Mikiji Miyata

Inclusion Polymerization of Isoprene in the Channels of Sepiolite

We have tried an inclusion polymerization in the channels of sepiolite, and studied the structure of polymer formed inside and outside the channels. Isoprene was polymerized not only on the outer surface but also in the channels of the sepiolite at 25 °C. Strong Brønsted acid sites in the outer and inner surfaces of the sepiolite intitiate a polymerization of isoprene and styrene. Double bonds of polyisoprene formed in the channels were protonated by the strong Brønsted acid sites of the sepiolite. The interaction between the protonated double bonds and the acid sites changed the color to violet. The outer surface of the folded sepiolite whose channels were collapsed formed a usual polyisoprene which caused no color change.

Asymmetric inclusion polymerization in apocholic acid canals

SummaryAsymmetric inclusion polymerization of four prochiral diene monomers was studied in apocholic acid canal complexes. All the polymers obtained were found to show specific rotations of (−) sign, different from the cases of polymerization in deoxycholic acid canals.

Polymerization of Diene and Diyne Monomers in Deoxycholic and Apocholic Acid Inclusion Compounds

Abstract One-dimensional polymerization of conjugated diene and diyne monomers in channels of deoxycholic and apocholic acid inclusion compounds is discussed. The polymerization exhibited the following remarkable features on the basis of a one-dimensional character of the molecular assemblies, in contrast to that in solution or the solid state: (i) stabilized propagating radicals, (ii) decreased reaction rates, and (iii) an efficient induction of regiospecificity and stereo-specificity.

Inclusion Polymerization of Various Diene Monomers in Apocholic Acid Canals

The inclusion polymerization of diene monomers with different sizes and shapes in apocholic acid canals was studied under γ-ray irradiation. It was found that the sizes and shapes of monomers profoundly influenced the microstructures of the corresponding polymers obtained. Thus, polybutadiene contained a significant amount of 1, 2-units like usual radical polymerization in solution. Polyisoprene consisted of a mixture of head-to-tail and head-to-head (tail-to-tail) addition. The introduction of two methyl groups into butadiene led to the synthesis of polymers with almost exclusively head-to-tail, 1,4-trans structure.

Inclusion Polymerization of Diene and Diacetylene Monomers in Deoxycholic Acid and Apocholic Acid Canals

Inclusion polymerization is a unique one-dimensional polymerization which proceeds in a canal (channel) of inclusion compounds, and an excellent way for giving stereoregular polymers as well as composite materials at molecular level [1,2]. Such materials have a potential possibility to show some characteristic electrical, optical and magnetic properties in the inclusion state due to their one-dimensional structure.

Inclusion polymerization of 1,3-butadiyne in deoxycholic acid and apocholic acid canals☆

Abstract The inclusion polymerization of 1,3-butadiyne was studied at different temperatures, using deoxycholic acid and apocholic acid as the host molecules. The structure as well as the properties of the polymers obtained were measured in detail. The new composites of poly(1,3-butadiyne) were found to show unique (characteristic) spectroscopic properties and electric conductivity.