Combining CROP and ATRP to synthesize pH-responsive poly(2-ethyl-2-oxazoline-b-4-vinylpyridine) block copolymers

Autor(es)

Lima de Menezes, Rafael Natal ^[1] ; Felisberti, Maria Isabel ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, R Josue de Castro, POB 6154, BR-13084971 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Polymer Chemistry; v. 12, n. 32 JUL 2021.
• Citações Web of Science: 0

Resumo

Herein, we present the synthesis and characterization of block copolymers based on poly(2-ethyl-2-oxazoline), a biocompatible and stealth polymer that has drawn considerable attention in biomedical-related applications, and poly(4-vinylpyridine), a polydentate ligand and pH-responsive polymer, with interesting characteristics for application as optical, magnetic, electronic, catalytic and conductive materials, as well as in the biomedical field. Poly(2-ethyl-2-oxazoline-b-4-vinylpyridine) block copolymers were synthesized by the cationic ring-opening polymerization (CROP) of 2-ethyl-2-oxazoline (EtOx) followed by atom transfer radical polymerization (ATRP) of 4-vinylpyridine (4VP). P(EtOx-b-4VP) polymers with 4VP molar fractions ranging from 0.40 to 0.71 were obtained. These polymers presented a narrow molar mass dispersity (approximate to 1.2) and molar mass in the range of 6.4-10.5 kDa. The thermal properties of P(EtOx-b-4VP) were evaluated by differential scanning calorimetry (DSC) and their implication in the self-assembly in solution is discussed. The critical micellar concentration in water was determined by fluorescence spectroscopy and the self-assembly of P(EtOx-b-4VP) in water/DMF and basic aqueous solutions was studied by turbidimetry and dynamic light scattering (DLS). The morphology of the resulting structures was assessed by cryogenic transmission electron microscopy (cryo-TEM). Depending on the composition of polymer and solution, different structures, namely micelles, vesicles and worm-like micelles, can be formed. Concerning the interesting properties of PEtOx (stealth behavior and biocompatibility), as well as P4VP (pH-responsive polydentate ligand), these materials show potential for application in drug delivery, diagnostic imaging and as templates for inorganic materials. (AU)

• Processo FAPESP: 15/25406-5 - Organizando a matéria: colóides formados por associação de surfactantes, polímeros e nanopartículas
• Beneficiário: Watson Loh
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/16615-5 - Síntese e caracterização de cápsulas poliméricas responsivas
• Beneficiário: Rafael Natal Lima de Menezes
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto