Please use this identifier to cite or link to this item: http://hdl.handle.net/10773/19673
Title: Studies on PLA grafting onto graphene oxide and its effect on the ensuing composite films
Author: Campos, Joao M.
Ferraria, Ana M.
Botelho do Rego, Ana M.
Rosario Ribeiro, M.
Barros-Timmons, Ana
Keywords: RING-OPENING POLYMERIZATION
POLY-LACTIC-ACID
EXFOLIATED GRAPHITE OXIDE
CLICK CHEMISTRY
CRYSTALLIZATION KINETICS
POLY(LACTIC ACID)
MECHANICAL-PROPERTIES
ALIPHATIC POLYESTERS
NANOCOMPOSITES
SHEETS
Issue Date: 2015
Publisher: ELSEVIER SCIENCE SA
Abstract: Polylactide (PLA) with a terminal triple bond was synthesized by organocatalyzed ring-opening polymerization and coupled with azide-functionalized graphene oxide (GO) through an azide-alkyne cycloaddition \"click\" reaction. The functionalized graphenic species involved were analyzed by spectroscopic techniques (FT-IR, solid state C-13 NMR, Raman), which confirmed the coupling of PLA and GO. Additionally, an in depth study of the prepared GO, intermediates and GO-g-PLA hybrid was carried out that sheds light on the mechanisms involved in the functionalization path. The obtained GO-g-PLA hybrid, containing at least 20% of biopolymer, presented an exfoliated graphenic structure, as established by XRD. The conditions used in the grafting of the PIA chains inhibited the crystallization and melting observed for the free polymer. Furthermore, the graphene oxide seems to be reduced during functionalization, which can also be an advantage. Nanocomposites were obtained as solvent-cast films, prepared by dispersion of the GO-g-PLA hybrid in commercial PEA. Preliminary results regarding the performance of these nanocomposites, obtained by DSC and DMA, highlighted the effect of functionalization. Loading values as low as 0.5% suffice to improve the mechanical properties over a broad temperature range due to the high surface area resulting from the good dispersibility of polymer functionalized nanofillers and/or their effect on the polymer chain organization. (C) 2015 Elsevier B.V. All rights reserved.
Peer review: yes
URI: http://hdl.handle.net/10773/19673
DOI: 10.1016/j.matchemphys.2015.09.036
ISSN: 0254-0584
Publisher Version: 10.1016/j.matchemphys.2015.09.036
Appears in Collections:CICECO - Artigos



FacebookTwitterLinkedIn
Formato BibTex MendeleyEndnote Degois 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.