The Mooney viscosity of CSDPF 4210-based compounds is influenced by silane coupling agent dosages.
The high Mooney viscosity of CSDPF 4210-based compounds without a coupling agent is, however, quite surprising, since, as will be discussed later, CSDPF 4210-based compounds exhibit a very low Payne effect even when no coupling agent is present.
The cure characteristics of CSDPF 4210-based compounds were found to vary with CSDPF 4210 filler loading when the same cure package was used.
There is about a four-unit difference in the room temperature hardness between carbon black- and CSDPF 4210-based compounds.
The storage modulus at both 0 and 70 [degrees] C of CSDPF 4210-based compounds without silane coupling agents is compared with that of silica/carbon black blend-based compounds in figure 3.
It is worthwhile to note that CSDPF 4210-based compounds without a silane coupling agent show very low [DELTA]G' values that approach the lowest exhibited by the silica/carbon black blend system, a clear indication of weak filler-filler interaction in CSDPF 4210-based compounds.
Filler-filler interaction is further depressed and filler-polymer interaction enhanced in CSDPF 4210-based compounds when a coupling agent is introduced as revealed, from an even lower Payne effect, as shown in figure 5.
Weak filler-filler interaction and strong filler-polymer interaction via strong adsorption of elastomer molecules on the CSDPF 4210 surface and through strong coupling reaction would be expected to lead to compounds with low hysteretic loss at high temperatures.
As is with other types of reinforcing fillers, the high-temperature hysteretic properties of CSDPF 4210-based compounds are influenced by filler loading.
The close match of hysteretic properties between CSDPF 4210- and silica-based compounds indicates CSDPF 4210-based compounds would give rise to tires with rolling resistance performance comparable with silica-based tires.
As is shown in figure 6, CSDPF 4210-based compounds exhibit high hysteretic loss at low temperatures (<0 [degrees] C), similar to silica-based corn pounds.
To further assess wet skid resistance of CSDPF 4210-based compounds, other than low-temperature dynamic properties, a modified British Portable Skid Tester (BPST) was used to measure the friction force between rubber compounds and a sandblasted glass plate considered to be a model road surface under wet conditions.