Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286220
Title: The use of enzymes in organic solvents in polytransesterification reactions
Author: Wiggett, Adrian J.
ISNI:       0000 0001 3567 9314
Awarding Body: Aston University
Current Institution: Aston University
Date of Award: 1998
Availability of Full Text:
Access through EThOS:
Access through Institution:
Abstract:
The aim of this research project was to identify the factors affecting the porcine pancreatic lipase (PPL.)-catalysed polytransesterification of a diester and a diol in organic solvents. It was hoped that by modifying reaction conditions a commercially acceptable polymer molecular weight (Mn) of 20,000 daltons might be attained. Exploratory investigations were carried out using 1,4-butanediolibis(2,2,2- trichloroethyl) adipate and glutarate systems in diethyl ether, with and without molecular sieves. It was found that molecular sieves promoted the reaction by reducing hydrolysis of the ester end-groups, resulting in polymer molecular weights between 1.2 and 2.2 times greater than those obtainable without molecular sieves. Investigations were then concentrated on the PPL-catalysed polytransesterification of 1,4-butanediol with divinyl adipate. The particular advantage of this system is that the reaction is irreversible. The effects of varying substrate concentration, mass of drying agent, reaction solvent, reaction temperature, mass of enzyme and also enzyme immobilisation on the 1,4-butanediolidivinyl adipate system were investigated. The highest molecular weight polymer obtained for the PPL-catalysed polytransesterification of 1,4-butanedial with divinyl adipate in diethyl ether was Mn -8,000. In higher boiling ether solvents molecular weights as high as Mn -9,200 were obtained for this system at elevated temperatures. It was found that the major factor limiting polymerisation was the low solubility of the polymer in the solvent which resulted in precipitation of the polymer onto the surface of the enzyme.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.286220  DOI: Not available
Keywords: Chemical Engineering ; Applied Chemistry ; Chemical Engineering Chemistry, Organic Chemical engineering
Share: