Reference

Polymerization of methyl methacrylate initiated by the redox system cerium(IV)/isobutyl alcohol

Polymerization of methyl methacrylate initiated by the redox system cerium(IV)/isobutyl alcohol. Fernandez, M. D.; Pelayo, A.; Otero, T. F.; Guzman, G. M. (Dep. Quim. Fis. Macromol., Fac. Cienc. Quim., San Sebastian, Spain). J. Polym. Sci., Polym. Lett. Ed., 23(2), 79-83 (English) 1985. CODEN: JPYBAN. ISSN: 0360-6384. DOCUMENT TYPE: Journal CA Section: 35 (Chemistry of Synthetic High Polymers) The polymn. rate of Me methacrylate (I) [80-62-6] in aq. soln. at 30° in the presence of a redox catalyst system contg. ceric ammonium nitrate [16774-21-3] in HNO3 and iso-BuOH (II) [78-83-1] increased with increasing I and II concns. and with increasing Ce4+ concn. up to 3.0 ′ 10-3 M. The polymn. rate was of the 1/2 and 3/2 order in II and I, resp., and decreased at Ce4+ concn. >1.5 ′ 10-2 M. The rate of Ce4+ disappearance was directly proportional to Ce4+ concn. but independent of I concn. A reaction scheme was proposed involving the initiation by primary radicals produced by the decompn. of a Ce4+-II complex and the termination by mutual interaction between growing polymeric radicals and an oxidative termination of primary radicals.

Treatment of waste solution containing ammonium hexanitratocerate

Treatment of waste solution containing ammonium hexanitratocerate. Kamata, Nori (Hitachi, Ltd., Japan). Japan. Kokai JP 52068860 8 Jun 1977 Showa, 2 pp. (Japanese). (Japan). CODEN: JKXXAF. CLASS: IC: C02C005-00. APPLICATION: JP 75-145002 8 Dec 1975. DOCUMENT TYPE: Patent CA Section: 60 (Sewage and Wastes) A waste soln. contg. (NH4)2Ce(NO3)6 (I) [16774-21-3], Cr6+, Ni ion, and Ce ion is treated with NaHSO3 to reduce Cr6+ to Cr3+, then the soln. is treated with Ca(OH)2 to coppt. Ni and Ce. The method is useful for removing Ni, Cr, and Ce from a spent etching soln. Thus, a waste soln. contg. 30% I, Ni ion, and Cr6+ ion was dild. 10-fold to contain ~20 ppm each of Cr6+ and Ni ion, then Cr6+ was reduced to Cr3+ with NaHSO3 at redox potential 200 mV, and Ca(OH)2 was added to pH 10-11 to ppt. Cr, Ni, and Ce. A treated soln. contained ~0.01 ppm of Cr6+ or Ni ions.