Evaluation of Stability of Amylose Inclusion Complexes Depending on Guest Polymers and Their Application to Supramolecular Polymeric Materials
This paper describes the evaluation of the stability of amylose–polymer inclusion complexes under solution state in dimethyl sulfoxide (DMSO) depending on guest polymers. The three complexes were prepared by the vine-twining polymerization method using polytetrahydrofuran (PTHF), poly(ε-caprolactone) (PCL), and poly(l-lactide) (PLLA) as guest polymers. The stability investigation was conducted at desired temperatures (25, 30, 40, 60 °C) in DMSO solutions of the complexes. Consequently, the amylose–PTHF inclusion complex was dissociated at 25 °C, while the other complexes were stable under the same conditions. When the temperatures were elevated, the amylose–PCL and amylose–PLLA complexes were dissociated at 40 and 60 °C, respectively. We also found that amylose inclusion supramolecular polymers which were prepared by the vine-twining polymerization using primer-guest conjugates formed films by the acetylation of amylose segments. The film from acetylated amylose–PLLA supramolecular polymer had higher storage modulus than that from acetylated amylose–PTHF supramolecular polymer, as a function of temperature.
Synthesis and gel formation of hyperbranched supramolecular polymer by vine-twining polymerization using branched primer–guest conjugate
Abstract In this article, we report the synthesis of a hyperbranched supramolecular polymer composed of continuum of amylose-poly( l -lactide) (PLLA) inclusion complexes by phosphorylase-catalyzed enzymatic polymerization using a branched maltoheptaose-PLLA conjugate according vine-twining polymerization manner. The X-ray diffraction and 1H NMR measurements indicated the presence of the inclusion complex structure in the product. The GPC peak of the amylose segment, which was obtained by alkaline hydrolysis of the vine-twining polymerization product, shifted to the lower molecular weight region, compared with that of the product, supporting the structure of the supramolecular polymer. A hydrogel of the supramolecular polymer was obtained through the formation of an ion gel with an ionic liquid. Furthermore, a cryogel with porous morphology was produced by lyophilization of the hydrogel.
Enzyme-responsive molecular assembly system with amylose-primer surfactants.
The association of amylose-primer surfactants was controlled by changing the amphiphilicity with a chain-elongation reaction triggered by the addition of phosphorylase. By using this property, the micelle-to-vesicle transition of mixed lipid/ primer systems can be controlled.