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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Laponite (R)-based colloidal nanocomposites prepared by RAFT-mediated surfactant-free emulsion polymerization: the role of non-ionic and anionic macroRAFT polymers in stability and morphology control

Texto completo
Autor(es):
Chaparro, Thaissa C. [1, 2, 3] ; Silva, Rodrigo D. [1, 4] ; Dugas, Pierre-Yves [2] ; D'Agosto, Franck [2] ; Lansalot, Muriel [2] ; Martins dos Santos, Amilton [1] ; Bourgeat-Lami, Elodie [2]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Engn Sch Lorena, BR-12602810 Lorena, SP - Brazil
[2] Univ Lyon, Univ Claude Bernard Lyon 1, Chem Catalysis Polymers & Proc C2P2, CNRS, CPE Lyon, UMR 5265, 43, Blvd 11 Novembre 1918, F-69616 Villeurbanne - France
[3] Univ Bordeaux, CNRS, Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac - France
[4] Ctr Univ Formiga, 328 Doutor Arnaldo Senna Ave, BR-35574530 Formiga, MG - Brazil
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: Polymer Chemistry; v. 12, n. 1, p. 69-81, JAN 7 2021.
Citações Web of Science: 2
Resumo

The synthesis of Laponite (R)-based composite latexes by reversible addition-fragmentation chain transfer (RAFT)-mediated surfactant-free emulsion polymerization is described. RAFT homopolymers and copolymers (macroRAFT agents) comprising acrylic acid (AA), poly(ethylene glycol) (PEG) segments and n-butyl acrylate (BA) repeating units were adsorbed onto exfoliated Laponite (R) in aqueous dispersion, and subsequently chain extended by methyl methacrylate and BA to form colloidal nanocomposites. The high hydrophilicity of PAA macroRAFT agents led to unstable latexes as polymerization took place mainly in the aqueous phase. Differently, PEG-based RAFT copolymers adsorbed more strongly onto Laponite (R) and favored morphology control. The free macroRAFT chains engaged preferably in the stabilization of the hybrid structures, rather than in the formation of free latex particles, resulting primarily in a Janus morphology. The presence of BA units in the macroRAFT structure helped further in confining the polymerization on the clay surface and enabled the morphology of the particles to be tuned resulting in the formation of dumbbell or sandwich-like structures. These results show that the parameters driving the competing mechanisms related to the polymerization locus, such as the presence of free macroRAFTs, the affinity between macroRAFTs and clay and the adequate hydrophilic-hydrophobic balance within the macroRAFT structure, are key for assuring both the stabilization of the nanocomposite particles and the control of their morphology. (AU)

Processo FAPESP: 10/19919-6 - Síntese de nanocompósitos com propriedades anisotrópicas via polimerização radicalar controlada em emulsão
Beneficiário:Thaíssa de Camargo Chaparro
Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
Processo FAPESP: 10/50383-5 - Polymer-encapsulation of anisotropic inorganic particles by raft-mediated emulsion polymerization
Beneficiário:Amilton Martins dos Santos
Modalidade de apoio: Auxílio à Pesquisa - Regular
Processo FAPESP: 11/20533-8 - Encapsulação de montmorilonita via polimerização radicalar controlada do tipo RAFT em emulsão para produção de filmes nanoestruturados com propriedades anisotrópicas
Beneficiário:Rodrigo Duarte Silva
Modalidade de apoio: Bolsas no Brasil - Doutorado