Certaines applications (notamment dans l'aéronautique) demandent des polymères thermostables semi-cristallins avec des résistances et des températures de fonctionnement de plus en plus élevées (Tg supérieures à 170°C) tout en conservant de bonnes propriétés de mise en œuvre (Tf ne dépassant pas 350°C) aptes aux procédés industriels. Ce projet de thèse porte sur la synthèse et la caractérisation de nouveaux polymères hautes performances de type poly(aryl éther cétone amide)s à partir d'un monomère de type EKKE aux extrémités acide carboxylique. Ainsi, trois voies de synthèse des amides par condensation ont été étudiées : entre les acides carboxyliques et les isocyanates, entre les chlorures d'acyle et les amines, et entre les acides carboxyliques et les amines par phosphorylation. La comparaison des propriétés thermiques et leurs corrélations avec les structures chimiques des poly(aryl éther cétone amide)s aromatiques et semi-aromatiques obtenus sont particulièrement détaillées. / Some demanding applications (especially in aerospace) require more and more semi-crystalline thermostable polymers with high temperature resistance and durability (Tg above 170 °C) while maintaining good processing properties (Tm not exceeding 350°C) suitable for industrial manufacturing.This work deals with the synthesis and characterization of new high performance poly(aryl ether ketone amide)s polymers from an EKKE monomer with carboxylic acid extremities. Thus, three amide condensation synthetic routes were studied: between carboxylic acids and isocyanates, between acyl chlorides and amines, and between carboxylic acids and amines by phosphorylation. The thermal properties and their correlation with the chemical structures of the obtained aromatic and semi-aromatic poly(aryl ether ketone amide)s are compared and especially detailed.

Membrane technology has great potential to complement traditional energy-intensive molecular separation processes such as distillation, with the advantage of low footprint generation. However, this would only be achieved with the development of better membranes able to operate in challenging conditions, including combinations of organic solvents, high temperatures, extreme pHs, and oxidative environments. This dissertation aims to use high-performance polymeric materials that can withstand temperatures of 120 °C in polar aprotic solvents like N,N-dimethylformamide as separation membranes, using different crosslinking strategies and alternative routes for commercially available material processing. The thesis will be divided into two main approaches. The first approach will start from soluble polyimides as precursors, with designed functionalities that allow post-membrane modifications, such as chemical crosslinking, thermal crosslinking, and thermal rearrangement to enhance the material's chemical resistance. The focus will be on the polyimide synthesis by an alternative one-step room-temperature polyhydroxyalkylation reaction. The chemical and thermal crosslinking take place without involving the imide bond, by incorporating a highly tunable functional group (isatin) in the synthesis of the materials. Propargyl as a pendant group will be used for the thermal crosslinking, and hydroxyl group for the thermal rearrangement. In all cases, the obtained membranes were stable in common organic solvents at 120 °C. The second approach will start from intrinsically solvent-resistant and commercially available poly(aryl ether ketone)s, turned into membranes by a closed-loop modification-regeneration strategy, to address long-term separations in organic solvents at high temperatures. We present for the first time porous poly(aryl ether ketone) flat-sheet and hollow fiber membranes prepared without the use of strong acids or high temperatures. Two methodologies are proposed. The developed strategies shall contribute toward avoiding the regular consumption of new materials and waste generation since the polymer used does not require crosslinking for its stability under organic solvents.

Six poly(ether ketone ketone)/carbon composite panels were manufactured from powder coated towpreg. All six panels were initially processed using a hot press equipped with controlled cooling. Four of the panels were used to investigate the effect of cooling rate on crystallinity. A fifth panel was used to investigate the effect of annealing the composite after completion of the standard fabrication process. The sixth panel was used to investigate changes in toughness due to manufacturing towpreg with polymer that had been reclaimed from the towpreg fabrication system’s air cleaner. Cooling rates of 2°C/min, 4°C/min, 6°C/min, and 8°C/min resulted in composites with crystallinities of 33%, 27%, 24%, and 23%, respectively. The principal investigation of the effect of cooling rate on crystallinity and mode I and mode II strain energy release rates, G_Ic and G_IIc, respectively, showed that G_Ic and G_IIc values increase with increasing cooling rate. Comparison of the toughness values as a function of crystallinity showed that the dependence of toughness on crystallinity is approximately equivalent to the dependence of toughness on cooling rate. Comparison of the data from the annealed panel to that from the analogous principal panel showed that annealing increased the crystallinity and decreased the mode I strain energy release rate. There was no effect, however, on the mode II strain energy release rate. Comparison of the data from the panel made with reclaimed polymer to that from its analogous principal panel showed that the reclaimed polymer panel had equivalent crystallinity and G_Ic values. On the other hand, the G_IIc values in this panel were lower than in the analogous principal panel. / Master of Science