Novel and sustainable methods to develop greener polymers
This Thesis reports the development of green approaches towards the synthesis of novel polyesters. Generally, polyesters are synthesised using harsh conditions (such as high temperatures) and rely upon petrochemical-derived building blocks. By using biomass, more specifically plant oil derived sourc...
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| Format: | Thesis |
| Language: | English |
| Published: |
2019
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| Subjects: | |
| Online Access: | http://eprints.nottingham.ac.uk/55748/ https://eprints.nottingham.ac.uk/55748/1/Full%20Thesis%20Mariana%20Gameiro%20Final%20version.pdf |
| Summary: | This Thesis reports the development of green approaches towards the synthesis of novel polyesters. Generally, polyesters are synthesised using harsh conditions (such as high temperatures) and rely upon petrochemical-derived building blocks. By using biomass, more specifically plant oil derived sources, such as glycerol and vernolic acid (fatty acid, FA), we will explore a more renewable approach. In addition, scCO2 will be explored as a novel solvent and processing aid and also, immobilised enzymes will be used as biocatalysts. Chapter 1 has introduced the essential background of green chemistry and the importance of using biomass in the production of polymers. In addition, it also presents the fundamentals of polymer synthesis, with an emphasis on polyesters (linear and branched). A general introduction of enzymes and their use in polymer chemistry is given. Since the main aim of this thesis is to synthesise greener polyesters, the impact of using alternative solvents, such as scCO2, is well described, not only in polymerisations but also in the extraction of valuable compounds from biomass. Chapter 2 provides a detailed description of the high-pressure equipment, the standard operating procedures, analytical techniques and methods used to synthesis and characterise throughout this thesis. Chapter 3 explores the use of glycerol, which is a by-product from biodiesel production, to synthesise linear polyesters through polycondensation with bio-based succinic acid. Bulk polycondensations (120 – 140 ºC), with no catalyst and using stannous octanoate (Sn(Oct)2), as a non-selective metal catalyst produced branched poly(glycerol succinate) (PGLSA). By combining scCO2 and enzyme catalysis (Candida antarctica lipase B, CaLB), it was possible to decrease the temperature of this process to as low as 40 ºC, and produced linear PGLSA. Chapter 4 investigates the synthesis of water soluble glycerol-based surfactants. Using the methodology developed in Chapter 3, PGLSA was used as a main block for the synthesis of potential ... |
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