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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.)

Synthesis and Self-Assembly of Poly(N-Vinylcaprolactam)-b-Poly(epsilon-Caprolactone) Block Copolymers via the Combination of RAFT/MADIX and Ring-Opening Polymerizations

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Autor(es):
Moraes, Rodolfo M. [1] ; Carvalho, Layde T. [1] ; Alves, Gizelda M. [1] ; Medeiros, Simone F. [1] ; Bourgeat-Lami, Elodie [2] ; Santos, Amilton M. [1]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Engn Sch Lorena, Dept Chem Engn, EEL USP, Lab Polymers, Estr Municipal do Campinho S-N, POB 116, BR-12602810 Lorena, SP - Brazil
[2] Univ Claude Bernard Lyon 1, Univ Lyon, CPE Lyon, CNRS, UMR 5265, Chem Catalysis Polymers & Proc C2P2, 43 Bvd 11 Novembre 1918, F-69616 Villeurbanne - France
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: POLYMERS; v. 12, n. 6 JUN 2020.
Citações Web of Science: 0
Resumo

Well-defined amphiphilic, biocompatible and partially biodegradable, thermo-responsive poly(N-vinylcaprolactam)-b-poly(epsilon-caprolactone) (PNVCL-b-PCL) block copolymers were synthesized by combining reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerizations (ROP). Poly(N-vinylcaprolactam) containing xanthate and hydroxyl end groups (X-PNVCL-OH) was first synthesized by RAFT/macromolecular design by the interchange of xanthates (RAFT/MADIX) polymerization of NVCL mediated by a chain transfer agent containing a hydroxyl function. The xanthate-end group was then removed from PNVCL by a radical-induced process. Finally, the hydroxyl end-capped PNVCL homopolymer was used as a macroinitiator in the ROP of epsilon-caprolactone (epsilon-CL) to obtain PNVCL-b-PCL block copolymers. These (co)polymers were characterized by Size Exclusion Chromatography (SEC), Fourier-Transform Infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance spectroscopy (H-1 NMR), UV-vis and Differential Scanning Calorimetry (DSC) measurements. The critical micelle concentration (CMC) of the block copolymers in aqueous solution measured by the fluorescence probe technique decreased with increasing the length of the hydrophobic block. However, dynamic light scattering (DLS) demonstrated that the size of the micelles increased with increasing the proportion of hydrophobic segments. The morphology observed by cryo-TEM demonstrated that the micelles have a pointed-oval-shape. UV-vis and DLS analyses showed that these block copolymers have a temperature-responsive behavior with a lower critical solution temperature (LCST) that could be tuned by varying the block copolymer composition. (AU)

Processo FAPESP: 13/03355-4 - Síntese de copolímeros em blocos biodegradáveis/biocompatíveis para a obtenção de micro e nanopartículas poliméricas para liberação controlada de drogas
Beneficiário:Rodolfo Minto de Moraes
Linha de fomento: Bolsas no Brasil - Doutorado Direto