Molecular Dynamics of Silica and Organoclay Filled XNBR-Nanocomposites

To evaluate the effects of nanostruc-tured fillers like organoclay and silica on polymer dynamics close to filler interfaces a carboxylated nitrile rubber was investigated by dielectric and dynamic-mechanical spectroscopy. Three relaxation processes have been detected. The relaxation processes at low and medium temperatures can be assigned to the β-process and the glass transition, respectively. The relaxation process at high temperatures is due to the formation ofzinc-carboxyl-clusters. This process increases with the loading of organoclay and shifts to higher temperature. With silica the process stays at the same position and is only slightly increasing in strength. Both effects indicate that the two types of fillers exhibit differences in polymer filler interaction and filler networking.