Ionic lipase-catalyzed polymerization

Fujita MY, Saito C, Takeoka Y et al (2008) Lipase-catalyzed polymerization of L-lactide in ionic liquids. Polym Adv Technol 19 1396-1400... 

Lipase-catalyzed Polymerization in Ionic Liquids 337 13.3 Enzymatic Polymerization under Biphasic Conditions 339... 

Room-temperature ionic liquids have received much attention as green designer solvents. We first demonstrated that ionic liquids acted as good medium for lipase-catalyzed production of polyesters. The polycondensation of diethyl adipate and 1,4-butanediol using lipase CA as catalyst efficiently proceeded in l-butyl-3-methylimidazolinium tetrafluoroborate or hexafluorophosphate under reduced pressure. The polymerization of diethyl sebacate and 1,4-butanediol in l-butyl-3-methylimidazolinium hexafluorophosphate took place even at room temperature in the presence of lipase BC. ... 

Lipase-catalyzed transesterification to prepare polyesters (replacing the traditional chemical polymerization at >200 °C) has received considerable attention in recent years. CaLB was found to mediate polyester synthesis in the ionic liquids [BMIm][BF4], [BMIm][PF6], and [BMIm][ Tf2N] at 60°C [110, 111, 112], but the molecular weight of the product was rather low compared with that in a solventless system [113], perhaps owing to the high viscosity of ionic liquid media. 

Ionic liquids are often used as reaction solvent for the synthesis and modification of polymers due to their green character [76]. The first paper on ionic liquids as solvent for enzymatic polymerization appeared in 2002. Lipase-catalyzed ROP of e-CL and the polycondensation between diethyl adipate or sebacate and 1,4-butane diol were achieved in an ionic liquid such as l-butyl-3-methyl-imidazolium salts ([bmim] [PFs]). The ROP gave rise to PCL with of4,200 MJMn = 2.7) in 97% yields at 60°C after 7 days [77]. Lipase CA-catalyzed ROP of e-CL in three ionic liquids, [bmimliBFJ, [bmim][PF6], and [bmim][(CF3S02)2N], at 60°C for 24 h produced PCL with a higher of 7,000-9,500 2.4) in good yields. In... 

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