Chapter 2
Filler and Rubber Reinforcement
Abstract In a sense, rubber reinforcement is very unique because it includes several functional properties other than mechanical ones. Among quite a number of
compounding ingredients, reinforcing fillers, carbon black (CB) in particular, were
focused in 1930s, and the effect has been actively researched for several decades.
Ability of CB to immobilize rubber on its surface (known as bound rubber, CB-torubber interaction) and clustering tendency of CB in rubber matrix (known as CB
structuring, filler-to-filler interaction) have been recognized and studied for many
years. Together with the third, hydrodynamic volume effect, the three factors have
been extensively researched, but the acting mechanism of the three factors for rubber
reinforcement has remained unsolved up to the end of the twentieth century. This
chapter presents the most recent elucidations related to the reinforcement mechanism.
Keywords Reinforcing effect · Rubber compounding · Bound rubber · Structuring
of nanofiller · Hydrodynamic volume effect
2.1 Reinforcing Effect
Generally speaking, increase of the strength at break is specifically assumed to be a
fundamental factor in reinforcement of materials. As already explained in Chap. 1,
however, reinforcement effect of rubber includes not only the mechanical improvements, but also betterment of several functional behaviors. For example, those on the
pneumatic rubber tire were already explained by the unrivaled influence of carbon
black (CB) on the top tread rubber of tires among so many rubber products. Due to the
space limit, however, details of such functionality improvements in various rubber
products are not included in this book. For such detailed information, check Refs.
[1–12] and/or relevant handbooks or data compilations distributed by the industrial
organizations specific to each rubber product, if available.
In some rubber products, a cheap particle (sometimes called ‘filler,’ too) is intentionally mixed. If the mixing would neither make rubber processing more difficult
nor deteriorate property of the final product so much as to give inconvenience to its
usage, the product could be on the market as a cheaper alternative. Economically,
© Springer Nature Singapore Pte Ltd. 2020
S. Kohjiya et al., Reinforcement of Rubber, Springer Series on Polymer
and Composite Materials, https://doi.org/10.1007/978-981-15-3789-9_2
13
Filler and Rubber Reinforcement
Abstract In a sense, rubber reinforcement is very unique because it includes several functional properties other than mechanical ones. Among quite a number of
compounding ingredients, reinforcing fillers, carbon black (CB) in particular, were
focused in 1930s, and the effect has been actively researched for several decades.
Ability of CB to immobilize rubber on its surface (known as bound rubber, CB-torubber interaction) and clustering tendency of CB in rubber matrix (known as CB
structuring, filler-to-filler interaction) have been recognized and studied for many
years. Together with the third, hydrodynamic volume effect, the three factors have
been extensively researched, but the acting mechanism of the three factors for rubber
reinforcement has remained unsolved up to the end of the twentieth century. This
chapter presents the most recent elucidations related to the reinforcement mechanism.
Keywords Reinforcing effect · Rubber compounding · Bound rubber · Structuring
of nanofiller · Hydrodynamic volume effect
2.1 Reinforcing Effect
Generally speaking, increase of the strength at break is specifically assumed to be a
fundamental factor in reinforcement of materials. As already explained in Chap. 1,
however, reinforcement effect of rubber includes not only the mechanical improvements, but also betterment of several functional behaviors. For example, those on the
pneumatic rubber tire were already explained by the unrivaled influence of carbon
black (CB) on the top tread rubber of tires among so many rubber products. Due to the
space limit, however, details of such functionality improvements in various rubber
products are not included in this book. For such detailed information, check Refs.
[1–12] and/or relevant handbooks or data compilations distributed by the industrial
organizations specific to each rubber product, if available.
In some rubber products, a cheap particle (sometimes called ‘filler,’ too) is intentionally mixed. If the mixing would neither make rubber processing more difficult
nor deteriorate property of the final product so much as to give inconvenience to its
usage, the product could be on the market as a cheaper alternative. Economically,
© Springer Nature Singapore Pte Ltd. 2020
S. Kohjiya et al., Reinforcement of Rubber, Springer Series on Polymer
and Composite Materials, https://doi.org/10.1007/978-981-15-3789-9_2
13