example, Kluppel et al. [17] studied the distribution of carbon black in
BR/ethylene–propylene–diene rubber blend and found that N550 carbon black
preferred to migrate into the BR phase. This is due to the higher degree of
unsaturation and lower viscosity of BR. Similarly, Hess et al. [18] studied carbon
black distribution in many natural rubber//synthetic rubber blends including
NR/CR, NR/NBR, and NR/SBR and found that carbon black preferentially resided
in the synthetic rubber phases having lower viscosity compared to natural rubber.
Recently, Jeon et al. [19] studied distribution of fillers in NR/BR blends by using
atomic force microscopy and found that carbon black resides predominantly in the
BR phase whereas silica mainly exists in the NR phase. Maiti et al. [20] studied the
distribution of carbon black and silica in NR/epoxidized NR (ENR) blends by using
DMTA technique. They found that silica migrated preferentially to the ENR phase.
It was believed that the reasons for the preferential migration of silica to the ENR
phase included the low viscosity of the ENR and a physical interaction between the
epoxide group of the ENR and the silanol group of the silica. In addition, they found
that the magnitude of the distribution depends on filler loading. When the silica
content was increased from 10 to 40 phr, the weight fraction of silica in the ENR
phase decreased. The viscosity of the ENR also plays an important role. By
increasing the epoxidation level of the ENR from 25 to 50 %, the viscosity of the
ENR phase was increased. This increase in viscosity of the ENR-50 inhibited the
migration of silica into the ENR phase.
1.3 Rubber-Rubber Blend Nanocomposites
In rubber-rubber blend nanocomposites, nanoparticles are incorporated into a blend
which can significantly affect the properties of the matrix. The properties of these
composites depend on the type of nanoparticles that are incorporated, their size and
shape, their concentration and their interactions with the polymer matrix. It is
difficult to produce monodispersed nanoparticles in a rubber blend because of the
agglomeration of nanoparticles. This problem can be overcome by modification of
the surface of the nanoparticles. Surface modification improves the interfacial
interactions between the nanoparticles and the polymer matrix. Nanofillers when
added to blend systems are known to cause a considerable change in dynamic
properties.
2 Nanofillers Used in Rubber Blend Reinforcement
The properties of rubber blend composites are determined by the particle size,
surface structure, and surface activity of filler. If the size of filler particles greatly
exceeds the polymer inter-chain distance, it introduces an area of localized stress.
This can contribute to elastomer chain rupture on flexing or stretching. Filler with
90
A.B. Nair et al.
BR/ethylene–propylene–diene rubber blend and found that N550 carbon black
preferred to migrate into the BR phase. This is due to the higher degree of
unsaturation and lower viscosity of BR. Similarly, Hess et al. [18] studied carbon
black distribution in many natural rubber//synthetic rubber blends including
NR/CR, NR/NBR, and NR/SBR and found that carbon black preferentially resided
in the synthetic rubber phases having lower viscosity compared to natural rubber.
Recently, Jeon et al. [19] studied distribution of fillers in NR/BR blends by using
atomic force microscopy and found that carbon black resides predominantly in the
BR phase whereas silica mainly exists in the NR phase. Maiti et al. [20] studied the
distribution of carbon black and silica in NR/epoxidized NR (ENR) blends by using
DMTA technique. They found that silica migrated preferentially to the ENR phase.
It was believed that the reasons for the preferential migration of silica to the ENR
phase included the low viscosity of the ENR and a physical interaction between the
epoxide group of the ENR and the silanol group of the silica. In addition, they found
that the magnitude of the distribution depends on filler loading. When the silica
content was increased from 10 to 40 phr, the weight fraction of silica in the ENR
phase decreased. The viscosity of the ENR also plays an important role. By
increasing the epoxidation level of the ENR from 25 to 50 %, the viscosity of the
ENR phase was increased. This increase in viscosity of the ENR-50 inhibited the
migration of silica into the ENR phase.
1.3 Rubber-Rubber Blend Nanocomposites
In rubber-rubber blend nanocomposites, nanoparticles are incorporated into a blend
which can significantly affect the properties of the matrix. The properties of these
composites depend on the type of nanoparticles that are incorporated, their size and
shape, their concentration and their interactions with the polymer matrix. It is
difficult to produce monodispersed nanoparticles in a rubber blend because of the
agglomeration of nanoparticles. This problem can be overcome by modification of
the surface of the nanoparticles. Surface modification improves the interfacial
interactions between the nanoparticles and the polymer matrix. Nanofillers when
added to blend systems are known to cause a considerable change in dynamic
properties.
2 Nanofillers Used in Rubber Blend Reinforcement
The properties of rubber blend composites are determined by the particle size,
surface structure, and surface activity of filler. If the size of filler particles greatly
exceeds the polymer inter-chain distance, it introduces an area of localized stress.
This can contribute to elastomer chain rupture on flexing or stretching. Filler with
90
A.B. Nair et al.