Macromol. Chem. Phys. zyxwvut 196,3031 -3040 zyxwv (1995) zyxwvu 303 1 Characterization of dehydrochlorinated poly(viny1idene chloride) and the shock-compressed material Tamikuni Komatsu Masayuki Nomura Analytical Research Center, Asahi Chemical Industry Co. Ltd., 2-1 Samejima, Fuji, Sizuoka 416, Japan Youzou Kakudate, Syuzou Fujiwara National Institute of Materials and Chemical Research, Tsukuba, Ibaraki 305, Japan R. B. Heimann Chair of Technical Mineralogy, Freiberg University of Mining and Technology, D-09596 Freiberg, Federal Republic of Germany (Received December 13, 1994; revised manuscript of January 30, 1995) SUMMARY Dehydrochlorinated poly(viny1idenechloride) proved to be a conjugated polyene-polyene polymer. Shock compression of the polymer formed a large portion of graphite and trace amounts of diamond and of an unknown carbon. The unknown carbon belongs to the hexagonal crystal system and possesses the cell dimension a. zyxw = 0.338 nm. A comparison with known carbynes was made in terms of the crystalline parameters. Introduction The finding of new forms of carbon, fullerenes and nanotubes, has greatly contributed to the recent developments in carbon research. The study of carbon is coming into a new stage, and great interest is now concentrated on the search for other new carbon-based substances. Looking back upon the history of carbon, the discovery of carbynes by a Russian group in 1967 is noted. They prepared carbynes through oxidative polydehydroconden- sation of acetylene and defined carbynes as infinite one-dimensional carbon rods that are denoted as -C=C-(C=C),,-C=C- (a-carbyne) and =C=(C=C),=C= (P-carbyne) Strange to say, the chemical structure of carbynes has not been confirmed until now. Alternatively, synthetic carbynes obtained through contact heating of pyrolytic graphite at high temperature zyx 5,6), dehydrohalogenation of polyhalogen-containing polymers zyxwv 7, 8)r ion sputting of carbon film bombarded by Ar + ions9), evaporation of carbon by an electrical arc9), and dehalogenation of poly(tetrafluoroethy1ene) lo) have also been reported. These carbynes seem to leave some room for argument, because the products were assigned without confirmation of the chemical s t r u c t ~ r e ~ , ~ , ~ ) and were not structurally pure7s8, lo). Although carbynes are still mysterious, the structural images presented for carbynes are noteworthy in z 0 1995, Hiithig & Wepf Verlag, Zug CCC 1022-1352/95/$10.00