Vine-twining polymerization

The vine-twining polymerization is a method for the preparation of well defined supramolecules, which are amylose pol5mer inclusion complexes (70). The method consists of the enz5matic pol5meriza-tion of a-D-glucose-l-phosphate catalyzed by phosphorylase in the presence of various S mthetic pol mers such as polyethers, polyesters, poly(ester ether)s, and amphiphilic block copol5mers. The IH-NMR spectra of the polymers indicated structures composed from amylose and guest pol mers. 

This is a phosphorylase-catalyzed enzymatic pol5rmerization of an a-D-glucose-l-phosphate from a maltoheptose in the presence of polycarbonates. Polycarbonates with a shorter methylene chain length such as poly(tetramethylene carbonate) is more favorable as the guest polymer to form the inclusion complex with amylose. 

It has been shown that amylose selectively includes poly(tetiahy-drofuran) or poly(6-valerolactone) fromamixture of two resemblant polyethers, i.e., poly(oxetane) and poly(tetrahydrofuran), or also a mixture of two resemblant polyesters in vine-twining pol5meriza-tion (73). The highest priority on the inclusion of amylose showed poly(tetrahydrofuran). Also a selective inclusion according to the molecular weight of a poly(tetrahydrofuran) was demonstrated (74). 

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Even though the products are not block copolymer structures, the work of Kadokawa and colleagues should be mentioned here. In a process that the authors named vine-twining polymerization (after the way that a vine plant grow helically around a support rod), the enzymatic polymerization of amylose is performed in the presence of synthetic polymers in solution, and the authors showed that the grown amylose chains incorporate the polymers into its helical cavity while polymerizing [184-191]. 

Figure 9.8 Schematic representation of the concept of vine-twining polymerization. (Reproduced with permission from [112]. Copyright (2005) Wiley Periodicals, Inc.).

The preparation of inclusion complexes composed of amylose and hydrophobic polycarbonates have been achieved by vine-twining polymerization (71,72). The structure of such complexes is shown in Figure 1.6. 

Vine-Twining Polymerization to Form Inclusion Supramolecules... 

Fig. 2 Image of vine-twining polymerization using various guest polymers to form inclusion nanocomplexes...

When the vine-twining polymerization was conducted using optically active polyesters, poly(lactide)s (PLAs), which had three kinds of the stereoisomers, i.e., poly(L-lactide) (PLLA), poly(D-lactide) (PDLA), and poly(DL-lactide) (PLDLA), as guest polymers, the author found that amylose, produced by the enzymatic polymerization, perfectly recognized the chirality in PLAs on complexation and... 

Hierarchically Fabrication of Amylosic Supramolecular Nanocomposite Hydrogel and Film by Vine-Twining Polymerization Approach... 

Fig. 3 Preparation of supramolecular nanocomposite hydrogel through inclusion complexation by vine-twining polymerization using PAA-Na-g-PVL...

Fig. 5 Preparation of supramolecular nanocomposite film through hydrogelation by vine-twining polymerization using CMC-g-PCL...

F. 6 Preparation of supramolecular polymtaic nanocomposite by vine-twining polymerization using G7-PLLA as primer-guest eonjugate... 

In this chapter, an overview of hierarchically fabrication of eco-friendly supramolecular nanocomposites by means of inclusion complexation by amylose in the vine-twining polymerization was presented. The method was achieved by the phosphorylase-catalyzed enzymatic polymerization in the presence of the designed graft copolymers with guest polymeric chains. Inclusion complexation of amylose chains with guest chains in the intermolecular graft copolymers took place with the progress of the polymerization to construct the supramolecular nanocomposite... 

Because the vine-twining polymerization based on the enzymatic polymerization provides amylosic supramolecular nanocomposites with well-defined stractures, which are hardly produced by conventional chemical synthetic method, the present approach will be extended to the systems using newly designed guest polymer components with hierarchically ordered stracture. Accordingly, the approach has a potential to fabricate additional eco-friendly supramolecular nanocomposites. Furthermore, the eco-liiendly supramolecular nanocomposites based on amylose are practically applicable to the biomedical and environmentally benign materials in the future. 

Kadokawa J, Kaneko Y, Nagase S, Takahashi T, Tagaya H (2(X)2) Vine-twining polymerization amylose twines around polyethers to form amylose-polyether inclusion complexes. Chem Eur J 8 3321-3326... 

Kadokawa J, Nakaya A, Kaneko Y, Tagaya H (2003) Preparation of inclusion complexes between amylose and ester-containing polymers by means of vine-twining polymerization. Macromol Chem Phys 204 1451-1457... 

Kaneko Y, Beppu K, K5mtoku T, Kadokawa J (2009b) Selectivity and priority on inclusion of amylose toward guest polyethers and polyesters in vine-twining polymerization. Polym J 41 279-286... 

Nakai H, Kitaoka M, Svensson B, Ohtsubo K (2013) Recent development of phosphorylases possessing large potential for oligosaccharide synthesis. Curr Opin Chem Biol 17 301-309 Nomura S, Kyotoku T, Shimomura N, Kaneko Y, Kadokawa J (2011) Preparation of inclusion complexes composed of amylose and biodegradable poly(glycolic acid-co-e-caprolactone) by vine-twining polymerization and their lipase-catalyzed hydrolysis behavior. Polym J 43 971-977... 

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