Studies on poly(vinylidene fluoride)–clay nanocomposites: effect of different clay modifiers
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Title |
Studies on poly(vinylidene fluoride)–clay nanocomposites: effect of different clay modifiers
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Creator |
PATRO, TU
MHALGI, MILIND V KHAKHAR, DV MISRA, ASHOK |
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Subject |
organoclay
pvdf nanocomposite |
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Description |
Montmorillonite clay based poly(vinylidene fluoride) nanocomposites were prepared by melt-mixing. The clays used included unmodified clay, a commercially available ammonium based clay, and two organically modified clays prepared by cation exchange with hexadecylpyridinium chloride and with octadecyltriphenylphosphonium bromide. PVDF–clay nanocomposites were processed in a mini twin-screw extruder. The structure of nanocomposites, analyzed using WAXD and TEM, indicated different extents of the clay dispersion depending on the modifier. PVDF formed β-phase crystals in the presence of organically modified clay when crystallized from its melt; in contrast, α-crystals were formed in the absence of clay and with unmodified clay. SAXS analysis indicated that the long period and crystalline lamella thickness decreased with the addition of clay. The melting and crystallization temperatures increased around 10 and 13 °C, respectively, with 5 wt% of phosphonium modified clay, which was the highest among the clays used. Further, the clay served as a nucleating agent for PVDF matrix, as observed by hot-stage polarized optical microscopy. The average spherulitic radius, determined from small angle light scattering, decreased with clay content. The elongation at break increased around 200% with the addition of only 5 wt% of ammonium clay. The storage and loss moduli of the nanocomposites were significantly higher than those of PVDF throughout the temperature range. Dielectric measurements showed a maximum increase of about 8 units of dielectric constant at 1 Hz frequency with 5 wt% organoclay.
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Publisher |
Elsevier
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Date |
2009-03-05T08:22:57Z
2011-11-25T18:32:39Z 2011-12-26T13:07:05Z 2011-12-27T05:55:07Z 2009-03-05T08:22:57Z 2011-11-25T18:32:39Z 2011-12-26T13:07:05Z 2011-12-27T05:55:07Z 2008 |
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Type |
Article
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Identifier |
Polymer 49(16), 3486-3499
0032-3861 http://dx.doi.org/10.1016/j.polymer.2008.05.034 http://hdl.handle.net/10054/868 http://dspace.library.iitb.ac.in/xmlui/handle/10054/868 |
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Language |
en
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