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Enzyme catalysis in the synthesis of polyaniline is reviewed. Oxidoreductase enzymes and biomimetic catalysts have been used for the polymerization in aqueous, aqueous organic, and interfacial or templating environments to optimize polymer features. The results showed significant structural control in the presence of templates to produce water soluble and processable polymeric materials. Dip-pen nanolithography technology has also been used to process these materials into conducting nano-wires and thus provides new opportunities for the formation of electrical contacts among biological components for various applications such as synthetic biological interfaces. [ABSTRACT FROM AUTHOR]

Enzymatic synthesis and properties of polymers from polyphenols are reviewed. Catechol derivatives were subjected to oxidative polymerization and curing. High-performance coatings were prepared from urushiol and its analogues using laccase as a catalyst. Flavonoids were oxidatively polymerized by polyphenol oxidase, laccase, and peroxidase to produce the flavonoid polymers. The conjugation of polyphenols on amine-containing polymers took place via the enzyme catalysis. The flavonoid-containing polymers showed good antioxidant properties and enzyme inhibitory effects. [ABSTRACT FROM AUTHOR]

An enzyme can act as a powerful catalyst for the production and chemical recycling of green and sustainable polymers via a ring-opening polymerization. Also, enzymes will provide versatile synthetic tools for regio- and enantioselective polymerizations. In this article, lipase-catalyzed ring-opening polymerization and copolymerization of small-sized four-membered lactones to macrolides and cyclic oligomers having a molecular weight of a few hundred into high-molecular-weight polyesters, ring-opening polymerization of substitutedβunsubstituted cyclic carbonates and cyclic phosphates into polycarbonates and polyphosphates, and the mechanism of lipase-catalyzed ring-opening polymerization of lactones and cyclic carbonates are reviewed. Also degradative transformation of polyesters and polycarbonates into the corresponding cyclic oligomers as repetitive chemical recycling and trends for enzymatic ring-opening polymerization and degradation are described. [ABSTRACT FROM AUTHOR]

This chapter deals with the peroxidase-catalyzed polymerization of phenol and its derivatives. Such a polymerization needs an oxidation reagent, normally hydrogen peroxide. Since this type of polymerization is believed to be a potential environmentally friendly alternative process for the production of phenol--formaldehyde resins, it has been investigated thoroughly by many research groups. Typical research challenges in this field are investigations regarding the polymerization mechanism, the mechanism of enzyme catalysis, the structure of the resulting phenol polymers, and, needless to say, the synthesis of new materials. A comprehensive overview is given that covers the progress made during recent years, starting from the synthesis of simple resins obtained from unsubstituted phenol and leading up to the production of polyaromatic materials having multiple reactive groups in the side chain. One key for successful work in this field is to understand the characteristics of the enzyme. However, it is also important to be familiar with the influences of different solvents and various concentrations of the reactants (monomer, enzyme, hydrogen peroxide) on the yield, molecular weight, and structure of the resulting polymers. In other words, peroxidase-catalyzed polymerization is an interdisciplinary area covering different fields, mainly biochemistry, organic chemistry, and polymer chemistry for the synthesis of phenol polymers, as well as physical chemistry to understand their properties. This chapter tries to emphasize this aspect. [ABSTRACT FROM AUTHOR]

The in vitro enzyme-mediated polymerization of vinyl monomers is reviewed with a scope covering enzymatic polymerization of vitamin C functionalized vinyl monomers, styrene, derivatives of styrene, acrylates, and acrylamide in water and water-miscible cosolvents. Vitamin C functionalized polymers were synthesized via a two-step biocatalytic approach where vitamin C was first regioselectively coupled to vinyl monomers and then subsequently polymerized. The analysis of this enzymatic cascade approach to functionalized vinyl polymers showed that the vitamin C in polymeric form retained its antioxidant property. Kinetic and mechanistic studies revealed that a ternary system (horseradish peroxidase, H2O2, initiator β-diketone) was required for efficient polymerization and that the initiator controls the characteristics of the polymer. The main attributes of enzymatic approaches to vinyl polymerization when compared with more traditional synthetic approaches include facile ambient reaction environments of temperature and pressure, aqueous conditions, and direct control of selectivity to generate functionalized materials as described for the ascorbic acid modified polymers. [ABSTRACT FROM AUTHOR]

In vitro synthesis of polyesters by polycondensation using isolated enzymes as catalyst via nonbiosynthetic pathways is reviewed. In most cases, lipase was used as catalyst and the polyesters were obtained from oxyacids, their esters, and dicarboxylic acid derivatives/glycols. Enzymatic polymerization proceeded under mild reaction conditions in comparison with chemical processes. By utilizing characteristic properties of lipases, regio- and enantioselective polymerizations proceeded to give functional polymers, most of which are difficult to synthesize by conventional methodologies. [ABSTRACT FROM AUTHOR]

Polysaccharides are formed by repeated glycosylations between a sugar donor and a sugar acceptor. This chapter reviews the in vitro synthesis of polysaccharides by “enzymatic polymerization.” As catalyst, a hydrolase enzyme is used where the monomer was designed based on the concept of a “transition-state analog substrate” (TSAS), sugar fluoride monomers for the polycondensation, and sugar oxazoline monomers for the ring-opening polyaddition. Enzymatic polymerization enabled the first in vitro synthesis of natural polysaccharides such as cellulose, xylan, chitin, hyaluronan, and chondroitin, and also of unnatural polysaccharides such as a cellulose-xylan hybrid, a regularly methylated cellulose, and derivatives of hyaluronan and chondroitin. The polymerization mechanism is discussed here. Mutant enzymes were effective for polysaccharide synthesis, where only polycondensation of monomers was induced by suppressing the hydrolysis activity. The polymerization principle was extended to a stepwise synthesis of oligosaccharides. By using characteristics of the polymerization to produce a polysaccharide by a single step, in situ observations of the polymerization reaction by TEM, POM, SEM, and SANS revealed the formation of various high-order molecular structures from the polysaccharide molecules. [ABSTRACT FROM AUTHOR]