Synthesis of polycaprolactone via ring opening polymerization catalyzed by Candida antarctica lipase B immobilized onto an amorphous silica support

In this work, an amorphous silica material was used as a support to immobilize Candida antarctica lipase B (CALB) by physical adsorption method, and e-caprolactone (ϵ-CL), 7-membered lactone, was polymerized via ring opening polymerization catalyzed by immobilized CALB (IML). The optimum temperature, enzyme concentration and time period were investigated for poly(ecaprolactone) (PCL) synthesis. Molecular weights of PCLs were determined by using gel permeation chromatography (GPC) and proton nuclear magnetic resonance (¹H-NMR) analysis. The surface morphologies of PCLs were analyzed by scanning electron microscopy (SEM). Besides, PCLs were successfully characterized by fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. The results showed that high molecular weights and monomer conversions of PCLs were achieved about 14300 g/mol and 90 %, respectively. This study demonstrated immobilization of lipase improves properties of free lipase and enzymatic polymerization of ϵ-CL is an effective method contributed ecofriendly polymer processes.