Synthesis of polymers from carbon dioxide

The carbon dioxide content in air is ca. 0.03〜0.04%. Although the concentration is low, the amount is abundant. Accordingly, the transformation of carbon dioxide is a good solution for the forthcoming problem on the lack of petroleum resources, if the transformation proceeds in low-energy cost. We focused on the reaction of carbon dioxide and epoxides, which proceeds smoothly under relatively mild conditions.

Synthesis of polymers bearing five-membered cyclic carbonate moieties

Functions of polymers bearing five-membered cyclic carbonate moieties

Gas-solid phase reactions of gaseous carbon dioxide with solid polymers bearing oxirane
 Kihara and Endo reported gas-solid phase fixations of carbon dioxide into films of poly(glycidyl methacrylate) containing ammonium salts, although the fixation degree could not be quantitative due to the concomitant anionic cross-linking of the oxirane groups (Kihara & Endo J. Chem. Soc. Chem. Commun. 1994, 937). We optimized the conditions for this gas-solid phase reaction, and attained quantitative incorporation of carbon dioxide. Both soluble and insoluble polymers could be obtained keeping high fixation efficiency (> 95%).

Concurrent radical polymerization and CO2 fixation for utilizing CO2 by low energy cost

For utilizing carbon dioxide by low energy cost, we developed carbon dioxide proceeding concurrently with other reactions. As depicted in the aboveindicated scheme, carbonate-containing polymers were obtained by radical polymerization of GMA accompanied by carbon dioxide fixation. The unit ratio can be controlled. The energy required for this concurrent reaction is almost competitive with either of the reactions (i.e., radical polymerization of GMA or reaction of carbon dioxide with epoxide), and it indicates that carbon dioxide could be transformed by low energy cost.

Synthesis and application of poly(hydroxyurethane) prepared by polyaddition of five-membered cyclic carbonates and diamines

Five-membered cyclic carbonates react selectively with primary amines to give urethanes with hydroxyl groups (hydroxyurethane). Using bifunctional analogues affords polyurethane bearing hydroxyl groups in the side chain (poly(hydroxyurethane)). We are exploring the efficient synthetic process for poly(hydroxyurethane) and the applications to materials for electronic devices, adhesive, and so forth.

Detail of the works before 2005 is described in the following review.

Carbon Dioxide and Carbon Disulfide as Resources for Functional Polymers.
Ochiai, B.; Endo, T. Prog. Polym. Sci. 30 (2), 183-215 (2005) Link to Science Direct

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