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Clay Modification (clay + modification)

Distribution by Scientific Domains

Polymers and Materials Science	100%

Selected Abstracts

Effect of clay modification on the morphological, mechanical, and thermal properties of polyamide 6/polypropylene/montmorillonite nanocomposites

POLYMER COMPOSITES, Issue 7 2010
Kusmono
Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding. The sodium montmorillonite (Na-MMT) was modified using three different types of alkyl ammonium salts, namely dodecylamine, 12-aminolauric acid, and stearylamine. The effect of clay modification on the morphological and mechanical properties of PA6/PP nanocomposites was investigated using x-ray diffraction (XRD), transmission electron microscopy (TEM), tensile, flexural, and impact tests. The thermal properties of PA6/PP nanocomposites were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and heat distortion temperature (HDT). XRD and TEM results indicated the formation of exfoliated structure for the PA6/PP nanocomposites prepared using stearylamine modified montmorillonite. On the other hand, a mixture of intercalated and exfoliated structures was found for the PA6/PP nanocomposites prepared using 12-aminolauric acid and dodecylamine modified montmorillonite. Incorporation of OMMT increased the stiffness but decreased the ductility and toughness of PA6/PP blend. The PA6/PP nanocomposite containing stearylamine modified montmorillonite showed the highest tensile, flexural, and thermal properties among all nanocomposites. This could be attributed to better exfoliated structure in the PA6/PP nanocomposite containing stearylamine modified montmorillonite. The storage modulus and HDT of PA6/PP blend were increased significantly with the incorporation of both Na-MMT and OMMT. The highest value in both storage modulus and HDT was found in the PA6/PP nanocomposite containing stearylamine modified montmorillonite due to its better exfoliated structure. POLYM. COMPOS., 31:1156,1167, 2010. © 2009 Society of Plastics Engineers [source]

Influence of clay modification on the reinforcement of vinyl-terminated polydimethylsiloxane networks

POLYMER INTERNATIONAL, Issue 4 2010
Eung Soo Kim
Abstract A novel method was attempted to reinforce a vinyl-terminated polydimethylsiloxane (PDMS) with two commercially available clays, sodium montmorillonite and Cloisite® 25A. The two clays were functionalized with bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) to prepare Na+MMTS4 and C25AS4, respectively. Incorporation of the tetrasulfide group-containing clays, especially Na+MMTS4, was found to be effective for the enhancement of the interfacial interaction between PDMS and the clays by way of a plausible chemical reaction between the tetrasulfide groups (TSS) and the vinyl-terminated PDMS. Compounding of PDMS with the TESPT-modified clays improved the mechanical properties significantly. In particular, the elongation at break of PDMS/Na+MMTS4 composite was almost twice as high as that of neat PDMS, even if the silicate layers were not fully exfoliated in the PDMS matrix. The tear strength of PDMS was also improved greatly as a result of the incorporation of Na+MMTS4. According to toluene swelling test results, the crosslinking density of the composites was lower than that of neat PDMS, indicating that the improved mechanical properties of the composites arise from enhanced compatibility between the constituents and not from increased crosslinking density. Copyright © 2009 Society of Chemical Industry [source]

Preparation and characteristics of nitrile rubber (NBR) nanocomposites based on organophilic layered clay

POLYMER INTERNATIONAL, Issue 7 2003
Jin-tae Kim
Abstract The effect of clay modification on organo-montmorillonite/NBR nanocomposites has been studied. Organo-montmorillonite/NBR nanocomposites were prepared through a melt intercalation process. NBR nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic mechanical thermal analysis (DMTA) and a universal testing machine (UTM). XRD showed that the basal spacing in the clay increased, which means that the NBR matrix was intercalated in the clay layer galleries. On TEM images, organo-montmorillonite (MMT) particles were clearly observed, having been exfoliated into nanoscale layers of about 10,20 nm thickness from their original 40 µm particle size. These layers were uniformly dispersed in the NBR matrix. The DMTA test showed that for these nanocomposites the plateau modulus and glass transition temperature (Tg) increased with respect to the corresponding values of pure NBR (without clay). UTM test showed that the nanocomposites had superior mechanical properties, ie strength and modulus. These improved properties are due to the nanoscale effects and strong interactions between the NBR matrix and the clay interface. Copyright © 2003 Society of Chemical Industry [source]