Further Documenting Carbon Black – Rubber Interactions Through Large Amplitude Oscillating Shear (LAOS) Testing and the Adequate Mathematical Modeling of Results

The concept of topological constraints refers to the strong interactions that spontaneouly develop when a rigid material with an appropriate surface geometry (or topology) comes into contact with a soft polymer-type material that has the capability to conform its components (i.e. chain segments) with this surface. Applied to carbon black filled rubber compounds, this concept means that a number of measurable bulk properties such as viscosity and/or modulus readily reflect an adsorption-desorption balance of chain segments on appropriate sites on CB aggregates. With respect to either strain magnitude or temperature or both, this balance may be affected in a reversible manner and relatively simple mathematical models can be developed to treat measured quantities that are directly related to CB-rubber interactions. Owing to their experimental simplicity, strain sweep test protocols with suitable dynamic rheometers are particularly attractive in this respect, as will be demonstrated through experiments on a series of carbon black filled compounds and the adequate mathematical modeling of results gathered when playing with the strain amplitude and the temperature.