The dynamics of cross-linked filled rubbers has huge significance to the energy dissipation mechanisms that contribute to 80% of the carbon footprint in the life-cycle of a car tyre. In this new STFC-funded PhD scholarship (global challenge - futures project) we address the sources of energy dissipation using scattering techniques. Here, we will quantify the influence cross linker separately before addressing the more complex systems that contain both cross links and fillers. We will study five different levels of cross linker in a high molecular weight polybutadiene, such that the average separation between cross-linked points is systematically varied over the relevant scales of this polymer. We will study cross linker densities from zero cross linker up to the point at which polymer segments between cross-links are comparable to the entanglement molecular weight