1. Cycloalkyl-substituted salicylaldimine-nickel(II) complexes as mediators in controlled radical polymerization of vinyl acetate
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Talita T. Silva, Benedito S. Lima-Neto, N. C. Batista, Beatriz E. Goi, Carlos R. B. Tasso, Pedro I. S. Maia, Yan F. Silva, Antonio E.H. Machado, Valdemiro P. Carvalho-Jr, José L. Silva Sá, Univ Estadual Piaui, Universidade Estadual Paulista (Unesp), Universidade Federal de Uberlândia (UFU), Univ Fed Triangulo Mineiro, and Universidade de São Paulo (USP) more...
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Schiff base ,polyVAc ,Polymers and Plastics ,Radical polymerization ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Nickel ,OMRP ,NÍQUEL ,chemistry ,Polymer chemistry ,vinyl acetate ,Materials Chemistry ,Ceramics and Composites ,Vinyl acetate ,nickel complexes ,0210 nano-technology - Abstract
Made available in DSpace on 2019-10-04T12:16:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-09 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nickel(II) complexes of Schiff base derived from cycloalkylamines (cycloalkyl = cyclopentyl (cpen), cyclohexyl (chex), and cycloheptyl (chep)) were synthesized: [Ni-II(L-cpen)(2)] (1), [Ni-II(L-chex)(2)] (2), and [Ni-II(L-chep)(2)] (3). The Schiff base-Ni-II complexes 1-3 were characterized by FTIR, UV-Vis, elemental analysis, and computational methods. Electrodeposited films of complexes 1-3 were obtained by potential cycling CH2Cl2 on platinum electrode, and their electrochemical behavior were characterized by cyclic voltammetry. The polymerization of vinyl acetate (VAc) initiated by azobisisobutyronitrile (AIBN) at 55 degrees C were conducted according to an organometallic-mediated radical polymerization (OMRP) mechanism. The best conversions were obtained using a ratio of [VAc]/[AIBN]/[Ni] = 542/3.25/1, reaching 50, 69 and 85% in 12 h for 1, 2 and 3, respectively. The kinetic of polymerization mediated by complex 1 exhibited a linear dependence of ln([VAc](0)/[VAc]) versus time, supporting a constant radical concentration; while for the complexes 2 and 3, the radical concentration was constant for a short period of time. The increase of molecular weights with the conversion coupled with low polydispersities indicate a certain level of control of the polymerization when using the complexes [Ni-II(L (R))(2)] as controlling agents. Univ Estadual Piaui, Ctr Ciencias Nat, BR-64002150 Teresina, PI, Brazil Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil Univ Fed Uberlandia, Inst Quim, Uberlandia, MG, Brazil Univ Fed Triangulo Mineiro, Dept Quim, Uberaba, Brazil Univ Sao Paulo, Inst Quim Sao Carlos, Sao Carlos, SP, Brazil Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil FAPESP: 2013/11883-0 FAPESP: 2013/10002-0 more...
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- 2019
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