Interaction between functional groups of E Series polymer and silanol groups at silica surface.

Enhanced silica dispersion Increased proportion of bound rubber Reduced silane coupling agent requirement

Silica/polymer blending

Short dispersion time due to interaction with silica surface

Test method   Silica and model compound containing functional group or hydrocarbon compound dispersed in decalin solvent at 150°C, followed by determination of the proportion of the compound adsorbed onto or reacted with silica at various times, which is taken as the reaction ratio.

Fine silica dispersion, high retention of elasticity

In formulations and blends with the E Series polymers, the fine silica dispersion induced by their functional groups results in lower inherent rigidity and thus greater elasticity, and a smaller Payne effect and thus a smaller loss of elastic strength with strain. During the blending and production of silica compound rubber, silica agglomerates tend to form due to the inherent cohesive ("secondary", attractive) force between the silica particles, tending to increase its rigidity or "storage modulus". Later, when strain occurs in the rubber, these agglomerates are disrupted, thereby reducing its rigidity. The E Series induces an extremely fine silica dispersion, resulting in greater inherent elasticity and a substantially reduced Payne effect, as shown below in terms of storage modulus.

a: Polymer having no functional groups. b: Polymer having functional groups, as in E Series.

Please note that all data and values are given as typical results obtained with the indicated test methods for purposes of basic reference only and not as any product specification or warranty of any nature, and are subject to change without notice.

For further information on these Asahi Kasei products, please contact us.