Novel poly(ethylene isophthalate) (PEI) and poly(ethylene terephthalate) (PET) polymers containing terminal units derived from sodio 3-sulfobenzoic acid (SSBA) were synthesized using catalyzed melt polymerization techniques. Various concentrations of the ionic end group, SSBA, were successfully incorporated in a telechelic fashion. For comparison, polyesters containing telechelic alkyl groups with controllable molecular weights were also synthesized. Furthermore, ionic copolymers of dimethyl isophthalate and trans-cyclohexane dicarboxylate, dimethyl isophthalate and dimethyl terephthalate were synthesized to study the influences of polarity and rigidity of the polymer chain backbone on material properties. Novel branched polyester ionomers using trimellitic anhydride were also prepared. In addition to modifying the polymer compositions, PET ionomers were blended with zinc stearate to investigate the effect of plasticizer on the melt processibilty of the ionomers. FTIR spectroscopy, which was used to quantify the sulfonate end groups for all of the ionomers, indicated an absorbance peak for the S-O stretching mode between 600-700 cm⁻¹. ¹H NMR spectroscopy was used to confirm the structure of the ionic and non-ionic polyesters, as well as to verify the presence of the terminal groups. By systematically varying the chemical structure of these ionomer model systems (i.e., altering the contents of ionic functional groups), detailed characterizations were carried out, wherein the ionic interactions/aggregations in the ionomers were found to play an important role in the resulting material properties. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements were performed to study the effects of ionic groups and oligomer composition on the thermal properties of the polyesters. The glass transition temperatures of the ionomers revealed that the ionic interaction helped to maintain the structural integrity of the polymer chains, thus limiting their mobility. The dilute solution viscosity behavior of the ionomers exhibited upward curvature, which is a key characteristic of an ionomer. In PEI ionomers, the ionic aggregates formed at lower temperatures (<150 °C), while at higher temperatures (>150 °C), the ionic aggregations dissociated and behaved similarly to oligomers with lower molecular weights. Dodecanol was used as an effective end-capper to control the molecular weight of the non-ionic polyesters. In addition to telechelic ionic PEI and PET homopolymers, copolymers of poly(ethylene isophthalate-co-trans-1,4-cyclohexane dicarboxylate) (PEI-co-trans-CHDC) and poly(ethylene isophthalate-co-terephthalate) (PEIT) telechelic ionomers were also synthesized and characterized. Introducing trans-1,4-cyclohexane dicarboxylate into PEI ionomers decreased the polarity and packing regularity of the polymer chains. Also, the kinked-structure of dimethyl isophthalate reduced the regularity of the polymer chains in PET ionomers, thus reducing their propensity for rapid crystallization. Crystallization kinetics were studied for both ionic and alkyl telechelic polyesters, and resulting data revealed that the nature of the endgroup had a dramatic effect on crystallization from the melt state. The catalyst residue in the polymers also affected the crystallization rate for both ionic and non-ionic polyesters. With regard to the ionomers, antimony catalyst interacted with ionic aggregates, further increasing the crystallization rate. Branched PEI and PET ionomers showed an increase in melt strength. After blending with zinc stearate, the melt viscosity of the PET ionomers dropped dramatically. / Master of Science

Le poly(butylène succinate) (PBS) est un polyester aliphatique biodégradable dont les propriétés en font un bon candidat pour le remplacement des polyoléfines. De plus, ses deux monomères, l'acide succinique et le butane-1,4-diol, peuvent être issus de la biomasse via un procédé de fermentation de sucres. L'étude réalisée ici a été séparée en deux grandes parties : le PBS linéaire d'une part et le PBS branché d'autre part. La première partie montre que la cinétique de synthèse du PBS suit bien le modèle d'estérification établi par Flory. Par la suite, l'étude des propriétés physico-chimiques du PBS a permis de remonter à des paramètres comme la masse molaire critique d'enchevêtrement, le module du plateau caoutchoutique, l'énergie d'activation du PBS fondu ou encore les paramètres de l'équation Mark-Houwink-Sakurada. Une étude sur ses propriétés thermiques a permis de décrire l'évolution de son comportement en fonction de sa masse molaire. Enfin, le profil d'énergie potentielle de l'estérification entre l'acide succinique et le butane-1,4-diol a été tracé en utilisant un outil de chimie quantique. La seconde partie traite de l'étude de PBS branchés obtenus en employant des agents de branchement (polyols) pouvant être issus de la biomasse comme l'huile de ricin, le glycérol et le polyglycérol. La stratégie adoptée a été le couplage entre un oligomère PBS fonctionnalisé acide carboxylique et les agents de branchement. L'étude en présence d'huile de ricin a mis en avant les relations entre la structure, déterminée en SEC-Triple Détection, et les propriétés physico-chimiques du PBS branché. L'optimisation de la synthèse en présence de glycérol ou de polyglycérol a été abordée à partir de la méthode des plans d'expériences. Comparé à la méthode « un facteur à la fois », des résultats prometteurs et semblables à ce qui est rapporté dans la littérature ont été obtenus pour l'étude du PBS branché en présence de glycérol. / Poly(butylene succinate) (PBS) is a biodegradable aliphatic polyester whose properties make it a promising polymer for the replacement of polyolefins. Moreover, its two monomers, succinic acid and 1,4-butanediol, can be produced via a fermentation process of sugars. This study has been separated into two great parts: linear PBS on the one hand and branched PBS on the other hand. In the first part, kinetics of the PBS synthesis showed a good agreement with the esterification model of Flory. We determined some fundamental parameters of PBS like critical molecular weight of entanglement, the rubbery plateau modulus, the energy of activation of melt PBS and parameters of the Mark-Houwink-Sakurada relationship. We have also realized a study on the influence of the molecular weight on the thermal properties of PBS. Finally, we constructed the potential energy profile of the esterification between succinic acid and 1,4-butanediol through a quantum chemistry study. The second part dealt with the study of branched PBS in the presence of biosourced polyols like castor oil, glycerol and polyglycerol. These syntheses were realized between an acid-functionalized PBS oligomer and the branching agents. We put forward the relationships between the structure, determined by SEC-Triple Detection, and the physicochemical properties of branched PBS in presence of castor oil. Syntheses of branched PBS in presence of glycerol or polyglycerol were optimized with design of experiments technique. Promising and similar results from the literature were obtained in the case of branched PBS in presence of glycerol compared to the method of “one parameter at a time”.