In situ monitoring of enzyme-catalyzed (co)polymerizations by Raman spectroscopy

In situ, fiber optic-based Raman spectroscopy provided real time monitoring of enzyme-catalyzed ring-opening homo- and copolymerizations of ε-caprolactone (ε-CL) and δ-valerolactone (δ-VL). A custom designed reactor equipped with in situ fiber optic probe was used to measure monomer conversion as a function of time. The results from the in situ technique were in good agreement with those determined by offline 1H NMR analysis. Monomer reactivity ratios for the lipase-catalyzed copolymerization of ε-CL and δ-VL were estimated using the Kelen-Tudos method as rε-CL = 0.38 and rδ-VL = 0.29.