Synthesis and barrier properties of poly(ε‐caprolactone)‐layered silicate nanocomposites
01 May 1995-Journal of Polymer Science Part A (John Wiley & Sons Inc.)-Vol. 33, Iss: 7, pp 1047-1057
TL;DR: In this article, a polymer-ceramic nanocomposite was synthesized consisting of well-dispersed, two-dimensional layers of an organically modified mica-type silicate (MTS) within a degradable poly(e-caprolactone) matrix.
Abstract: A new polymer-ceramic nanocomposite has been synthesized consisting of well-dispersed, two-dimensional layers of an organically modified mica-type silicate (MTS) within a degradable poly(e-caprolactone) matrix. A protonated amino acid derivative of MTS was used to promote delamination/dispersion of the host layers and initiate ring-opening polymerization of e-caprolactone monomer, resulting in poly(e-caprolactone) chains that are ionically bound to the silicate layers. The polymer chains can be released from the silicate surface by a reverse ion-exchange reaction and were shown to be spectroscopically similar to pure poly(e-caprolactone). Thick films of the polymer nanocomposite exhibit a significant reduction in water vapor permeability that shows a linear dependence on silicate content. The permeability of nanocomposite containing as low as 4.8% silicate by volume was reduced by nearly an order of magnitude compared to pure poly(e-caprolactone)
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TL;DR: A review of the academic and industrial aspects of the preparation, characterization, materials properties, crystallization behavior, melt rheology, and processing of polymer/layered silicate nanocomposites is given in this article.
6,343 citations
TL;DR: In this article, a review of polymer-layered silicate nanocomposites is presented, where the polymer chains are sandwiched in between silicate layers and exfoliated layers are more or less uniformly dispersed in the polymer matrix.
Abstract: This review aims at reporting on very recent developments in syntheses, properties and (future) applications of polymer-layered silicate nanocomposites. This new type of materials, based on smectite clays usually rendered hydrophobic through ionic exchange of the sodium interlayer cation with an onium cation, may be prepared via various synthetic routes comprising exfoliation adsorption, in situ intercalative polymerization and melt intercalation. The whole range of polymer matrices is covered, i.e. thermoplastics, thermosets and elastomers. Two types of structure may be obtained, namely intercalated nanocomposites where the polymer chains are sandwiched in between silicate layers and exfoliated nanocomposites where the separated, individual silicate layers are more or less uniformly dispersed in the polymer matrix. This new family of materials exhibits enhanced properties at very low filler level, usually inferior to 5 wt.%, such as increased Young’s modulus and storage modulus, increase in thermal stability and gas barrier properties and good flame retardancy.
5,901 citations
TL;DR: In this paper, a new, versatile and environmentally benign synthesis approach by polymer melt intercalation is discussed. But, unlike in-situ polymerization and solution inter-calation, melt interalation involves mixing the layered silicates with the polymer and heating the mixture above the softening point of the polymer.
Abstract: Polymer nanocomposites with layered silicates as the inorganic phase (reinforcement) are discussed. The materials design and synthesis rely on the ability of layered silicates to intercalate in the galleries between their layers a wide range of monomers and polymers. Special emphasis is placed on a new, versatile and environmentally benign synthesis approach by polymer melt intercalation. In contrast to in-situ polymerization and solution intercalation, melt intercalation involves mixing the layered silicate with the polymer and heating the mixture above the softening point of the polymer. Compatibility with various polymers is accomplished by derivatizing the silicates with alkyl ammonium cations via an ion exchange reaction. By fine-tuning the surface characteristics nanodispersion (i. e. intercalation or delamination) can be accomplished. The resulting polymer layered silicate (PLS) nanocomposites exhibit properties dramatically different from their more conventional counterparts. For example, PLS nanocomposites can attain a particular degree of stiffness, strength and barrier properties with far less inorganic content than comparable glass- or mineral reinforced polymers and, therefore, they are far lighter in weight. In addition, PLS nanocomposites exhibit significant increase in thermal stability as well as self-extinguishing characteristics. The combination of improved properties, convenient processing and low cost has already led to a few commercial applications with more currently under development.
3,468 citations
TL;DR: An overview of polymer-clay hybrid nanocomposites is provided with emphasis placed on the use of alkylammonium exchanged smectite clays as the reinforcement phase in selected polymer matrices as discussed by the authors.
2,403 citations
Cites background from "Synthesis and barrier properties of..."
...Messersmith and Giannelis, 1995 ....
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...Relative permeability P rP vs. volume fraction of clay for poly ´-caprolactone –c o Ž .montmorillonite nanocomposites Messersmith and Giannelis, 1995 ....
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TL;DR: In this paper, the structure, preparation and properties of polymer-layered silicate nanocomposites are discussed in general, and detailed examples are also drawn from the scientific literature.
2,277 citations