Effect of organic modification on the intercalation and the properties of poly(phenylene oxide)/ polystyrene blend-clay nanocomposites
01 Apr 2013-Journal of Thermoplastic Composite Materials (SAGE Publications)-Vol. 26, Iss: 3, pp 392-415
TL;DR: In this article, nanocomposites prepared by the dispersion of unmodified and organically modified montmorillonite (MMT) clay into poly(2,6-dimethyl phenylene oxide)/polystyrene miscible blend in the range of 2-10% clay were investigated by wide-angle x-ray diffraction, transmission electron microscopy, differential scanning calorimetry, thermogravimetric analysis and tensile mechanical tests.
Abstract: Nanocomposites prepared by the dispersion of unmodified and organically modified montmorillonite (MMT) clay into poly(2,6-dimethyl phenylene oxide)/polystyrene miscible blend in the range of 2–10 wt% clay were investigated by wide-angle x-ray diffraction, transmission electron microscopy, differential scanning calorimetry, thermogravimetric analysis and tensile mechanical tests. The systems based on unmodified sodium MMT (Na+MMT) as well as Cloisite 20A, Cloisite 30B and Cloisite 10A organically modified clays showed polymer intercalation. The glass transition temperature (Tg) value was not affected by the volume fraction of clay and chemical nature of the organoclay. The thermal degradation stability of nanocomposites is found to be only slightly better than that of the blend matrix. A percolation threshold of around 4 wt% organoclay loading is observed. An improvement of 35% relative to unfilled polymer blend matrix is observed for the modulus, for Cloisite 20A nanocomposite containing 2 wt% organoclay....
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TL;DR: In this article, the effect of Laponite (a synthetic clay) on the structure, thermal and water vapor barrier properties of nanocomposite gelatin films produced by casting with 0, 4.5 and 15% w Lap/w gelatin was studied.
Abstract: The effect of Laponite® (a synthetic clay) on the structure, thermal and water vapor barrier properties of nanocomposite gelatin films produced by casting with 0, 4.5 and 15% w Lap/w gelatin, was studied. X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy measurements were reported. The X-ray diffraction patterns showed dual crystalline structure of the films with collagen-type bundles of triple helices, intercalated inside clay platelets, increasing interlayer distances. Depending on the renaturation of triple-helices and Laponite content, the glass transition temperatures substantially decreased. The amount of helices decreased with Lap concentration, affecting the enthalpy of melting. The nanocomposite gelatin films showed improved thermal stability. Changes of water vapor permeability could be related to the presence of a larger free volume of the coils and intercalated structures, facilitating water transfer through the film.
26 citations
TL;DR: In this article, organoclay-containing polystyrene (PS)-based nanocomposites were fabricated by extrusion in the presence of thermoplastic elastomer modifiers.
Abstract: In this study, organoclay-containing polystyrene (PS)-based nanocomposites were fabricated by extrusion in the presence of thermoplastic elastomer modifiers. Styrene–butadiene–styrene (SBS) rubber ...
11 citations
TL;DR: In this article, a polymer/clay (nano)composites, based on poly(acrylic acid) (PAA) and poly(ACrylic acid co-styrene) poly(AA-co-St), were synthesized by free radical polymerization, using 2,2′-azobis(isobutyronitrile) (AIBN), as initiator and organomodified clay (OMMT), as nanofillers.
Abstract: In this contribution, polymer/clay (nano)composites, based on poly(acrylic acid) (PAA) and poly(acrylic acid-co-styrene) poly(AA-co-St), were synthesized by free radical polymerization, using 2,2′-azobis(isobutyronitrile) (AIBN), as initiator and organomodified clay (OMMT), as nanofillers. The structural and morphological characteristics of the obtained (nano)composites, PAA/OMMT (1, 3, 5 wt%), poly(AA75-co-St25)/OMMT (3 wt%) and poly(AA25-co-St75)/OMMT (3 wt%), were examined by X-ray diffraction and scanning electron microscopy, indicating the successful intercalation of polymer chains into the clay nanoplatelets. Thermal properties of obtained (nano)composites were evaluated according to thermogravimetric analysis and differential scanning calorimetry. Based on morphological and thermal results, poly(AA25-co-St75)/OMMT (3 wt%) (nano)composite was selected as an efficient adsorbent matrix for methylene blue dye, with about 74% of elimination obtained after only 80 min of swelling, under soft conditions.
6 citations
TL;DR: In this paper, the effect of Laponite (a synthetic clay) on the structure, thermal and water vapor barrier properties of nanocomposite gelatin films produced by casting with 0, 4.5 and 15% w Lap/w gelatin, was studied.
Abstract: The effect of Laponite (a synthetic clay) on the structure, thermal and water vapor barrier properties of nanocomposite gelatin films produced by casting with 0, 4.5 and 15% w Lap/w gelatin, was studied. X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy measurements were reported. The X-ray diffraction patterns showed dual crystalline structure of the films with collagen-type bundles of triple helices, intercalated inside clay platelets, increasing interlayer distances. Depending on the renaturation of triple-helices and Laponite content, the glass transition temperatures substantially decreased. The amount of helices decreased with Lap concentration, affecting the enthalpy of melting. The nanocomposite gelatin films showed improved thermal stability. Changes of water vapor permeability could be related to the presence of larger free volume of the coils and intercalated structures, facilitating water transfer through the film.
5 citations
TL;DR: In this paper, the morphology and rheological behavior of poly(butylene terephthalate)/polypropylene (PBT/PP) blends containing hydrophilic and hydrophobic organoclays were investigated.
Abstract: The present research investigates the morphology and rheological behavior of poly(butylene terephthalate)/polypropylene (PBT/PP) blends containing hydrophilic and hydrophobic organoclays. The distr...
5 citations
References
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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
"Effect of organic modification on t..." refers methods in this paper
...Intercalated and exfoliated nanocomposites show enhancement of polymer matrix properties.(1,2,4,5) Melt-processing or melt-mixing method is a viable and versatile method for nanocomposite preparation....
[...]
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
"Effect of organic modification on t..." refers methods in this paper
...Intercalated and exfoliated nanocomposites show enhancement of polymer matrix properties.(1,2,4,5) Melt-processing or melt-mixing method is a viable and versatile method for nanocomposite preparation....
[...]
TL;DR: In this article, the static and dynamic properties of polymer-layered silicate nanocomposites are discussed, in the context of polymers in confined spaces and polymer brushes.
Abstract: The static and dynamic properties of polymer-layered silicate nanocomposites are discussed, in the context of polymers in confined spaces and polymer brushes. A wide range of experimental techniques as applied to these systems are reviewed, and the salient results from these are compared with a mean field thermodynamic model and non-equilibrium molecular dynamics simulations.
1,096 citations
TL;DR: In this paper, the effect of silicate functionalization, anneal temperature, polymer molecular weight, and constituent interactions on polymer melt intercalation of a variety of styrene-derivative polymers in alkylammonium-functionalized silicates is examined.
Abstract: The effect of silicate functionalization, anneal temperature, polymer molecular weight, and constituent interactions on polymer melt intercalation of a variety of styrene-derivative polymers in alkylammonium-functionalized silicates is examined. Hybrid formation requires an optimal interlayer structure for the organically-modified layered silicate (OLS), with respect to the number per host area and size of the alkylammonium chains, as well as the presence of polar interactions between the OLS and polymer. From these observations and the qualitative predictions of the mean-field lattice-based model of polymer melt intercalation (preceding paper in this issue), general guidelines may be established for selecting potentially compatible polymer−OLS systems. The interlayer structure of the OLS should be optimized to maximize the configurational freedom of the functionalizing chains upon layer separation while maximizing potential interaction sites with the surface. The most successful polymers for intercalatio...
976 citations