5.1 This test method is used to measure viscoelastic properties through the strain softening effects of a strain amplitude sweep (the Payne Effect).

5.2 For the uncured state, the time conditioning and strain amplitude strain sweeps can relate to colloidal silica particle or carbon black deagglomeration from the mixing process. The profile of this Payne Effect from G’ storage modulus can also be a function of loading levels and particle size of these fillers in the rubber hydrocarbon medium. In addition, with silica and an organosilane additive, this G’ strain softening effect can determine if a given silanization reaction between a subject silica and an organosilane was achieved through reactive mixing. If the silanization reaction during the mixing was not achieved, the maximum G’ storage modulus from the strain sweep will not be lowered and the silica particle attraction to other silica particles will still be high resulting in a more dense filler network that remains.

1.1 This test method covers the use of a sealed cavity rotorless oscillating shear rheometer for the measurement of the softening effects of rising sinusoidal strain when applied to an unvulcanized rubber compound containing significant amounts of colloidal fillers (such as silica or carbon black, or both) from a rubber mixing procedure. These strain softening properties relate to mixing conditions, the composition of the rubber compound, colloidal particle (Payne Effect) characteristics of the fillers, and in some cases the degree of reaction between an organosilane and precipitated, hydrated silica during mixing. This procedure is being commonly applied to rubber reactive mixing procedures.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.