Lipase B from Candida antartica : applications to industrial polyester synthesis. ...

• Main Author: Harffey, Paul.
• Format: Thesis
• Language: unknown
• Published: University of Liverpool Repository 2023
• Subjects: Antarc*; Antarctica; antartic*
• Online Access: https://dx.doi.org/10.17638/03175458; https://livrepository.liverpool.ac.uk/id/eprint/3175458

In the early 1990s, enzymatic polymerization studies on an unactivated adipic acid (A) / butane-1,4-diol (B) system in anhydrous organic media suggested that in solvent-free conditions a step-growth mechanism operates involving the effective sequential addition of an 'AB' unit. Subsequent optimisation work led to development of an efficient solvent-free process using lipase B from Candida antarctica as catalyst at temperatures of around 60°C, producing polyesters with unique properties compared to their counterparts synthesised using conventional high temperature processes. The present work describes the synthesis and unambiguous characterisation by GPC of a series of key oligomers formed during the enzymatic process, enabling a clearer understanding of the polymer assembly route. Use of semi-quantitative methods to compare the reactivity of these oligomeric species along the proposed enzymatic reaction pathway further clarifies the polymerisation mechanism and explains the differences between the final ...