Effect of processing conditions on the properties of vitrimerized polybutylene terephthalate prepared by reactive extrusion

Effet des conditions de traitement sur les propriétés du polybutylène téréphtalate vitrifié préparé par extrusion réactive

Quentin-Arthur Aimé Q.-A. Poutrel POUTREL (1) , R. Kmo (2) , A. Cohadon (1) , Julien Boisse (2) , S. Rouzière (3) , Stéphane André (2) , Sandrine Hoppe (1) , Laurent Farge (2)

1 LRGP - Laboratoire Réactions et Génie des Procédés
2 LEMTA - Laboratoire Energies et Mécanique Théorique et Appliquée
3 LPS - Laboratoire de Physique des Solides

This study examined the effects of continuous reactive extrusion on the properties of vitrimerized thermoplastics derived from polybutylene terephthalate (PBT). PBT formulations were prepared using epoxy (crosslinker) and zinc acetylacetonate (transesterification catalyst) to form dynamic covalent networks. Reactive extrusion was performed at different screw rotation speeds (50, 100, 200 rpm) with controlled residence times to compare the effects of the shear stress during the formation of crosslinks on the vitrimer properties. The rheological behavior of the extruded vitrimerized PBT suggests that competition between chain scission and branching occurs during the dynamic crosslinking of thermoplastics. Increasing the shear stress and/or time in the extruder was found to favor chain scission over crosslinking which makes gelation unattainable. In the case of injection molded specimens, tensile and X-ray diffraction tests of vitrimerized PBT extruded at different shear stress indicated a significant relationship between the degree of crosslinking, the orientation of crystallites, and the ability of the polymer network to withstand deformation at elevated temperatures.

Mots clés: Vitrimer; continuous reactive extrusion; epoxy; process engineering

Domaines: Polymères; Génie des procédés

Quentin-Arthur Aimé Q.-A. Poutrel POUTREL, R. Kmo, A. Cohadon, Julien Boisse, S. Rouzière, et al.. Effect of processing conditions on the properties of vitrimerized polybutylene terephthalate prepared by reactive extrusion. Polymer Degradation and Stability, 2024, 225, pp.110820. ⟨10.1016/j.polymdegradstab.2024.110820⟩. ⟨hal-04579451⟩