Studies leading to the large scale synthesis of polyesters using enzymes

The ability of immobilised Candida antarctica lipase to catalyse the condensation of diols and diacids was studied. The range of acids investigated (in condensations with butane-1,4-diol) included adipic, maleic, fumaric, itaconic, (E)-hex-3-enedioic and acetylenedicarboxylic acids, while the diols studied, in condensations with adipic acid, encompassed ethane-, propane-, butane-, pentane- and hexane-diols as well as (Z)-but-2-ene-1,4-diol and but-2-yne-1,4-diol. The oligomerization of hexane-1,6-diol and adipic acid was most facile and was chosen for scale-up. A mechanism for the polycondensation process is proposed.