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https://hdl.handle.net/1822/15318
Título: | Multi scale structure evolution of pet/mmt and PET/SiO2 nanocomposites upon solid state uniaxial deformation : an in situ WAXS/SAXS study |
Autor(es): | Martins, Carla I. Viana, J. C. Todorov, Lyudmil V. |
Palavras-chave: | Nanoclay Nano silica x-ray diffraction |
Data: | 2011 |
Editora: | Nepal Polymer Institute |
Resumo(s): | This work reports an investigation on the solid state uniaxial deformation of neat poly(ethylene terephthalate), PET, and its nanocomposites with montmorillonite, MMT, and nanosilica, SiO2, followed by in situ WAXS/SAXS (under X-ray synchrotron source radiation). The nanocomposites were produced via direct melt blending with addition of 0.3wt% of nanoparticles. Structural characterization by TEM revealed relatively good dispersion of both types nanofillers, namely intercalated morphology for the PET/MMT nanocomposite and agglomerate sizes (c.a. 80 nm) for the PET/ SiO2 nanocomposites. Despite the type of nanoreinforcements, three common stages of multiscale structure evolution were indentified: - Stage I, before necking, is characterized by a small amount of amorphous phase evolving into mesophase at almost constant molecular orientation level; - Stage II, at neck propagation, where a rapid increase of polymer molecular orientation is accompanied by a sharp increase of the mesophase and by the formation of a periodical mesophase; it is also observed the appearance of crazes in the polymer matrix, and voids within the nanoparticles agglomerates 1-4. - Stage III, during necking, corresponds to the transformation of crazes and voids into micro-voids, at a plateau of average molecular orientation. The highest periodical mesophase content is achieved together with a slight increment of mesophase1-4. In comparison to the neat PET structure evolution, all kind of nanocomposites showed: i) improved amount of mesophase and maximum periodical mesophase formed at earlier deformations; ii) retarded crazes widening/growing within the polymer bulk, and iii) similar maximum orientation level are achieved. Multiscale structures modelling are suggested based on the results obtained. |
Tipo: | Resumo em ata de conferência |
URI: | https://hdl.handle.net/1822/15318 |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | IPC - Resumos em actas de encontros científicos internacionais com arbitragem |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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abstractpolychar19_Carla Martins.pdf Acesso restrito! | documento principal | 108,78 kB | Adobe PDF | Ver/Abrir |