Enzyme-catalyzed polymerizations at higher temperatures: Synthetic methods to produce polyamides and new poly(amide-co-ester)s

• Published in: Journal of molecular catalysis. B, Enzymatic Vol. 76; pp. 94 - 105
• Main Authors: Ragupathy, Lakshminarayanan, Ziener, Ulrich, Dyllick-Brenzinger, Rainer, von Vacano, Bernhard, Landfester, Katharina
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2012; Elsevier
• Subjects: Bioconversions. Hemisynthesis; Biological and medical sciences; Biotechnology; biphenyl; catalytic activity; composite polymers; Copolymerization; diamines; Enzymatic polymerization; Enzyme-catalyzed polycondensation; esters; ethylene; Fundamental and applied biological sciences. Psychology; High temperature reaction; matrix-assisted laser desorption-ionization mass spectrometry; melting; Methods. Procedures. Technologies; microstructure; molecular weight; nuclear magnetic resonance spectroscopy; Poly(amide-co-ester); Polyamide; polyamides; polyesters; polymerization; temperature; thermal degradation; toluene; transmission electron microscopy; yields; Polyamide; High temperature reaction; Enzymatic polymerization; Copolymerization; Enzyme-catalyzed polycondensation; Poly(amide-co-ester); Temperature; Polymerization; Enzymatic catalysis; High temperature; Method; Ester; Enzymatic reaction
• ISSN: 1381-1177; 1873-3158
• DOI: 10.1016/j.molcatb.2011.11.019

[Display omitted] ► We show the novozyme-435 catalyzed polycondensation to yield particulate polyamides and poly(amide-co-ester)s. ► A three-step procedure yields 97% amide bond formation. ► A new series of poly(amide-co-ester)s were obtained. ► We show melting and thermal degradation behaviors of these copolymers ► The microstructure of the polyamides was investigated by MALDI-TOF MS, the morphology by TEM. Novozyme-435 (N-435) catalyzed polycondensation reaction between different aliphatic (oligo)esters and diamines by precipitation polymerization at elevated temperatures yields various particulate polyamides and poly(amide-co-ester)s. The reaction between diethylsebacate (DES) and 1,8-diaminooctane (DAO) at 60°C in dried toluene leads to a low Mn polyamide (NMR: Mn=520gmol−1 GPC: Mn=2000gmol−1 with Mw/Mn=1.3). An improved three-step procedure with an adjusted temperature profile and an optimized amount of enzyme in dried diphenyl ether, yields 97% amide bond formation and a polymer with increased molecular mass (NMR: Mn=5380gmol−1, GPC: Mn=4960gmol−1 with Mw/Mn=3.5). Three step ring-opening and polycondensation reactions between a cyclic ester (ethylene tridecanedioate) with three different diamines were also performed in dried toluene to obtain the corresponding polyamides. Here, diamine with higher alkyl chain length, i.e. 1,12-diaminododecane shows higher activity towards N-435 catalyzed amide bond formation and therefore the produced nylon-12,13 has higher molecular weight (GPC: Mn=8250gmol−1 and Mw/Mn=5.8) compared to the other nylons. By adopting the three step synthetic protocol, a new series of poly(amide-co-ester)s with Mn up to 17,550gmol−1 were produced. Melting and thermal degradation behaviors of these copolymers are compared with pure nylon-8,10 and polyester by DSC and TGA. The microstructure of the synthesized polyamides with different end groups was investigated by MALDI-TOF MS analysis while the particles’ morphology was studied by TEM analysis.