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Poly(cyanogen) and derived carbon fibers
988
POLY(CYANOGEN) AND DERIVED CARBON FIBERS
J.H. CHEN, P.H. CHANG and M.M. LABES Department of Chemistry, Temple University, Philadelphia, PA 19122 (U.S.A.)
Although insoluble polymers derived from cyanogen have been known since 1816, we have succeeded in preparing a linear, soluble polymer having the structure {C(CN) = N~ n with a molecular weight of approximately 5000. Our synthetic route is the electropolymerizatlon of cyanogen in a polar organic solvent containing an organic electrolyte. The polymerization proceeds through an interesting heterocyclic anion, C7N7-, as an intermediate, but little or none of this anion is incorporated in the polymer. However, when salts of this anion are used as the electrolyte in the polymerization, one begins to observe some incorporation of this heterocyclic structure into the polymer. Poly(cyanogen) (PCN) i~ an insulating solid showing high charge storage The expected group dipole moment of PCN in the all cis-form is 2.7 D. Preliminary measurements have been performed of the ferroelectric properties of polymer blends of PCN with good film-forming polymers, and a pyroelectric effect has been observed in some blends. Fibers drawn from solutions of PCN can be directly converted to carbon fibers via heat treatment in vacuo or inert atmosphere. Very low band gaps and high conductivities are observed starting at heat treatment temperatures as low as 700°C. The mechanical strengths of the fibers increase with increasing heat treatment temperature. The remarkable retention of morphological characteristics is followed by electron microscopy.
ACKNOWLEDGEMENT This work was supported by the National SeieRce Foundatlon-Solid State Chemistry under Grant No. DMR83-02329.
POLY(CYANOGEN) AND DERIVED CARBON FIBERS
J.H. CHEN, P.H. CHANG and M.M. LABES Department of Chemistry, Temple University, Philadelphia, PA 19122 (U.S.A.)
Although insoluble polymers derived from cyanogen have been known since 1816, we have succeeded in preparing a linear, soluble polymer having the structure {C(CN) = N~ n with a molecular weight of approximately 5000. Our synthetic route is the electropolymerizatlon of cyanogen in a polar organic solvent containing an organic electrolyte. The polymerization proceeds through an interesting heterocyclic anion, C7N7-, as an intermediate, but little or none of this anion is incorporated in the polymer. However, when salts of this anion are used as the electrolyte in the polymerization, one begins to observe some incorporation of this heterocyclic structure into the polymer. Poly(cyanogen) (PCN) i~ an insulating solid showing high charge storage The expected group dipole moment of PCN in the all cis-form is 2.7 D. Preliminary measurements have been performed of the ferroelectric properties of polymer blends of PCN with good film-forming polymers, and a pyroelectric effect has been observed in some blends. Fibers drawn from solutions of PCN can be directly converted to carbon fibers via heat treatment in vacuo or inert atmosphere. Very low band gaps and high conductivities are observed starting at heat treatment temperatures as low as 700°C. The mechanical strengths of the fibers increase with increasing heat treatment temperature. The remarkable retention of morphological characteristics is followed by electron microscopy.
ACKNOWLEDGEMENT This work was supported by the National SeieRce Foundatlon-Solid State Chemistry under Grant No. DMR83-02329.