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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...
The catalyst system consisting of Y(CF 3 CO 2 ) 3 , Zn(Et) 2 , and pyrogallol in the solvent of 1,3-dioxolane was found to be effective for the copolymerization of allyl glycidyl ether with carbon dioxide at 60 o C and 400psi. The IR, 1 H-NMR, and 13 C-NMR spectra as well as the element analysis indicated that the resulting copolymer was...
The vulcanization kinetics of gum and montmorillonite (Na-MMT) clay filled fluoroelatomer (FKM) nanocomposite was studied using both oscillating disc rheometer and differential scanning calorimetry under isothermal and dynamic conditions. The X-ray diffraction pattern of clay filled FKM showed a shift in d-spacing toward higher values indicating the formation of intercalated silicate layer. The cure...
Sodium montmorillonite (Na-MMT) absorbed a radical initiator, potassium persulfate (KPS), by way of hydrogen bonding between hydroxyl groups in the Na-MMT lattice and the sulfonic anions of KPS. FT-IR absorbance bands of hydroxyl groups in the Na-MMT lattice and the sulfonic anions of KPS shifted to lower wavenumber regions, compared with the free silicate and the initiator. The amounts of initiator...
Nanocomposite materials were prepared from poly(oxyethylene) (POE) as the matrix and a stable aqueous suspension of cellulose nanocrystals extracted from tunicate as the reinforcing phase. After dissolving POE in water and mixing with the cellulose nanocrystals suspension, solid films were obtained by casting and evaporating the preparations. Resulting films were characterized using scanning electron...
The thermal and flammability properties of polypropylene/multi-walled carbon nanotube, (PP/MWNT) nanocomposites were measured with the MWNT content varied from 0.5 to 4% by mass. Dispersion of MWNTs in these nanocomposites was characterized by SEM and optical microscopy. Flammability properties were measured with a cone calorimeter in air and a gasification device in a nitrogen atmosphere. A significant...
Colloidal boehmite particles have been included into a polyamide-6 matrix by in situ polymerization. The particles have been used without any surface modification. Characterization of the nanocomposites has been carried out using transmission electron microscopy (TEM), dynamical mechanical analysis (DMA) and differential scanning calorimetry (DSC). TEM images indicate that the particles have been...
A high-density polyethylene (HDPE)/isotactic polypropylene (PP) (75/25) blend containing 25wt% of PP was fibrillated by roller drawing at 138 o C. The fibrillated blend was processed again at temperatures ranging from 155 to 200 o C by compression molding or extrusion. The effects of molding temperature on the morphology and mechanical properties of the blend were investigated. Wide...
Linear polyethers possess unusually high CO 2 solubility and, hence, selectivity due to the presence of accessible ether linkages that can interact with the quadrupolar moment of CO 2 molecules. In this work, membranes derived from crosslinked poly(propylene glycol) diacrylate (PPGda) oligomers differing in molecular weight (M), as well as PPGda nanocomposites containing either an...
A method to determine the orientation distribution function of montmorillonite clay in nylon 6 nanocomposite films by a combination of infrared (FTIR) trichroic analysis and transmission electron microscopy (TEM) image analysis is described. The structural absorbance of the nanoclay Si-O vibrations was obtained by the sample tilting method described by Schmidt [Schmidt PG. J Polym Sci: Part A 1963;1:1271-1292]...
Dielectric spectroscopy was conducted during extrusion processing of polyamide-6 (PA6) and layered silicate/polyamide-6 nanocomposites. Dielectric dispersion parameters were identified that appear sensitive to layered silicate concentration and degree of exfoliation. Specific to measuring layered silicate concentration is that the Maxwell–Wagner strength of dispersion, Δε mw , increases linearly...
The purpose of this study is to develop novel poly(vinyl alcohol) (PVA)/poly(ethylene glycol) (PEG) hydrogel blends and PVA-derived organic–inorganic hybrid materials and perform nanostructural characterizations. PVA and PEG hydrogels were prepared by dissolving the polymer in aqueous solution, followed by addition of glutaraldehyde (GA) chemical crosslinker. Hybrids were synthesized by reacting PVA...
This work investigates the melt-processing of styrene–acrylonitrile copolymer (SAN) with organo-modified montmorillonite (MMT) clays and the influence of the clay on mechanical properties and on fire performance of SAN. The nanodispersion of MMT is evaluated qualitatively by X-ray diffraction (XRD) and transmission electronic microscopy (TEM), and quantitatively by solid state nuclear magnetic resonance...
Poly(phenylene oxide) (PPO)/polyamide 6 (PA6) (50/50 w/w) blend nanocomposites were prepared by melt mixing of PPO, PA6, and organically modified clay. The morphology of PPO/PA6 nanocomposite with various amounts of clay has been investigated using scanning electron microscope (SEM), transmission electron microscope (TEM), and wide-angle X-ray diffraction (WAXD). For the PPO/PA6 blend without clay,...
Most of work on polymer/layered silicate nanocomposites (PLSN) focused on the importance of the chemistry used to modify the surface of the clay, usually montmorillonite (MMT) and characterization of the nano-scale structure obtained in the last decade. The role and importance of processing has been paid attention only recently. Our purpose of this study is to determine the effect of the chemistry...
The morphology, mechanical, and barrier properties of composites derived from phosphonium bromide ionomer derivatives of an isobutylene-based elastomer (IIR-PPh 3 Br) are compared with analogous non-ionic composites. Improved adhesion between the ionomer and onium ion-exchanged montmorillonite clay (NR4+-MM) allowed standard polymer compounding techniques to yield highly reinforced elastomer...
Detection and monitoring of hazardous species like HCl, by fast, simple, cost effective, highly specific and selective devices is the main issue for environmental scientists. The currently available detection methods are either indirect or time consuming and expensive. These sensors are operated at high temperatures and response time is very slow. The nanocomposite polymeric combinations have come...
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...
A study of the changes in crystal perfection of polyamide 66 (PA66) and polyamide 66/clay nanocomposites (PA66CN) due to different thermal processing was carried out. We designed three series of thermal processing including melt-quench (MQ), post-annealing MQ sample (MQA), and melt–slow cooling–annealing (MSA). The annealing temperature was set as 180 or 210°C, which is within Brill temperature range...
A series of composites of polycarbonate (PC) with 23 different contents of multiwalled carbon nanotubes (MWNT) was produced by melt mixing using the masterbatch dilution method. In dielectric measurements, AC conductivity and complex permittivity data obtained in the frequency range between 10 −3 and 10 7 Hz at room temperature indicated the electrical percolation threshold at about...
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