbon
(manufactured by the furnace method established in the 1940s: HAF and ISAF are
the representative grades) in rubber industry was followed by the change of organic
accelerators to the delayed-type ones, too. Recently, a new mechanism of the vulcanization reactions is reported [16–21], and if this mechanism is found to be exactly the
case, some features of rubber reinforcement are going to be modified accordingly.
From the scientific point of view, reinforcement and vulcanization are independent,
but in practice the two are mutually related in the arena of rubber processing technics.
The second factor, idea of combining rubber with a fiber material, commonly
called a tire cord, has been applied and practiced in polymeric materials as well as in
rubber industry. Among them, fiber reinforced plastics (FRP) is now widely known
as an example of composite material [22]. In other words, demand for pneumatic
rubber tires has provided us with an innovative new soft composite of much higher
performance from polymer and fiber, too. In rubber processing, the two pairs, i.e.,
rubber/nanofiller and rubber/fiber cord have been skillfully combined, which has
been an essential technical core in rubber manufacturing industries until the present
time. Rubber tires and rubber belts are typical examples.
The pneumatic rubber tire is an elastic device, i.e., a soft container of the pressured air, supporting automobiles or aircraft on the road surface [1–3, 11]. Mechanical strength enough to support a heavy object such as the automobile or airplane
is obtained in combination with fiber materials. On the other hand, the effects of
compounding CB into rubber are not limited to mechanical properties [2, 3, 11, 17].
In addition to mechanical strength, the function of top tread rubber of tires, which is
always in contact with the road surface, suggests much more complex yet amazingly
lucid features during driving (in the case of aircraft, also taxying), that is, traction,
grip, high skid resistance even under rainy conditions, low rolling resistance, appropriate abrasion or wear of their surface in touch with the road surface, deterrence of
hydroplaning when driving under rain at a higher speed, and so on.
Separately from those, heat buildup is a big challenge for tire rubbers from a
chemical point of view. When driven, tires are under high-speed rotation on the road
surface, which results in much heat generation due to dynamic friction leading to
heat buildup of the tire. The temperature increase of the tire has to be arrested by the
dissipation of heat due to air cooling. During driving, the competition of two factors,
heat by friction and air cooling, results in an equilibrium temperature of tire, which
is to be as low as possible, of course, for the safety driving and longer lifetime of tire
rubbers. Note that this equilibrium temperature has to be absolutely lower than the
melting temperature of fiber cords used in the tires. The temperature may be highly
dependent on lots of internal structural details as well as the thermal stability of used
materials. In addition, external conditions matter, which include driving conditions
(driving speed, duration time of the speed, etc.), climate conditions (atmospheric
1 Rubbery Materials and Soft Nanocomposites
In addition, Mote’s achievement might be strengthened by the efforts of G.
Oenslager (1873–1956) at Diamond Rubber Co. He was pioneering the use of organic
accelerators in combination with sulfur for rubber vulcanization [15]. It is well known
that the development of sulfur cross-linking (i.e., vulcanization) technique has been
in close mutual correlation with rubber reinforcement [2–12, 15]. For instance, the
shift of CB from gas carbon (manufactured by the channel method) to furnace carbon
(manufactured by the furnace method established in the 1940s: HAF and ISAF are
the representative grades) in rubber industry was followed by the change of organic
accelerators to the delayed-type ones, too. Recently, a new mechanism of the vulcanization reactions is reported [16–21], and if this mechanism is found to be exactly the
case, some features of rubber reinforcement are going to be modified accordingly.
From the scientific point of view, reinforcement and vulcanization are independent,
but in practice the two are mutually related in the arena of rubber processing technics.
The second factor, idea of combining rubber with a fiber material, commonly
called a tire cord, has been applied and practiced in polymeric materials as well as in
rubber industry. Among them, fiber reinforced plastics (FRP) is now widely known
as an example of composite material [22]. In other words, demand for pneumatic
rubber tires has provided us with an innovative new soft composite of much higher
performance from polymer and fiber, too. In rubber processing, the two pairs, i.e.,
rubber/nanofiller and rubber/fiber cord have been skillfully combined, which has
been an essential technical core in rubber manufacturing industries until the present
time. Rubber tires and rubber belts are typical examples.
The pneumatic rubber tire is an elastic device, i.e., a soft container of the pressured air, supporting automobiles or aircraft on the road surface [1–3, 11]. Mechanical strength enough to support a heavy object such as the automobile or airplane
is obtained in combination with fiber materials. On the other hand, the effects of
compounding CB into rubber are not limited to mechanical properties [2, 3, 11, 17].
In addition to mechanical strength, the function of top tread rubber of tires, which is
always in contact with the road surface, suggests much more complex yet amazingly
lucid features during driving (in the case of aircraft, also taxying), that is, traction,
grip, high skid resistance even under rainy conditions, low rolling resistance, appropriate abrasion or wear of their surface in touch with the road surface, deterrence of
hydroplaning when driving under rain at a higher speed, and so on.
Separately from those, heat buildup is a big challenge for tire rubbers from a
chemical point of view. When driven, tires are under high-speed rotation on the road
surface, which results in much heat generation due to dynamic friction leading to
heat buildup of the tire. The temperature increase of the tire has to be arrested by the
dissipation of heat due to air cooling. During driving, the competition of two factors,
heat by friction and air cooling, results in an equilibrium temperature of tire, which
is to be as low as possible, of course, for the safety driving and longer lifetime of tire
rubbers. Note that this equilibrium temperature has to be absolutely lower than the
melting temperature of fiber cords used in the tires. The temperature may be highly
dependent on lots of internal structural details as well as the thermal stability of used
materials. In addition, external conditions matter, which include driving conditions
(driving speed, duration time of the speed, etc.), climate conditions (atmospheric