Poly(glycerol sebacate) (PGS): a base for new materials

• Main Author: Godinho, Bruno Miguel Marques
• Other Authors: Ferreira, Artur Jorge de Faria
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2024
• Subjects: Poly(glycerol sebacate) (PGS); Poly(glycerol succinate) (PGSu); Poly(glycerol sebacate-co-succinate) (PGSSu); PGS-based materials; Polycondensation; Enzymatic synthesis; Crude glycerol; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10773/41289

Dear reader, the thesis presented here under the title: "Poly(glycerol sebacate) (PGS): a basis for new materials" consists of four chapters. Chapter 1 presents a literature review that brings together more than 20 years of knowledge about PGS, including somewhat forgotten publications from the 1990s, where the term "PGS" was not used. In this chapter, the reader learns about the different methodologies for synthesizing PGS, their problems, properties and degradation processes, as well as the new materials that have emerged based on PGS, and their applications. Chapter 2 describes the catalyzed synthesis of PGS prepolymers, using two commercial forms of Lipase B enzyme from Candida antarctica (free and immobilized) and using two types of glycerol (crude glycerol, a by-product of biodiesel production, and high purity glycerol). The results presented are the outcome of analyses carried out on the four pre-polymers synthesized, based on analytical techniques such as NMR, titrations, and mass spectrometry (MALDI-ToF-MS). The reader will learn, among other things, that lipase B did not suffer any inhibition despite the use of crude glycerol and kept all its characteristics, such as regioselectivity for the synthesis of linear polymeric structures and the ability to carry out synthesis at low temperature (60 oC). Chapters 3 and 4 introduce the reader to the synthesis of poly(glycerol-co-diacids) based on a mixture of diacids, such as sebacic acid, used in the synthesis of PGS, and succinic acid, used in the synthesis of poly(glycerol succinate) (PGSu). The work involved the synthesis of seven polymers at 150 oC, up to 55% degree of esterification with different molar ratios of these acids, including PGS, PGSu and five corresponding mixtures of poly(glycerol sebacate-co-succinate) (PGSSu). Chapter 3 presents the results of a detailed comparative analysis of the polymer composition of all the prepolymers synthesized, using mass spectrometry (ESI-MS) and NMR. Among the various observations, the reader will be made aware ...