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Via in situ intercalative free-radical polymerization, we prepared clay/poly(methyl methacrylate) (PMMA) and clay/polystyrene (PS) nanocomposites from lipophilized smectic clays. The intercalation spacing in the nanocomposites and the degree of dispersion of these composites were investigated with X-ray diffraction and transmission electron microscopy, respectively. Under some conditions, the intercalative...
The effect of polar comonomers introduced into polystyrene (PS) chains on the melt intercalation into organosilicate is investigated in terms of shear and annealing time. In the case, where the interaction between polymers and silicate layers is relatively weak, e.g. PS/organosilicate hybrids, it is difficult for the polymer chains to diffuse into interlayers of organosilicate and the hybrids are...
The fabrication of nanocomposite of syndiotactic polystyrene (sPS)/organophilic clay was conducted by melt intercalation. To avoid the decrease of interlayer spacing due to desorption of organic materials at high temperature, various amorphous styrenic polymers were introduced during the melt mixing process. The nanocomposites were fabricated via two different methods, one is the stepwise mixing method,...
Simple shear of end-tethered Nylon 6–clay nanocomposites and the preservation of these effects into the crystalline state is reported. Typical conditions leading to mesoscopic (clays) and molecular (polymer chains) orientation of these systems at relatively low shear rates and at temperatures immediately above the nominal melting point showed a morphological change proportional to the shear time in...
This work has demonstrated that the addition of optimum content of D-2000 modified montmorillonite enhances the ionic conductivity of the poly(ethyl oxide) (PEO) based electrolyte by nearly sixteen times more than the plain system. Specific interactions among silicate layer, ethyl oxide and lithium cation have been investigated using alternating current impedance (A.C. impedance), differential scanning...
Syndiotactic polystyrene/modified-clay nanocomposites have been prepared by solution blending by mixing pure s-PS and organophilic clay with adsorbed cetyl pyridium chloride (CPC) in dichlorobenzene. The dispersability of the clay in syndiotactic polystyrene/modified-clay nanocomposites was studied using X-ray and transmission electron microscopy. The clay is well dispersed into the s-PS matrix using...
A kind of novel polyurethane/Na + -montmorillonite nanocomposites has been synthesised using modified 4,4'-di-phenymethylate diisocyanate (M-MDI), modified polyether polyol (MPP) and Na + -montmorillonite (layered clay). Here, MPP was used as a swelling agent to treat the layered clay. Experimental results indicated that with increasing the amount of layered clay, the strength and...
Melt compounding was used to prepare conventional composites of montmorillonite clay and polyethylene (PE) as well as nanocomposites of exfoliated montmorillonite platelets dispersed in a maleated polyethylene (PE-g-MAn) matrix. The extent of clay platelet exfoliation in the PE-g-MAn nanocomposites was confirmed by X-ray diffraction and resulted in a significant reduction of the degree of crystallinity...
We report a novel compounding process using Na–montmorillonite water slurry for preparing novel nylon 6/Na–montmorillonite nanocomposites. In this compounding process, the Na–montmorillonite slurry was blended with melting nylon 6 using an extruder, followed by removing the water. The Na–montmorillonite silicate layers were found to be exfoliated and dispersed homogeneously at nanometer level in the...
Nylon 11/organoclay nanocomposites have been successfully prepared by melt-compounding. X-ray diffraction and transmission electron microscopy indicate the formation of the exfoliated nanocomposites at low clay concentrations (less than 4wt%) and a mixture of exfoliated and intercalated nanocomposites at higher clay contents. Thermogravimetric and dynamic mechanical analyses as well as tensile tests...
The polymerization of N-vinyl-2-pyrrolidone catalyzed by the Maghnite-H + (Mag-H) was investigated. Mag-H is a montmorillonite sheet silicate clay, exchanged with protons. It was found that the cationic polymerization of N-vinyl-2-pyrrolidone (NVP) is initiated by Mag-H at 30 °C in bulk and in solution. The effect of the amount of Mag-H, the temperature and the solvent was studied. The polymerization...
A hybrid polyethylene-clay nanocomposite was prepared using in situ polymerization with bifunctional organic modifiers. Morphological characterization of the product shows that a fraction of the polyethylene chains is chemically linked to the silicate surface. The chemical modification and intercalation of montmorillonite was carried out with alkylaluminum and vinylalcohol. The vinyl groups chemically...
A method was described for synthesis of exfoliated poly(styrene-co-methyl methacrylate)/clay nanocomposites through an emulsion polymerization with reactive surfactant, 2-acrylamido-2-methyl-1-propane sulfonic (AMPS) which made the polymer end-tethered on pristine Na-MMT. AMPS widened the gap between clay layers and facilitates comonomers penetrate into clay. Silicate layers affect the composition...
In this paper, we report the preparation of in situ blends of metallocence polyethylene (mPE) with montmorillonite (clay). The polymerization activity of polyethylene decreases upon increasing the amount of the clay feed. The mPE nanocomposites still possess their original melting and crystallization temperatures, but the melting and crystallization enthalpies decrease upon increasing the clay content...
A series of EVA/clay nanocomposites and microcomposites have been prepared via melt-blending. Using four kinds of EVA with different vinyl acetate (VA) contents: 28, 40, 50 and 80wt%, and four kinds of clay: three are organophilic clay (OMMT) and one unfunctionalized clay (Na-MMT), the effects of different VA content of EVA and the kinds of the clay on the morphology and properties of EVA/clay nanocomposites...
The fabrication of a syndiotactic polystyrene (sPS)/organoclay nanocomposite was conducted via a stepwise mixing process using poly(styrene-co-vinyloxazolin) (OPS), i.e. melt intercalation of OPS into organoclay followed by blending with sPS. The effects of several parameters, including type of organoclay and mixing temperature on the microstructure of the nanocomposite were investigated through X-ray...
Poly(methyl methacrylate) (PMMA)-clay nanocomposites were prepared by a heterocoagulation method. A cationic PMMA emulsion was prepared by emulsion polymerization using a cationic initiator in the presence of free surfactant, cetyl trimethylammonium bromide (CTABr), followed by mixing with an aqueous clay slurry. Clays used in present research included montmorillonite (MMT), synthetic hectorites and...
Propropylene (PP) and polyamide-6 (PA6) alloys nanocomposites were prepared using melt intercalation technique by blending PP and PA6 while used organophilic montmorillonite (OMT). The melt intercalation of PP and PA6 alloys was carried out in the presence of a compatibilizer such as maleic anhydride-g-polypropylene (MAPP). Their structures were characterized by scanning electron microscope (SEM),...
Polystyrene clay nanocomposites can be prepared via several different methods, including in situ polymerization, melt compounding, or solvent blending. In this paper, we investigate solvent blending which is facilitated by high power sonication to prepare an exfoliated polystyrene-clay nanocomposite. The effects of clay type as well as sonication during solvent blending in regards to degree of clay...
The degradation pathway of polyamide 6/clay nanocomposites was studied as a function of clay content. Well-dispersed polymer–clay nanocomposites can be easily obtained by simple melt blending between organically-modified clays and polyamide 6. Polyamide 6–clay nanocomposites exhibit a large reduction in the peak heat release rate, 60%, measured by cone calorimetry. There are no significant differences...
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