Interaction of Siloxane Polymers and Silica
Ian Weatherhead (previous student, left the group in 1998)
This project concerns the interaction of organosilicon polymers with inorganic fillers which are of importance for the manufacture of composite materials. These interactions are believed to determine the bulk properties of such materials.
Chemical Structure of Poly(dimethylsiloxane)
The aim is to elucidate the conformation of poly(dimethylsiloxane) (PDMS)chains which are physically adsorbed or chemically grafted to a silica surface and dispersed in a PDMS melt.
Schematic of the different types of hydroxyl groups on a silica surface
Initial work concentrated on commercial fumed silica aggregates, however current experiments are considering discrete monodisperse precipitated silica particles. The influence of silica surface chemistry on the interfacial layer is of particular interest. Initial rheological measurements have been used to study the bulk physical properties. Nuclear Magnetic Resonance (NMR) allows the study of interactions of the interfacial layers with the bulk melt and their dynamics. This approach uses NMR relaxation and self-diffusion experimental techniques.Small-angle neutron scattering is being used to determine the structure of the interfacial layer.
This project is funded by Dow Corning (Barry) Ltd
