Comparative Study between <i>Candida antarctica</i> Lipase B and <i>Pseudomonas floroscens</i> as Catalyst for Polycaprolactone Production

Abstract

The Effects of temperature on ring-opening bulk polymerizations of ε-caprolactone was studied by using two different lipases Novozym 435 (immobilized form of lipase B from Candida antarctica), and Pseudomonas Floroscens as biocatalyst. The polymerization of ε-caprolactone was carried out at 50°C, 60°C, 70°C, 80°C, 90°C, and 100°C. For Novozym 435 the results showed that increasing the reaction time of the polymerization system resulted in an increased rate of monomer consumption and hence increased the molecular weight. For an increase in reaction time the conversion increases steadily and after a gradual increase there is a decrease which is found uniform for all the temperature showing a uniform trend. For a temperature of 70°C and 4 hours molecular weight was found to be 8.4 x 104 daltons which were the highest of all the readings that were obtained. In the copolymerizaton of ε-caprolactone (ε-CL) and δ-valerolactone using Pseudomonas fluorescens lipase at 60°C for 20 days a copolymer with molecular weight of 1.97 x 105 was obtained. Effects of the reaction time and temperature on the copolymerization have been examined.