Improving Rheological behavior of Functional Thermoplastic Elastomers for Material Extrusion Additive Manufacturing – RHEBEL

Material Extrusion Additive Manufacturing (MEX) is a popular and widely used technique that offers significant promise in design and industrial potential. However, only a limited number of materials are available, which is a limitation in terms of accessible properties and applications. Indeed, thermoplastic elastomer (TPE) materials have encountered many difficulties being adapted to MEX regarding their melting behavior, flowability, maintaining the given shape upon cooling, layer adhesion, and anisotropic shrinkage. Consequently, functional TPE innovative formulations and a fundamental understanding of their processability are needed.
RHEBEL objective will be to control TPE processing characteristics, material properties, and functionality. With this view, formulations of TPE will be developed to improve the behavior at all stages to target low viscosities while conferring a yield stress flow behavior either by dispersing fillers in a controlled manner or by creating physico-chemical interactions between macromolecular chains, potentially through reversible reactions. Printability would be evaluated by the achievable resolution, the holding of thin vertical walls, the possibility of manufacturing overhangs, and productivity.
The project will be coordinated by IMP, bringing experience in TPE formulation, chemical modification of polymers, fillers dispersion, rheological behavior tuning, and crystallization characterization. LIST competencies in advance characterization and additive manufacturing, including 4D printing, will complement IMP’s expertise. In addition, LIST will use an instrumented pellet MEX machine that increases the range of materials that can be processed by skipping the filament fabrication step. Hence, RHEBEL will contribute to fundamental knowledge in functional TPE development, from their modification, formulation, MEX printing to their testing.