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The effects of the dispersion and concentration of single walled carbon nanotube (SWNT) on the flammability of polymer/SWNT nanocomposites were investigated. The polymer matrix was poly (methyl methacrylate) (PMMA) and the SWNT were dispersed using a phase separation (‘coagulation’) method. Dispersion of SWNTs in these nanocomposites was characterized by optical microscopy on a micrometer scale. Flammability...
The measurements of free-volume hole property by positron annihilation lifetime spectroscopy (PALS) have been carried out for polymer–clay nanocomposite materials that consist of styrene–butadiene rubber (SBR) and layered silicate clay of rectorite and conventional composite materials N326 (carbon black) /SBR. The PALS and differential scanning calorimeter (DSC) results show layered rectorite has...
We have prepared polystyrene/clay nanocomposites using an emulsion polymerization technique. The nanocomposites were exfoliated at 3wt% content of pristine clay relative to the amount of polystyrene (PS). We employed two surfactants for the montmorillonite: cetylpyridinium chloride (CPC) and the CPC/α-CD inclusion complex. Prior to polymerization, each surfactant intercalates into the layers of the...
The sodium ions of clays with different cation exchange capacities (CEC) have been exchanged with alkyl ammonium ions, in which 1–4 octadecyl chains are attached to the nitrogen atom. Due to the different cation cross-sectional area to available area per cation ratio, the resulting organo-montmorillonites (OMs) have different organic surface coverage and alkyl chain packing density. Nanocomposites...
A thermoplastic polyolefin (TPO)/organoclay nanocomposite has been successfully prepared by using maleic anhydride modified polypropylene as a compatibilizer. The nanocomposite was characterized by IR spectra, X-ray diffraction and Transmission Electron Microscope. The nanocomposite exhibited remarkable improvement of tensile and storage modulus over its pristine counterpart. Enhancement of storage...
Ethylene terephthalate cyclic oligomers (ETCs) have been successfully polymerized to a high molecular weight poly(ethylene terephthalate) (PET) employing the advantages of the low viscosity of cyclic oligomers and lack of chemical emissions during polymerization. Using ring-opening polymerization of ETCs with organically modified montmorillonite (OMMT), we intend to ascertain the possibility of preparing...
Benzoxazine was synthesized through the Mannich condensation of phenol, formaldehyde, and primary amines through ring-opening polymerization. Polybenzoxazines are phenolic-like materials that possess dimensional and thermal stability, and they release no toxic byproducts during their polymerization. To further improve the thermal stability of polybenzoxazines, a hydrosilane-functionalized polyhedral...
The effects of surfactant structure on the morphology and mechanical properties of melt processed mixtures of poly(styrene-co-acrylonitrile) (SAN) with montmorillonite (MMT) organoclays were examined. The composite which exhibited the greatest change in gallery height, the highest modulus, and greatest aspect ratio (∼50) was produced from an organoclay with the lowest molecular weight surfactant,...
The effect of the organoclay nanoparticles on the rheology and development of the morphology and properties for epoxy/organoclay nanocomposites has been studied. The interlayer spacing increases with the temperature of cure resulting in intercalated morphologies with varying degrees of interlayer expansion, depending on the cure temperature used. Rheological studies of the curing process indicate...
Nanocomposites with both organically modified and unmodified silicate have been prepared by an extrusion process using low and high molecular weight grades of PA6 and a low MW grade of PA66. Mechanical properties have been tested at temperatures ranging from 20 to 120°C. The modulus increase in all nanocomposites with organically modified nanocomposites is similar: at room temperature an increase...
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...
Copolymers consisting of methyl methacrylate (MMA) and methacrylic acid (MAA) and their layered silicate nanocomposites were electrospun to form fibers with diameters in the sub-micron range. The presence of MAA increased the T g and thermal stability of the copolymers through formation of anhydrides upon heating. Fibers of uniform diameters were obtained for the poly(MMA-co-MAA) copolymers...
The diffusion of low molecular weight penetrants through films of a PMDA-ODA polyimide and a corresponding polyimide-silica bicontinuous nanocomposite (organic–inorganic hybrid) was monitored using time-resolved FTIR spectroscopy and gravimetric analysis. A reacting and a non-reacting penetrant, ammonia and water vapour, were used in the study in order to evaluate their relative interactions with...
Poly(ethylene terephthalate-co-ethylene naphthalate) (PETN) nanocomposites containing two different organoclays, Cloisite 20A and 30B, were prepared by melt intercalation using an extruder. The organoclays was treated with epoxy monomer to further improve the polar interactions with PETN matrix. The morphological, thermal-mechanical, mechanical and gas barrier characteristics of the nanocomposites...
A solvent-free reaction of polyethylene-g-maleic anhydride with a tertiary amino alcohol is used to prepare an ammonium carboxylate polyampholyte (PE-g-PA), whose structure is characterized through spectroscopic comparisons to an appropriate model compound. The introduction of ionic functionality results in substantial increases in melt elasticity and viscosity, as well as a demonstrably improved...
The effects of processing history and annealing treatment on the thermal property and polymorphic structure of nylon-6/clay nanocomposites (NCNs) have been investigated. The nanocomposites, including intercalated and exfoliated ones, were prepared by extruding nylon-6 (N6) with sodium montmorillonite (Na-MMT) or organo-montmorillonite (OMMT), respectively. DSC analysis revealed multiple melting endotherms...
Structure and property of a nanocomposite consisting of modified carbon nanofibers (MCNFs), homogenously dispersed in an elastomeric ethylene/propylene (EP) random copolymer (84.3wt% P) matrix, were studied by in situ synchrotron X-ray diffraction during uniaxial deformation. The MCNF acted as a nucleating agent for crystallization of the α-form of isotactic polypropylene (iPP) in the matrix. During...
In this study, poly(ethylene 2,6-naphthalate) (PEN)/layered silicate nanocomposites (PLSNs) were successfully prepared by the intercalation of PEN polymer into organically-modified layered montmorillonite through the melt blending process. Both X-ray diffraction data and transmission electron microscopy images of PEN/layered silicate nanocomposites indicate most of the swellable silicate layers were...
α-Chitin whisker-reinforced poly(vinyl alcohol) (PVA) nanocomposite films were prepared by solution-casting technique. The α-chitin whiskers were prepared by acid hydrolysis of α-chitin from shrimp shells. The as-prepared whiskers exhibited the length in the range of 150–800nm and the width in the range of 5–70nm, with the average length and width being about 417 and 33nm, respectively. Thermal stability...
In this work, we analyze the conductivity data of the nylon 6/FG nanocomposites using the normalized percolation equations and the general effective equation. From the interpretations of the derived results, we demonstrate that the microstructure of the nanocomposites can be readily deduced. Taking several factors into account, it turns out that the tunneling mechanism should be responsible for the...
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