Contribution of fine filler particles to energy dissipation during wet sliding of elastomer compounds on a rough surface

Abstract

Elastomer compounds reinforced with precipitated silica can exhibit elevated wet sliding friction on a rough surface in comparison with corresponding compounds filled with carbon black particles. The underlying mechanism is currently not well understood. To unravel this puzzling observation, the variation of wet sliding friction with filler volume fraction is examined at the sliding speed of the order of 1 m s−1 under different lubrication conditions. Depending on the lubrication liquid—water or ethanol—a compound that shows both higher bulk hysteretic loss and lower modulus does not always exhibit a higher wet sliding friction. A thorough characterization of the bulk rheology of the compounds investigated fails to provide the rationale for such behaviour, thus constituting an apparent violation of the conventional viscoelastic understanding of rubber friction on a rough surface. On the other hand, the detected lowering of friction when the lubrication liquid is changed from water to ethanol resembles the effect of liquid medium on interfacial adhesion reported in the literature. Hence, it is suggested that a stronger interfacial attractive interaction should exist in water between the road surface and silica particles on the compound surface immediately next to the road surface. This should be related to the elevated wet sliding friction detected for silica-filled compounds under water lubrication.

Effect of 3‐propionylthio‐1‐propyltrimethoxylsilane on structure, mechanical, and dynamic mechanical properties of NR/silica composites

“…It greatly improves the mechanical properties of the vulcanizates such as tensile strength, tear resistance, abrasion resistance, and hardness [1][2][3]. Particularly, the use of silane-treated silica in tire tread gives improvement in rolling resistance, wear resistance, and wet traction [4]. However, silica contains a large number of silanol (SiÀ ÀOH) groups on the surface.…”

Synthesis and characterization of 3‐benzothiazolthio‐1‐propyltriethoxylsilane and its reinforcement for styrene–butadiene rubber/silica composites

“…Such behavior of silica in rubber have always been associated with its weak polymer–filler interactions and strong filler–filler interactions, both are mainly attributed to the siloxane and silanol groups on silica surface. Recently, the modification of silica surface with sulfur‐containing silane coupling agents has aroused a significant amount of interest because they are able to enhance rubber–filler interaction via chemical linkage 1–4. Sulfur‐containing silane coupling agents contain one or more of the following chemical bond types: SH (mercapto), SS (disulfide or polysulfide), OCS (carbonylthio), etc.…”

“…Recently, the modification of silica surface with sulfur-containing silane coupling agents has aroused a significant amount of interest because they are able to enhance rubber-filler interaction via chemical linkage. [1][2][3][4] Sulfur-containing silane coupling agents contain one or more of the following chemical bond types: SAH (mercapto), SAS (disulfide or polysulfide), O¼ ¼CAS (carbonylthio), etc. They possess two functionally active end groups that can produce chemical bonding between silica and rubber.…”

Role of Material Composition in the Construction of Viscoelastic Master Curves: Silica-Filler Network Effects

“…Traction, especially under wet conditions, is the most important tire property from a safety point of view. Traction is directly related to energy lost in each deformation cycle: each point in the tire passes through a stress-strain cycle once every rotation [1][2][3][4][5][6][7] . Due to the viscoelastic nature of the rubber compound, the deformation leads to energy loss in the form of heat in each cycle.…”