Poly montmorillonite composites

Electrical properties have been reported on numerous carbon fiber-reinforced polymers, including carbon nanoflber-modified thermotropic liquid crystalline polymers [53], low-density polyethylene [54], ethylene vinyl acetate [55], wire coating varnishes [56], polydimethyl siloxane polypyrrole composites [50], polyacrylonitrile [59], polycarbonate [58], polyacrylonitrile-polycarbonate composites [58], modified chrome polymers [59], lithium trifluoromethane sulfonamide-doped polystyrene-block copolymer [60], boron-containing polyvinyl alcohols [71], lanthanum tetrafluoride complexed ethylene oxide [151, 72, 73], polycarbonate-acrylonitrile diene [44], polyethylene deoxythiophe-nel, blends of polystyrene sulfonate, polyvinyl chloride and polyethylene oxide [43], poly-pyrrole [61], polypyrrole-polypropylene-montmorillonite composites [62], polydimethyl siloxane-polypyrrole composites [63], polyaniline [46], epoxy resin-polyaniline dodecyl benzene sulfonic acid blends [64], and polyaniline-polyamide 6 composites [49]. 

Cao, D. and Heimann, R.B. (1993) Structure and mechanical properties of superabsorbent poly(acrylamide)-montmorillonite composite hydrogels. Polym. Gels Networks, 1, 225-246. 

PP-g-MA) silicate nanocomposites and intercalated thermoset silicate nanocomposites for flame-retardant applications were characterised by XRD and TEM [333], XRD, TEM and FTIR were also used in the study of ID CdS nanoparticle-poly(vinyl acetate) nanorod composites prepared by hydrothermal polymerisation and simultaneous sulfidation [334], The CdS nanoparticles were well dispersed in the polymer nanorods. The intercalation of polyaniline (PANI)-DDBSA (dodecylbenzene-sulfonate) into the galleries of organo-montmorillonite (MMT) was confirmed by XRD, and significantly large 4-spacing expansions (13.3-29.6A) were observed for the nanocomposites [335],... 

F. Bignotti, L. Sartore, M. Penco, G. Ramorino, and I. Peroni, Effect of montmorillonite on the properties of thermosensitive poly(N-isopropylacrylamide) composite hydrogels, J. Appl. Polym. Sci., 93, 1964-1971 (2004). 

Abstract. The review aims at highlighting the significant developments in the field of poly-mer-montmorillonite clay based nanocomposites with specific focus on synthetic methodologies used, characterization, and evaluation of relevant bulk properties of these composites. 

Kaczmarek, H., Podgorski, A. J. Photochem. Photobiol. A The effect of UV-irradiation on poly(vinyl alcohol) composites with montmorillonite. Journal of Photochemistry and Photobiology. Journal of Photochemistry and Photobiology. Chemi. 191, 209-215 (2007)... 

In practice, the techniques of blending, compositing and nano-reinforcement are often used together. Thermoplastic starch/poly(vinyl alcohol) (PVOH)/clay nanocomposites exhibited the intercalated and exfoliated structures [260]. Mont-morillonite (MMT) with three types of cation or modifier (Na", alkyl ammonium ion, and citric acid) was examined. The prepared nanocomposites with modified montmorillonite indicated a mechanical improvement in the properties, in comparison with pristine MMT. 

Recently, in our group, we evaluated the potentiality of a poly(iniide) (PI)/ organically-modified montmorillonite (O-MMT) nanocomposite membrane for the use in alkaline fuel cells [73]. Both X-ray diffraction and scanning electron microscopy revealed a good dispersion of O-MMT into the PI matrix and preservation of the O-MMT layered structure. When compared to the pure PI, the addition of O-MMT improved thermal stability and markedly increased the capability of absorbing electrolyte and ionic conductivity of the composite. Based on these results, the PI/ O-MMT nanocomposite is a promising candidate for alkaline fuel cell appUcations. 

Yang CC (2011) Fabrication and characterization of poly(vinyl alcohol)/montmorillonite/ poly(styrene sulfonic acid) proton-conducting composite membranes for direct methanol fuel cells. Int J Hydrogen Energ 36 4419 431... 

Sodium montmorillonite can also be used to polymerize polar monomers between the lamellae. Here too, the organization of monomer molecules within the monolayers influences the structure of the resultant polymers [212, 213]. Poly(methyl methacrylate) formed in sodium montmorillonite is composed of short, predominantly isotactic stereosequences [211]. The percentage of isotactic component increases with an increase in the ion exchanging population on the surface of the mineral and is independent of the temperature between 20 and 160°C. In this way, it is possible to vary the population of isotactic triads at will up to 50% composition [205]. 

Sumita M, Tsukumo Y, Miyasaka K et al (1983) Tensile yield stress of polypropylene composites filled with ultrafine particles. J Mater Sci 18 1758—1764 Thellen C, Orroth C, Froio D et al (2005) Influence of montmorillonite layered silicate on plasticized poly(l-lactide) blown films. Polymer 46 1716-11727 Uyama H, Kuwabara M, Tsujimoto T et al (2003) Green nanocomposites from renewable resources plant oil-clay hybrid materials. Chem Mater 15 2492-2494 Wang SF, Shen L, Zhang WD et al (2005a) Preparation and mechanical properties of chitosan/ carhon nanotuhes composites. Biomactomolecules 6 3067—3072... 

Oyama et al. [92, 93] conducted admittance measurements of a montmoril-lonite clay film and a montmorillonite clay/poly(vinyl alcohol) composite film in various concentrations of Na2S04. A drastic change in the equivalent circuit resistance was observed at the concentration of ca. 0.2-0.3 M, and was attributed to a structural change in the clay film from a face-to-face structure in a higher concentration to an edge-to-face structure in a lower concenhation. The latter structure is considered to be relatively flexible, swollen and viscoelastic, and therefore, acts as a resistance to the oscillation. In the case of the clay/PVP composite fihn, the motion freedom of the individual clay platelets... 

Poly(vinyl alcohol) has also been shown to provide mechanically adaptive properties to composite films comprised of a PVOH electrospun mat and a PVAc or EO-EPI matrix. Films made from such composites exhibited controlled response to hydration that resulted in a two fold decrease of the storage modulus which, in the case of the PVAc composite, was fully reversible. Expanding on this concept and in a similar motif to the aforementioned CNC composites, Korley and coworkers have recently showcased the potential use of montmorillonite in mechanically adaptive composite materials. Montmorillonite is a layered silicate with high aspect ratio and surface area and is often used in polymer composites to mechanically reinforce the resulting material, while its dispersibility and tunable surface chemistiy make its use particularly attractive. In this case, the incorporation of montmorillonite in the PVOH fibrous filler resulted in enhanced moduli when the polymer matrix consisted of EO-EPI, as opposed to the limited enhancement observed in the case of a PVAc matrix. Nonetheless, both composites showed mechanically switching properties upon hydration, with the weight fraction of montmorillonite affecting the mechanical contrast as well as the response time. ... 

Montmorillonites / poly(N-isopropyl acrylamide) [16] Norfloxacin Semi-interpenetrated network hydrogels Allows multiresposive drug delivery systems. Norfloxacin release controlled by the presence of montmorillonite nanoparticles and by the viscosity of swollen hybrid hydrogels. Formulations of the hybrid network with Dellite 67 G. nanoparticles showed a better sustained release than that of composites with Dellite HPS and a better balance between the relaxation time and the amount of released drug. 

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