High-Performance Immobilized Lipase Catalyst for Polyester Synthesis

Abstract

KEY WORDSEnzymatic Polymerization / Immobilized Lipase / Polyester / Lactone / Lipase is an enzyme that catalyzes hydrolysis of fats (fatty acid triglycerides) in living cells. In a nonaqueous medium, on the other hand, lipase can act as catalyst for esterification and transesterification. 1 This characteristic property has been applied to lipasecatalyzed ring-opening polymerization and polycondensation under mild reaction conditions to biodegradable polyesters and polycarbonates. 2-9 Enantio-and regioselective polymerizations have been achieved via lipase catalysis to give functional polyesters, most of which can not be synthesized by conventional chemical catalysts. [10][11][12][13][14][15] Candida antarctica lipase (lipase CA) immobilized on macroporous acrylic resin (Novozym 435) is industrially developed for modification of triglyceride oils. Previously, we first demonstrated highly efficient catalysis of Novozym 435 for polymerization of lactones; 16 a small amount of this enzyme (less than 1%) induced the polymerization of ε-caprolactone (ε-CL) and the polymerization rate using Novozym 435 was much larger than that by other commercially available lipases under the similar reaction conditions. Furthermore, Novozym 435 could be repeatedly used for the polymerization of ε-CL. 17 In the range of 5 cycles, the polymerization results hardly changed.Activity of immobilized enzyme catalysts is well known to depend on their support properties such as hydrophilicity and porosity. 18 In this study, we have screened the enzyme support for development of the immobilized lipase catalyst for efficient production of polyesters. 19 RESULTS AND DISCUSSIONIn this study, four polymeric and one ceramic supports have been employed (Table I). All the supports are powdery in the diameter larger than 100 µm and have porous structures. There were no functional groups † To whom correspondence should be addressed. Scheme 1.in the polymer supports (sample A-D) and the phenyl group was introduced on the surface of the pore in the ceramic support (sample E). The immobilization was carried out by mixing an aqueous solution of lipase CA and the support in a phosphate buffer of pH 7.0. The amount of protein fixed onto the support was calculated from the difference of protein content in the solution before and after the immobilization (Table II). The immobilized protein content scarcely depended on the support type except sample C, suggesting that a support with small poresize is not suitable for the immobilization of lipase CA. For reference, the amount of the immobilized protein of Novozym 435 was 175 mg g −1 support (data from supplier).In order to examine the catalytic activity of the present immobilized lipases for the polyester synthesis, the polymerization of ε-CL was performed in toluene at 60 • C for 1 h (Scheme 1). The lipase immobilized on polypropylene (sample B) showed the highest activity. An immobilized lipase on porous polypropylene was reported to catalyze ester hydrolysis and esterification. [20][21][22] Samples D and E ...

Enzymatic Synthesis of Polyesters via Ring-Opening Polymerization

“…The surfactant-coated lipase efficiently catalyzed the ring-opening polymerization of lactones in organic solvents in which the modified enzyme was soluble [85,86]. The Candida antarctica lipase immobilized on porous polypropylene more efficiently catalyzed the ring-opening polymerization of PDL as well as the polycondensation than lipase CA (Candida antarctica lipase immobilized on acrylic resin) [87].…”

Lipase‐Catalyzed Synthesis of Furan‐Based Oligoesters and their Self‐Assembly‐Assisted Polymerization

“…[40][41][42] Althoughaw ide range of enzyme catalysts is available for the synthesis of macromolecules, Candidaa ntarctica lipase B( CALB) possesses many desirable advantages, whichi nclude compatibilityw ith a magnitude of substrates and solvents andr egio-a nd enantioselectivities. [45,46] Recently,K obayashi and co-workersd iscussed briefly the production of value-added functional macromolecules by an environmentally friendly enzyme catalysis method. [45,46] Recently,K obayashi and co-workersd iscussed briefly the production of value-added functional macromolecules by an environmentally friendly enzyme catalysis method.…”

Synthesis, characterization, and mechanical performance of various functionalized carbon nanotubes‐polyurethanes nanocomposites

“…In our laboratory, we have developed a method to obtain PCL‐diol by an enzyme‐catalyzed polymerization, using Yarrowia lipolytica lipase (YLL) immobilized in a hydrophobic acrylic resin as catalyst. Using this approach, polymerization conditions are well controlled at a reduced cost …”

“…Using this approach, polymerization conditions are well controlled at a reduced cost. [7][8][9][10] PUs have been used as polymeric matrices for the different types of nanocomposites known. Based on their chemical composition, the nature of the interactions between nanofiller and PU-specific domains [hard (HS) or soft (SS)] can vary from one system to another.…”