Influence of annealing-induced phase separation on the shape memory effect of graphene-based thermoplastic polyurethane nanocomposites
Tipo
Artigo
Data de publicação
2024
Periódico
Journal of Applied Polymer Science
Citações (Scopus)
2
Autores
Valim F.C.F.
Oliveira G.P.
de Paiva L.B.
Amurin L.G.
Santillo C.
Lavorgna M.
Andrade R.J.E.
Oliveira G.P.
de Paiva L.B.
Amurin L.G.
Santillo C.
Lavorgna M.
Andrade R.J.E.
Orientador
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
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Resumo
© 2023 Wiley Periodicals LLC.Thermoplastic polyurethane (TPU) is a multiblock copolymer that exhibits an attractive shape memory effect (SME). Its morphology consists of a soft segment (SS), which corresponds to the polyol or a long-chain diol, while the hard segment involves the intercalation of a diisocyanate and a chain extender. Due to the distinct thermodynamic parameters of each monomer, these segments are not miscible with each other, resulting in a phase-separated structure in their morphology. This structure is characterized by the formation of soft and hard domains (SD and HD), respectively. When incorporating 0.1 wt% of graphene nanoplatelets (GNP) or 0.1 wt% of multilayer graphene oxide (mGO) into the TPU matrix using solution casting process, a contribution to the phase separation of these domains is observed. This phenomenon becomes even more pronounced when graphene-based nanocomposites are subjected to annealing at 110°C for 24 hours, indicating a good interaction between the GO and GNP with the HD and SS, respectively. After annealing, the nanocomposites (TPU + GNP and TPU + mGO) exhibit improved performance in SME, as evidenced by an approximately 9% increase in the shape recovery ratio compared to the nonannealed TPU. Additionally, all nanocomposites maintained a high strain during SME programming, surpassing that of pure TPU, both before and after annealing. This suggests a direct influence of the graphene-based nanoparticles on the shape memory effect.
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Assuntos Scopus
Graphene nanoplatelets , Graphene oxides , Long chains , Multiblock copolymer , Multilayer graphene , Shape-memory , Shape-memory effect , Soft segments , Thermoplastic polyurethane nanocomposites , Thermoplastic polyurethanes