The purpose of this theme is to explore the capabilities of the extrusion process to produce innovative materials. Owing to its outstanding mixing capacities, extrusion is far more than a shaping process. It is able to mix highly viscous media, blends of solids and liquids, or of liquids with very large viscosity ratio, with controlled dispersive and distributive effects. The tunability, brought by the modularity of twin screw extruders or co-kneaders, makes it a valuable continuous reactor to carry various chemical reactions as well as blend structuration. Other side chemical engineering operations such as devolatilization and purification can also be considered in cooperation with other themes of the Lyon Polymer Science and Engineering consortium.
Among the chemical reactions of interest, heterogenous phase reaction, in situ sol-gel process, foaming, compatibilization, grafting of crosslinkers that do not require chemical initiators, are the most promissing. In the field of complex mixing, co-continous blend morphologies, large viscosity ratio, selective location of nano-fillers at interface, highly filled or highly interacting materials, structuration under flow, multiscale structuring and use of supercritical CO2 as solvent, carrier, processing aid, plasticizer, foaming agents or cleaning media can be mentioned as prospective field of research and applications.
Though the litterature is already abundant in this area, deeper studies on the control of thermal effects, orientation in flow fields, microrheology, mechanisms of structuration, dispersive and distributive mixing for liquids or fillers are some fundamental aspects that are still relevant and worth studying for complex systems. The large panel of polymers, fillers and additives make it a large field of innovative research for the LPSE. This approach is especially strenghtened by societal demand in view of cleaner process, eco-friendly materials and re-use or regeneration of plastics materials.