Solvent-Free Adipic Acid/1,8-Octanediol Condensation Polymerizations Catalyzed by Candida antartica Lipase B

Abstract

Bulk condensation polymerizations of adipic acid and octanediol, catalyzed by Candida antartica Lipase B (CALB), were investigated. The polymers formed by 8 and 24 h polymerizations using CALB immobilized on Accurel and Lewatit had similar molecular weights (e.g., M n at 24 h ≈15 000). CALB "free" of the immobilization resin was also active for the polymerization but, relative to its immobilized forms, gave slower chain growth (M n ≈ 10 000 by 48 h). For all three catalyst systems at degree of polymerization (DP) g 20, dispersity (Mw/Mn) was e1.5. Since random processes of step-growth condensation polymerizations give dispersity values g 2, the dispersity of products obtained using CALB as the catalyst is believed to result from the unique chain length or mass selectivity of the lipase. Gel permeation chromatograms showed that between 15 min and 4 h chain growth occurred rapidly so that the fraction of product with M p values > 2910 increased from 28 to 78%. At 70°C the catalyst activity at 4 h remained unchanged but decreased by 15 and 21% at 24 and 48 h. Unexpectedly, an increase in the concentration of CALB on Lewatit from 0.1 to 1 wt % protein resulted in only a small increase in M n (e.g., at 24 h, 14 500 vs 17 800). However, decrease in the percent protein to 0.5% had a large detrimental effect. Between 65 and 90°C the polymerizations occurred with little dependence on the reaction temperature.

Immobilization of Candida antarctica lipase B on Polystyrene Nanoparticles

“…[1][2][3] By enzyme immobilization, catalysts can be developed with significant advantages relative to free enzyme. [4][5][6][7][8] Many literature reports describe the high utility of immobilized Cal-B for chemical transformations of low molar mass compounds, [9,10] and polymerization reactions. [11,12,13] Adsorption of an enzyme onto a surface can induce conformational changes which affect the rate and specificity of the catalyst.…”

Chemo enzymatic Synthesis for Poly3-hydroxypropionate in Solvent-free System

“…(Figure 3) of this reaction was report by Nobles and coworkers [18].First the substrate with the lipase to form an acyl enzyme intrmediate.The second step this acyl enzyme intermediate reacted with hydroxyl end of the growing polymer chain. To improve the conversion and molecules weight, in enzymatic catalyzed condensation polymerization reduced pressure was used to facilitate removal one product methanol [15]. Lipase Candida Antarctic lipase Novozym435 catalyzed the condensation polymerization of 3-hydroxypropionate methyl ester to poly3-hydroxypropionate under variety conditions.…”

“…Kumar et al copolymerized adipic and sorbitol in bulk using Novozyme-435 10% relative to monomers after 48h give a water soluble polymer (Mw17030) and adipic 1,8-octanediol and sorbitol were also compolymerized for a water insoluble polymer in the molar ratio 50:35:15(Mw1.17×105). [14]Mahapatro and coworkers use Novozyme435(1wt%relative the total weight of monomer) catalysized adioi and 1,8-octanediol copolymerization in vacuum ,after 24h a copolymer Mn nearly 15000 was received [15]. Kulshrestha et al use Novozyme-435(10wt%relative to total monomer weight)at 80℃ in vacuum catalyzed adipic acid bis(hydroxymethyl)butyric acid and 1,8-octanediol copolymerization when the monomer ratio of bis(hydroxymethyl)butyric acid from9-45% after 42h a linear polyester Mw2300-21900 was accepted [16].…”

Chemoenzymatic synthesis of an AB‐type diblock copolymer combining enzymatic self‐condensation polymerization and atom transfer radical polymerization

“…The reaction mixture was filtered, and the filtrate was extracted with 5% aqueous HCl (2 Â 100 mL), Na 2 CO 3 (2 Â 100 mL), and a saturated brine (2 Â 100 mL) solution. The organic phase was dried over MgSO 4 , and the crude product was purified by column chromatography (silica gel, CHCl 3 ) to give a viscous and transparent liquid. The product was stored over freshly activated type-4 molecular sieves.…”

“…Biocatalytic approaches have been employed in the design and fabrication of various polyesters with different structures for increasing demands. 1,2 For example, Novozyme 435 (immobilized Candida antarctica lipase B) has been recognized widely as an effective and versatile biocatalyst in polyester synthesis via both ring-opening polymerization (ROP) of lactones (e.g., -caprolactone) 3,4 and polycondensation of either diacid (its derivatives)/diol combinations [5][6][7] or hydroxyacid (its derivatives); 4,8 furthermore, its scope has been further widened by the preparation of block copolymers 9,10 and hyperbranched copolymers. 11 However, the full exploitation of biocatalysis in polymer synthesis will require the development of mutually compatible chemo-and biocatalytic methods.…”