Association of microwave technology to reactive polymer systems without solvent in the molten state – MOMix

MOMix is a multidisciplinary project involving specialized laboratories and firms in thermal modelling, microwaves, processing and polymer chemistry. The project ambition a technological breakdown in the field of reactive processing implementing polymers in the molten state and under high shears.

The double objective, forward, is to integrate the microwave technology in processes as a source of fast heating without inertia from the solid state up to the molten state and as an effective activator of chemical reactions in a corotating twin screw extruder, a continuous process widely in favor of sustainable development. MOMix project proposes to raise this subject by investigating associated scientific problematics, never studied, by 2 - 4 TRL.

Fundamental studies will allow to understand the interactions wave-material in the solid state to model thermal kinetics to melt polymers. The study of the polymer-wave interactions will be spread to molten polymers coupled with chemical reactions under high shear, to quantify the effect on the acceleration of the reactions in these particular conditions.

By means of digital tools dedicated to microwaves, supported by the established thermal models and a 3D numerical simulation software of the process adapted specifically, the realization of a first demonstrator will be made: a 70 cm3 specific tank of an existing internal mixer equipped with two rotors.
Serving first as a tool to experimentally validate thermal models first established before serving for the elaboration of new and experimental biosourced polymer materials, without solvent and in the molten state, by taking advantage of strong kinetic accelerations thanks to the selectivity of the microwaves being able to warming specifically a catalyst or reactive functions.

The idea to combine microwave energy and high shear is to take advantage of the efficiency of blending to dissipate heterogeneous temperatures which are often present in the case of the application of microwaves. It will also allow to accelerate strongly reaction times in processes like extrusion where the chemistry remains little used because of too short residence times to perform a chemical reaction until its term. The expected complementarity between process and beam would be thus bilateral in the case of a continuous process.

The project plans to also approach fundamental questions around the rheology because there is till now, no study which can describe the rheological behavior of polymers or polymer systems in the molten state under the influence of an electromagnetic field in the microwave frequencies. A modification of the rheological behavior would require the determination of new laws allowing later, the correct simulation of the process

The exploration of this new disciplinary fields in the high potential of outlets will require the conception of specific equipments to make essential dielectric (epsilon ' and epsilon " according to T), thermal and rheology measurements as well as the elaboration of an innovative fluxmeter for online measurements of temperature and heat flow.

MOMix project will inevitably lead to in a downstream project by 5 – 7 TRL, already envisaged, to transpose the obtained results towards industrializable processes in break to produce innovative materials thanks to the combined effects by selective heating and reactivity that only the microwaves can allow it. The applications concern any polar or partially polar system as natural polymer materials (polysaccharides, proteins, lignocellulosics), ionic systems, or materials with fillers where the microwave chemistry shows a very strong development since the beginning of 2000's.