Polycyclic Carbonate Oligomer Synthesis

Five-membered cyclic carbonates are easily available as a result of the insertion of gaseous carbon dioxide into an oxirane ring (see review [12.]). Recent work in the field of new methods for preparing cyclic carbonates is dedicated primarily to the development of new catalytic systems and the synthesis of monofunctional compounds from epoxides and carbon dioxide (see, for example, reviews [13-16]). Monocyclic carbonates are used in a wide spectrum of applications solvents, components of liquid electrolytes, reactive diluents, chemical intermediates, and so on. It should be noted that this preparation also solves the problem of chemical fixation and utilization of C02. 

STRUCTURE 4.2 Example of polyfunctional cyclic carbonate-tricyclic carbonate on the base of propoxylated glycerin. (Reprinted from O. Figovsky and L. Shapovalov, Cyclocarbonate-Based Polymers Including Non-Isocyanate Polyurethane Adhesives and Coatings, in Encyclopedia of Surface and Colloid Science, ed. P. Somasundaran, vol. 3, 1633-1653. New York Taylor Francis, 2006. With permission.) 

At the same time there is the scarcity of commercially available polyfunctional cyclic carbonates (Structure 4.2). There are several methods for producing polymers or oligomers containing multiple cyclic carbonate groups  

A research team led by O. Figovsky synthesized aliphatic multifunctional cyclic carbonates from corresponding epoxies and carbon dioxide and NIPUs based on them [17,18], The authors tested some compositions polyfunctional carbonates synthesized in the laboratory, namely trimethylolpropane tricyclocarbonate (TMPTCC) and chlorine-contained aliphatic tricyclocarbonates (on the base of chlorine-contained aliphatic epoxy resins Oxilin ) and various diamines 2-methylpentam-ethylene diamine (MPMD), Dytek A, Invista Co. meta-xylenediamine (MXDA), Mitsubishi Gas Chem. Co. polyetheramineJeffamineEDR-148, Huntsman Co. and diethylenetriamine (DETA), D.E.H. 20, Dow Chemical Co. The properties of these materials are shown in Table 4.1. 

Some of the results are significantly better than previously achieved levels and offer good prospects for their practical use. 

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NIPU networks are created by the reaction between polycyclic carbonate oligomers and aliphatic or cycloaliphatic polyamines with primary amino groups [4], This forms a cross-linked polymer with p-hydroxy urethane groups of a different structure—polyhydroxyurethane polymer. Since NIPU is obtained without using highly toxic isocyanates, the process of synthesis is relatively safe for both humans and the environment in comparison to the production of conventional polyurethanes. Moreover, NIPU is not sensitive to moisture in the surrounding environment. 

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