Cycloalkyl-substituted salicylaldimine-nickel(II) complexes as mediators in controlled radical polymerization of vinyl acetate

Author(s)

Silva, Talita T. ^{[1, 2]} ; Silva, Yan F. ^[1] ; Machado, Antonio E. H. ^{[2, 3]} ; Maia, Pedro Ivo S. ^[4] ; Tasso, Carlos R. B. ^[5] ; Lima-Neto, Benedito S. ^[5] ; Silva Sa, Jose L. ^[2] ; Carvalho-Jr, Valdemiro P. ; Batista, Nouga C. ^[2] ; Goi, Beatriz E. ^[6]

Affiliation

^[1] Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP - Brazil

^[2] Univ Estadual Piaui, Ctr Ciencias Nat, BR-64002150 Teresina, PI - Brazil

^[3] Univ Fed Uberlandia, Inst Quim, Uberlandia, MG - Brazil

^[4] Univ Fed Triangulo Mineiro, Dept Quim, Uberaba - Brazil

^[5] Univ Sao Paulo, Inst Quim Sao Carlos, Sao Carlos, SP - Brazil

^[6] Carvalho-Jr, Jr., Valdemiro P., Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP - Brazil

• Document type: Journal article
• Source: Journal of Macromolecular Science Part A-Pure and Applied Chemistry; v. 56, n. 12, p. 1132-1140, DEC 2 2019.
• Web of Science Citations: 0

Abstract

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. (AU)

• FAPESP's process: 13/11883-0 - Synthesis of organocobalt (iii) complexes as clean sources of radicals for cobalt mediated radical polymerization
• Grantee: Beatriz Eleutério Goi Carvalho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/10002-0 - Development of ruthenium complexes as dual catalytic systems in simultaneous polymerization ROMP/ATRP
• Grantee: Valdemiro Pereira de Carvalho Júnior
• Support Opportunities: Research Grants - Young Investigators Grants