Lipase-catalyzed synthesis poly esters

Hayes, D.G. Lipase-catalyzed synthesis of poly-hydric alcohol-poly(ricinoleic acid) ester star polymers. Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.) 2005, 46 (1), 276-277. 

Jiang, Y., Liu, C., and Gross, R.A. (2008) Lipase-catalyzed synthesis of aliphatic poly(carbonate-co-esters). Macromolecules, 41 (13), 4671-4680. 

The fatty esters of polyethers are known to be good surfactants, and many commercial products are available in the market place. Most people use chemical methods to achieve the required synthesis. Enzymatic methods can also be used however, the reaction needs to be optimized. An example is the lipase-catalyzed synthesis of fatty acid diester of poly(ethylene glycol) EG). 

Lipase-Catalyzed Synthesis of Poly(Hydroxy Acid) Esters... 

Feng Y, Klee D, Keul H, Hdcker H (2000) Lipase-catalyzed ring-opening polymerization of morpholine-2,5-dione derivatives a novel route to the synthesis of poly(ester amide)s. Macromol Chem Phys 201 2670-2675... 

Ester synthesis of fatty acid ethyl ester. The lipase-catalyzed esterification of fatty acid and alcohol is well-known. It was also favorable for the esterification of poly unsaturated fatty acids under mild conditions with the enzyme. However, the activity of native lipase is lower in polar organic solvents, i.e. ethanol and methanol. The synthesis of Ae fatty acid ethyl ester was carried out in ethanol using the palmitic acid-modified lipase. As shown in Figure 7, the reactivity of the modified lipase in this system was much higher than that of the unmoditied lipase. 

The synthesis of chiral poly(depsipeptides), polymers with alternating amide and ester bonds, by lipase-catalyzed ring opening of 3-isopropyl morpholino-2,5-dione (19) was shown by Hocker and coworkers (Scheme 11.5) [26], Various lipases were tested for the bulk polymerization of these heterocyclic monomers at temperatures of 100 °C or above. PPL and lipase type III from a pseudomonas species were shown to be effective catalysts. The isolated polymers showed Mn values of 3.5-17.5 kgmol-1. The influence of reaction temperature, the amount of enzyme and the presence of water in the reaction medium were shown to be important factors on the high molecular weight fraction and were investigated in detail [26b]. Comparison of optical rotation values for polymers prepared by... 

Single-step synthesis of polyester macromonomers was achieved by lipase-catalyzed polymerization of lactones in the presence of vinyl esters acting as terminator ( terminator method ) (187,188). A methacryl-type poly(DDL) macromonomer was obtained using vinyl methacrylate (12.5 or 15 mol% based on DDL) and lipase PF as terminator and catalyst, respectively. By the addition of divinyl sebacate, the telechelic polyester having a carboxylic acid group at both ends was synthesized. 

Lipase CA catalyzed the polymerization of cyclic dicarbonates, cyclo-bis(hexamethylene carbonate) and cyclobis(diethylene glycol carbonate), to give the corresponding polycarbonates (214). The enzymatic copolymerization of cy-clobis(diethylene glycol carbonate) with DDL produced a random ester-carbonate copolymer. Enzymatic synthesis of poly(ester-carbonate) was also achieved by the copolymerization of l,3-dioxan-2-one and lactide (215). The PPL-catalyzed copolymerization at 100°C produced the copolymer with My, higher than 2x 10. ... 

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