Organic layered silicates

Mostly nanofilled PP is produced by injection molding however, composites prepared from iPP and sPP, respectively, and organic layered silicate by the spinning procedure have been reported. ... 

EVA/organic layered silicate nanocomposites can be also prepared by melt intercalation method. Alexandre and Dubois" found that nanocomposites were only formed when EVA was melt-blended at 1S0 C with nonfunctionalized organoclay, such as MMT exchanged with dimethyldioctadecyl ammonium. Zanetti et prepared EVA nanocomposites with fluorohectorite-like synthetic silicate exchanged with octadecylammonium and studied their thermal behaviors. 

A mixture of iron, ferric chloride and water is added to the toluene solution. The mixture is heated to reflux and concentrated hydrochloric acid is added dropwise at a rate calculated to keep the mixture refluxing vigorously. After the hydrochloric acid Is all added, the refluxing is continued by the application of heat for several hours. A siliceous filter aid is then added to the cooled reaction mixture and the material is removed by filtration. The filter cake is washed four times, each time with 90 ml of benzene. The organic layer is then separated from the filtrate. The water layer is acidified to a pH of 2 and extracted three times with 90 ml portions of benzene. 

Three main types of composites can be formed when the layered clay is incorporated with a polymer, as shown in Figure 2 (Alexandre and Dubois, 2000). Types of composites formed mostly depend on the nature of the components used (layered silicate, organic cation and polymer matrix) and the method of preparation. 

Since the possibility of direct melt intercalation was first demonstrated [11], melt intercalation has become a method of preparation of the intercalated polymer/ layered silicate nanocomposites (PLSNCs). This process involves annealing, statically or under shear, a mixture of the polymer and organically modified layered fillers (OMLFs) above the softening point of the polymer. During annealing, the polymer chains diffused from the bulk polymer melt into the nano-galleries between the layered fillers. 

Laird DA, Barriuso E, Dowdy RH, Koskinen WC (1992) Adsorption of atrazine on smectites. Soil Sci Soc Am J 56 62-67 LeBaron PC, Wang Z, Pinnavaia TJ (1999) Polymer-layered silicate nanocomposites an overview. Appl Clay Sci 15 11-29 Lee J-F, Crum JR, Boyd SA (1989) Enhanced retention of organic contaminants by soil exchanged with organic cations. Environ Sci Technol 23 1365-1372 Lee J-F, Mortland MM, Boyd SA, Chiou CT (1989a) Shape-selective adsorption of aromatic molecules from water by tetramethylammonium-smectite. J Chem Soc Faraday Trans I 8 2953-2962... 

Figure 6.3 Leaching of sensor layers M4, M1, M2 and M3 (from top) on exposure to a flow of buffer solution (left) and titration plots of AF in poly-TMOS (Ml), an organically modified silicate (M4), and covalently immobilized on ICPS (M2) and GOPS (M3) (right). (Reproduced from ref. 4, with permission.)...

Organic aerogels, 1 750-752 Organically modified layered silicate (OMLS), 20 306, 307, 308 Organic archaeological materials,... 

A. Weiss, Organic derivatives of mica-types layer silicates, Angew. Chem. Internat. Edit, vol. 2, pp. 134-143,1963. 

R. A. Vaia, E. P. Giannelis, Polymer melt intercalation in organically-modified layered silicates Model predictions and experiment, Macromolecules, vol. 30, pp. 8000-8009, 1997. 

In real soils where oxides, layer silicates, organic matter and other materials are present in intimate mixtures, with the oxides and organic matter often coating the surfaces of the other materials, the different functional groups interact with... 

Tennakoon DTB, Thomas JM, Tricker MJ, et al. 1974. Smface and intercalate chemistry of layered silicates. Part 1. General introduction and uptake of benzidine and related organic molecrtles by montmorillonite. J Chem Soc Dalton Trans 20 2207-2211. 

On the other hand, Bhattacharya et al. have reported the plasticization effect of organically modified layered silicates on dynamic mechanical properties [13]. In this work, nanocomposites of SBR have been prepared using various nanofillers like modified and unmodified montmorillonite, SP, hectorite etc. It has been observed that the Tg shifts to lower temperature in all the nanocomposites, except for systems from hectorite and NA. This is due to the fact that clay layers form capillaries parallel to each other as they become oriented in a particular direction. Due to wall slippage of the unattached polymer through these capillaries, the Tg is lowered, which could be even more in the absence of organo-modifiers [13]. A similar type of plasticization effect is also noted in the case of the low... 

Keywords Layered double hydroxides Layered silicates Nanocomposites Organic modification Reinforcement Rubber Rubber curatives... 

Fig. 8 Stress-strain plots of layered-silicate-filled NBR cured by sulfur and peroxide (a), sulfur in the presence of different zinc organic salts (b), and peroxide in the presence of different vulcanizing ingredients (c)...

Montmorillonite clays are layered silicates montmorillonite K-10 is a specially manufactured acidic catalyst (Montmorillonite K10, [1318-93-0] A. Comelis, P. Laszlo, M. W. Zettler in eEROS Encyclopedia of Reagents for Organic Synthesis, L. A. Paquette, Ed., John Wiley and Sons, Inc., online reference available at http //www.intersciene.wiley.com)... 

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