Formulation of highly electro-conductive thermoplastic composites using PEDOT based fillers with controlled shape factor

Thibault Parpaite
Lecture of Institute guest
29.10.2026 10:00, Lecture room A

The objective of this study is to develop a new conductive thermoplastic material with superior electrical properties. Currently, conductive polymers are filled with carbon or metallic objects. However, these filled thermoplastics displayed drawbacks such as high rigidity, toxicity and high viscosity. An alternative way investigated in this work is to substitute such fillers by intrinsically conductive polymers like Poly(3,4-ethylenedioxythiophene) (PEDOT). In fact, PEDOT can reach stunning electrical conductivities (more than 1000 S/cm) when combined with polymeric dopant like poly(styrene sulfonate) and is frequently used (thin film or gels) in areas such as medical and energy’s sectors. However, incorporation of PEDOT in the classical hot melt processes of plastic industry is still challenging. In a previous work we performed the synthesis of electro-conductive PEDOT particles in order to incorporate it into polyethylene oxide matrix by extrusion process. Composites with interesting conductivities up to 12 S.cm-1 were obtained but a high amount of PEDOT fillers was necessary to reach the electrical percolation threshold. To reduce this percolation threshold, a new approach based on supported polymerization process is investigated in this work. Our goal is to control the shape factor of the synthetized conductive PEDOT particles by using different fillers like silica, graphene or clays for the PEDOT polymerization. The objective is to coat these different fillers with a conductive shell of PEDOT and then study the impact of the different shape factor on the electrical percolation threshold of the associated composites. Relationships between process, morphology and properties were analyzed using SEM, X-Ray tomography and four probe resistivity measurements. Percolation curves for different shape factor were also achieved and compared to the initial one obtained with micrometric PEDOT particles.

The lecture is presented in English