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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.)

Effect of exfoliation medium on the morphology of multi-layer graphene oxide and its importance for Poly(Ethylene terephthalate) based nanocomposites

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Autor(es):
Pinto, Gabriel M. [1] ; Silva, Giovanna da C. [1] ; Fechine, Guilhermino J. M. [1]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Prebiteriana Mackenzie, Mackenzie Inst Res Graphene & Nanotechnol MackGra, Rua Consolacao 896, BR-01302907 Sao Paulo, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: Polymer Testing; v. 90, OCT 2020.
Citações Web of Science: 1
Resumo

Poly(ethylene terephthalate) (PET)/multi-layer graphene oxide (mGO) nanocomposites were produced using the melt compounding technique, with the aid of a twin-screw extruder. The main goal was to investigate the effect of different exfoliation media on the morphology of graphene oxide and its effects, mainly on the mechanical performance of PET/mGO based polymer nanocomposites. Two different exfoliation media (water and ethanol) were used for the mGO synthesis. Based on each medium, nanocomposites with three different mGO contents (0.05 wt%, 0.1 wt%, and 0.3 wt%) were produced. When exfoliated in water, mGO sheets present larger lateral dimensions, i.e., higher surface area available to interact with polymer chains. All nanocomposites presented similar crystallinity, but with a slight increase related to the neat PET, indicating the nucleating effect of mGO. A theoretical model was used to predict the nanocomposites elastic modulus, justifying the experimental results. The biggest mechanical improvement was presented by a composite with low content of water-exfoliated mGO (0.1 wt%). The polymer tensile strength, strain at break, and toughness were improved by 19%, 238% and 590%, respectively. A significant reduction in the polymer dissipation factor (Milo) with mGO content was also verified, indicating some confinement of polymeric chains due to interactions with the mGO sheets. The different surface fracture mechanisms presented by the nanocomposite with 0.1 wt% water-exfoliated mGO were verified, in which a good interface allowed greater release of strain energy. The XR-MT data confirmed that differences in mGO morphology can sensitively affect the final composite properties, characterising it as the driving force for mechanical improvements. Therefore, a melt compounded PET/graphene derivative composite is presented, exhibiting more promising results than what is already reported by solution mixed and in-situ polymerised composites. It was possible due to the strategic processing route utilised, in which the exfoliated mGO was premixed with the polymer powder using the SSD technique. (AU)

Processo FAPESP: 18/18055-0 - Investigação das propriedades de barreira de nanocompósitos PET/GO para a indústria de embalagens
Beneficiário:Giovanna da Cruz Silva
Linha de fomento: Bolsas no Brasil - Iniciação Científica
Processo FAPESP: 18/10910-8 - Fotodegradação e fotoestabilização de nanocompósitos poliméricos a base de cargas bidimensionais
Beneficiário:Guilhermino José Macêdo Fechine
Linha de fomento: Auxílio à Pesquisa - Regular
Processo FAPESP: 18/05440-2 - Propriedades mecânicas e de barreira de nanocompósitos formados por politerftalato de etileno e óxido de grafeno (PET/GO)
Beneficiário:Gabriel Matheus Pinto
Linha de fomento: Bolsas no Brasil - Mestrado
Processo FAPESP: 12/50259-8 - Grafeno: fotônica e opto-eletrônica: colaboração UPM-NUS
Beneficiário:Antonio Helio de Castro Neto
Linha de fomento: Auxílio à Pesquisa - Programa SPEC