, , , Richard Gross
The enzyme Candida antarctica Lipase B (CAL B), immobilized on a crosslinked poly(methyl methacrylate) (PMMA) support, catalyzes the ring-opening polymerization of ε-caprolactone to make biodegradable polyesters. Weak hydrophobic interactions of CAL B physisorbed on the PMMA surface can permit catalyst leaching, decreasing the concentration of remaining enzymes for polymerization and contaminating the polycaprolactone (PCL) product. Recycling of the solid-supported polymerization catalyst is necessary for commercialization; this requires a thorough understanding of catalyst activity, stability and surface interactions under varied reaction conditions. A quartz crystal microbalance (QCM) was used to monitor in situ adsorption at the solid-support/enzyme interface, while deconvoluting background events, such as polymer swelling or non-specific binding. A crosslinked PMMA thin film (50nm) on a QCM crystal was fabricated to mimic the hydrophobic surface of the catalyst bead. Enzyme stability and PCL binding to the CAL B surface was monitored as water content of the reaction incrementally increased.
The 6th ACS Symposium on Green Polymer Chemistry: Polymer Biocatalysis and Biobased Materials
August 18-23, 2012
The 244th Meeting of the American Chemical Society
enzyme catalysis, ring-opening polymerization, green chemistry, surface chemistry