Organic Organically modified sodium montmorillonite

The results are reported of an in depth study of the structure, thermal properties, dynamic mechanical properties, flammability and smoke properties of melt blended PVC-sodium montmorillonite nanocomposites. Investigative properties employed included X-ray diffraction, TEM, TGA, DMA and cone calorimetry. The effects of clay loading, DOP concentration, annealing, blending time and molec.wt. on the formation of the composites are discussed and fire properties of PVC-organically modified clay and PVC-sodium clay nanocomposites are presented and discussed. 15 refs. USA... 

Sodium montmorillonite (Na-MMT) was originally modified with pro-tonated amino acids with different numbers of carbon atoms and subsequently swollen with e-caprolactam. Then it underwent polymerization to produce nylon-6 polymer-clay nanocomposite [18]. Later, this technique was also extended to manufacture other thermoplactics. One advantage of this in-situ polymerization technique is the tethering effect, which enables the organic chemical such as 12-aminododecanoic acid (ADA) situated at the surface of the nanoclays to link with nylon-6 polymer chains during polymerization. 

To produce organically-modified montmorillonite, the montmorillonite clay was mixed in water with distearyldimethylammonium chloride. The resulting solid was extracted and washed with sodium chloride solution and ethanol, to remove excess ammonium salt, and freeze dried. To combine with the PCL, the organically-modified montmorillonite was dispersed in chloroform the unmodified montmorillonite would not disperse in this way. Samples with up to 30 wt % clay were produced. 

Three types of binder, bentonite, organic binder and composite binder were used in the experiment. The bentonite was modified sodium bentonite, whose chemical composition is shown in Table 1. The main chemical composition of bentonite was Si02 and AI2O3 and small content of CaO and MgO. The water absorption of bentonite reached 510.3%, the montmorillonite content reached 90.1%, the content of -0.074 mm was 99.9%. The organic binder was synthetic polymer, whose molecule had large number of reactive functional group... 

The effect of mineral and organic soil constituents on the mineralisation of LAS, AE, stearyl trimethylammonium chloride (STAC) and sodium stearate (main soap component) in soils was studied by Knaebel and co-workers [38]. The four 14C-labelled compounds were aseptically adsorbed to montmorillonite, kaolinite, illite, sand and humic acids and subsequently mixed with soil yielding surfactant concentrations of about 50 jig kg-1. The CO2 formation in the serum bottle respirometers was monitored over a period of 2 months indicating that the mineralisation extent was highest for LAS (49-75%). Somewhat lower amounts of produced CO2 were reported for AE and the stearate ranging from 34-58% and 29-47%, respectively. The mineralisation extent of the cationic surfactant did not exceed 21% (kaolinite) and achieved only 7% in the montmorillonite-modified soil. Associating the mineral type with the mineralisation kinetics showed that sand... 

Electrical conductivity measurements have been reported on a wide range of polymers including carbon nanofibre reinforced HOPE [52], carbon black filled LDPE-ethylene methyl acrylate composites [28], carbon black filled HDPE [53], carbon black reinforced PP [27], talc filled PP [54], copper particle modified epoxy resins [55], epoxy and epoxy-haematite nanorod composites [56], polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) blends [57], polyacrylonitrile based carbon fibre/PC composites [58], PC/MnCli composite films [59], titanocene polyester derivatives of terephthalic acid [60], lithium trifluoromethane sulfonamide doped PS-block-polyethylene oxide (PEO) copolymers [61], boron containing PVA derived ceramic organic semiconductors [62], sodium lanthanum tetrafluoride complexed with PEO [63], PC, acrylonitrile butadiene [64], blends of polyethylene dioxythiophene/ polystyrene sulfonate, PVC and PEO [65], EVA copolymer/carbon fibre conductive composites [66], carbon nanofibre modified thermotropic liquid crystalline polymers [67], PPY [68], PPY/PP/montmorillonite composites [69], carbon fibre reinforced PDMS-PPY composites [29], PANI [70], epoxy resin/PANI dodecylbenzene sulfonic acid blends [71], PANI/PA 6,6 composites [72], carbon fibre EVA composites [66], HDPE carbon fibre nanocomposites [52] and PPS [73]. 

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