A Model Compound Study About Carbon Black and Diene Rubber Interaction: The Reactivity of C60Fullerene with Squalene

Abstract

The reaction between squalene and C₆₀ fullerene was studied by electronic and FT-IR spectroscopy as well as by thermal analysis (TGA and DTA). This study was conducted to simulate in vitro, with model compounds, the interaction occuring during mixing between dienic rubber and carbon black. Squalene was used as model compound for dienic rubber and C₆₀ fullerene as model compound for carbon black since fullerene-like sites have been recently identified on carbon black surface. The experimental results show that 2,5 molecules of C₆₀ become chemically bound to each squalene molecule under thermo-oxidative conditions simulating part of the mixing cycle between rubber and carbon black. The implications of this result involve the explanation of the phenomenon known as “bound rubber”, which is the amount of chemisorbed polymer on filler surface after mixing, as well as the reinforcement effects observed by filling rubber with carbon black and the mechanical hysteresis of a rubber compound.