Cyclic derivatives of D-glucose and tartaric acid as building blocks for renewable polyesters

• Autores: Cristina Japu
• Directores de la Tesis: Sebastián Muñoz Guerra (dir. tes.), Antxon Martínez de Ilarduya Sáez Asteasu (dir. tes.)
• Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2014
• Idioma: inglés
• Tribunal Calificador de la Tesis: Virginia Cádiz Deleito (presid.), Marta Bermúdez Hermida (secret.), Katja Loos (voc.), Tzanko Tzankov (voc.), José Alberto Méndez González (voc.)
• Materias:
  • Química
    • Química macromolecular
      • Macromoléculas
      • Poliésteres
    • Química orgánica
      • Química de los hidratos de carbono
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • Three series of aromatic copolyesters derived from poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT) and poly(hexamethylene terephthalate) (PHT) have been synthesized by melt polycondensation in which the terephthalate and oxyalkylene units have been partially or totally replaced by monocyclic and bicyclic diacids and diols obtained by derivatization of renewable monomers such as tartaric acid and D-glucose respectively. Another series of aliphatic copolyesters derived from poly(butylene sebacate) has been prepared by both melt polycondensation and enzymatic polymerization in solution where both the sebacate and butylene units have been partially or totally replaced by the bicyclic diacid or diol derived from D-glucose. All series of polyesters and copolyesters were characterized by FTIR and NMR in solution. The chemical composition of the copolyesters was determined by 1H NMR. On the other hand the microstructure, determined by 13C NMR was observed to be at random for all series. The molecular weights determined by intrinsic viscosimetry and gel permeation chromatography (GPC) were high but decreasing when the content of the sugar monomer increased. The thermal properties were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis. It was observed that the thermal stability was not affected when the oxyalkylene unit was the replaced unit, but decreased slightly when the terephthalate unit was replaced one. The new copolyesters showed higher glass transition temperatures than the parent poly(alkylen terephthalate)s, being superiors for the copolyesters obtained from the bicyclic derivative of D-glucose than for the monocyclic derivative of tartaric acid. All copolyesters were less crystalline than the parent homopolyesters, with both melting and enthalpies decreasing with the increased content of the sugar units. The crystalline structure determined by X-ray diffraction was similar to the PET, PBT and PHT polyesters. Finally it was studied the hydrolytic and enzymatic degradability by weight loss, molecular weight determinations and scanning electron microscopy (SEM). All new copolyesters showed enhanced degradability in water and biodegradability.