Atom Transfer Radical Polymerization of Methyl Methacrylate Mediated by Grubbs 1st and 2nd Generation Catalysts: Insight into the Active Species

Autor(es)

Maria Beatriz A. Afonso ^[1] ; Lucas G. Gonçalves ^[2] ; Patrícia Borim ^[3] ; José Luiz S. Sá ^[4] ; Beatriz E. Goi ^[5] ; Valdemiro P. Carvalho-Jr. ^[6]

Afiliação do(s) autor(es)

^[1] Universidade Estadual Paulista. Faculdade de Ciências e Tecnologia - Brasil

^[2] Universidade Estadual Paulista. Faculdade de Ciências e Tecnologia - Brasil

^[3] Universidade Estadual Paulista. Faculdade de Ciências e Tecnologia - Brasil

^[4] Universidade Estadual do Piauí. GERATEC. Departamento de Química - Brasil

^[5] Universidade Estadual Paulista. Faculdade de Ciências e Tecnologia - Brasil

^[6] Universidade Estadual Paulista. Faculdade de Ciências e Tecnologia - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 28, n. 8, p. 1407-1413, 2017-08-00.

Resumo

Ruthenium benzylidene complexes were evaluated as catalysts in atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA) under different reaction conditions. The mechanism by which Grubbs 1st and 2nd generation catalysts mediate olefin metathesis has been studied, little is known regarding the mechanism of ATRP reaction promoted by these complexes. Conversion and semilogarithmic kinetic plots as a function of time were correlated to the different catalysts and reaction conditions; especially in the presence of Al(OiPr)3 as additive. Molecular weight (Mn) and polydispersity index (PDI) values changed with different catalysts in the presence or absence of Al(OiPr)3. Kinetic studies by 1H NMR revealed that two complexes in the presence of Al(OiPr)3 are converted into ATRP-active with the dissociation of PCy3, but with the benzylidene group preserved. More controlled polymerizations were achieved using Grubbs 1st and, the presence of Al(OiPr)3 improved the control levels for both catalysts. (AU)

• Processo FAPESP: 13/10002-0 - Desenvolvimento de complexos de rutênio como sistemas catalíticos duais na polimerização simultânea ROMP/ATRP
• Beneficiário: Valdemiro Pereira de Carvalho Júnior
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores