The effect of increasing carbon black loading (N1100, DBPA = 112 and N990, DBPA = 41) on the storage modulus is given in figure 2.
2]/g) 124 143 Iodine (g/kg) 141 175 DBPA (mL/100g) 174 135 CDBPA (mL/100g) 130 102 Tint (%ITRB) 112 133 Transmission (%) 97 99
At 60 phr loading, the bound rubber was measurable only when the black had DBPA greater than 90 ml/100g.
2]/g as measures of area (particle size), DBPA (D2414) from 65 to 140cc/100g and CDBPA (D3493) from 61 to 90cc/100g as measures of aggregate structure and tint (D3265) from 46 to 64% ITRB as a measure of aggregate size.
Figure 1 shows a comparison of the loading effect on DL90, the change in torque with cure, for two blacks which span the range of DBPA, NS and EX2 black.
The only difference between the propylene and ethylene versions in low temperature is that NBR compounds with DBPA
and DBPPA are 2[degrees]C warmer than DBEA and DBEEA for the T-10 value, (low temperature torsion - Gehman - table 11) which is considered moderately significant.
The effective volume fraction, [phi]', of a carbon black in a rubber compound can be estimated from DBPA using the following equation developed by Medalia (ref.
eff] can be determined from either DBPA or compressed DBPA using equations 3 and 4.
2) have indicated that aggregate breakdown in rubber increases with increasing DBPA and diminishing NSA as shown by the following expression:
In the meantime, however, the V'/V data appear to give a more accurate representation for the relative levels of carbon black structure in these rubber compounds than either DBPA or compressed DBPA.
At very high loadings the inactive samples (partially graphitized) for the finer high DBPA grades gave higher tensile than untreated samples.
As shown in figure 6, no immobilized occluded rubber can be found until the DBPA
is higher than about 95.