Polymers enzymatic grafting

Graft copolymers were prepared by both classical strategies, i.e., from enzymatically obtained macromonomers using subsequent chemical polymerization and by enzymatic grafting from hydroxy-functional polymers. 

Graft copolymers were prepared by both classical strategies, that is, from enzymatically obtained macromonomers by subsequent chemical polymerization and by enzymatic grafting from hydroxyl functional polymers. Kalra et al. studied the synthesis of PPDL graft copolymers from macromonomers, which were obtained by the enzymatic ROP of pentadecalactone (PDL) from hydroxyethyl methacrylate (HEMA) and polyethylene glycol) methacrylate (PEGMA) [40]. Subsequently graft copolymers were obtained by free radical polymerization of the macromonomers. A similar approach was published by Srivastava for the HEMA-initiated enzymatic ROP of CL and subsequent free radical polymerization [41]. 

Duxbury, C.J. Heise, A. Selective enzymatic grafting by steric control ACS Polymer Preprints, 2006, 47(2), 271. 

The membrane of a hollow-fiter form is a convenient polymeric material in that expansion from a laboratory to a plant scale can be carried out simply by bundling the hollow fibers into a hollow-fiber membrane module [14,15]. The phenomenon of multilayer binding of the enzymes into the polymer chains grafted onto the porous hollow-fiber membrane is applicable to other enzymatic reactions at a high throughput. 

Fig. 2 Functional polymers derived from enzymatic grafting and/or copolymerisation of different silanes (tetraethylorthosilane and aminoslinane)...

Another class of rod-coil systems with helical rod segments is derived from amylose as one block. Most copolymer systems with amylose as one segment are based on an enzymatic grafting from polymerization with potato phosphorylase which was pioneered by Beate Pfannemiiller. Linear, star, and comblike polymers carrying amylose chains were reported by Pfannemiiller et al. [122-125]. Stadler and coworkers reported rod-coil systems composed of amylose blocks with polysiloxanes [126,127] (comblike structures) and polystyrene [128] (blocklike structures). Comblike structures based on polystyrene with amylose entities were synthesized by Kobayashi et al. [129]. 

The enzymatic polymerization of lactones could be initiated at the hydroxy group of the polymer, which expanded to enzymatic synthesis of graft copolymers. The polymerization of c-CL using thermophilic lipase as catalyst in the presence of hydroxyethyl cellulose (HEC) film produced HEC-gra/f-poly( -CL) with degree of substitution from 0.10 to 0.32 [102]. 

Szleifer I (1997) Protein adsorption on surfaces with grafted polymers a theoretical approach. Biophys J 72 595-612 Tanford C (1973) The hydrophobic effect. John Wiley Sons, Inc., Hoboken Van Dulm P, Norde W, Lyklema J (1981) Ion participation in protein adsorption at solid surfaces. J Colloid Interf Sci 82 77-82 Zoungrana T, Findenegg GH, Norde W (1997) Structure, stability and activity of adsorbed ensymes. J Colloid Interf Sci 190 437-448 Zoungrana T, Norde W (1997) Thermal stability and enzymatic activity of a-chymotrypsin adsorbed on polystyrene surfaces. Colloid Surf B 9 157-167... 

Peterson DS, Rohr T, Svec FK, Frechet JMJ (2003) Dual-function microanalyt-ical device by in situ photolithographic grafting of porous polymer monolith integrating solid-phase extraction and enzymatic digestion for peptide mass mapping. Anal Chem 75 5328... 

Enzymatic polymerizations have been established as a promising and versatile technique in the synthetic toolbox of polymer chemists. The applicability of this technique for homo- and copolymerizations has been known for some time. With the increasing number of reports on the synthesis of more complex structures like block copolymers, graft copolymers, chiral (co)polymers, and chiral crosslinked nanoparticles, its potential further increases. Although not a controlled polymerization technique itself, clever reaction design and integration with other polymerization techniques like controlled radical polymerization allows the procurement of well-defined polymer structures. Specific unique attributes of the enzyme can be applied... 

Chapter 4 shows that the range of polymeric structures from enzymatic polymerization can be further increased by combination with chemical methods. The developments in chemoenzymatic strategies towards polymeric materials in the synthesis of polymer architectures such as block and graft copolymers and polymer networks are highlighted. Moreover, the combination of chemical and enzymatic catalysis for the synthesis of unique chiral polymers is discussed. 

Peterson, D.S. Rohr, T. Svec, F. Frechet, J.M.J. Dual-function Microanalyti-cal Device by In Situ Photolithographic Grafting of Porous Polymer Monolith Integrating Solid-Phase Extraction and Enzymatic Digestion for Peptide Mass Mapping, Anal. Chem. 75, 5328-5335 (2003). 

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