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Effects of organically modified montmorillonites (OMMTs) with different type and amount of modifiers on flame retardancy of polystyrene (PS) have been studied. The results from morphology analysis, gas chromatography–mass spectrometry and cone calorimeter have showed different mechanisms for the flame retardancy of PS/OMMTs composites, depending on surface property of OMMTs. One is the catalysis of...
The transport properties of select volatile organic compounds were measured in polyurethane/clay nanocomposite barrier membranes as a function of clay content. The nanocomposites were fabricated by two different processing methods involving stirring and sonication of the clay particles. The concentration of Cloisite ® 30B in the nanocomposite was varied from 0 to 50wt%. Characterization of...
This review intends to present different aspects concerning clay/polymer nanocomposites produced by heterophase polymerization in aqueous media. This paper highlights the ability of miniemulsion polymerization to produce clay/polymer nanoparticles with tailored nanostructures. Indeed, this polymerization route enables the synthesis of composite nanoparticles with the clay platelets located either...
This manuscript describes the preparation of polytriazole/clay nanocomposites through in situ polymerization of PTA, using click chemistry, in the presence of a propargyl-modified clay. The clay layers became exfoliated and dispersed well in the PTA matrix, thereby improving the thermal and mechanical properties of the clay. This approach can be extended to combine propargyl-modified clays with other...
This paper aims at elucidating some important parameters affecting the cellular morphology of poly(styrene-co-acrylonitrile) (SAN)/clay nanocomposite foams prepared with the supercritical CO 2 technology. Prior to foaming experiments, the SAN/CO 2 system has first been studied. The effect of nanoclay on CO 2 sorption/desorption rate into/from SAN is assessed with a gravimetric...
Polystyrene-clay nanocomposites were prepared by in situ polymerization to achieve the better dispersion of lamellar silicates i.e. montmorillonite and fluorohectorite and were used to process foams with supercritical CO 2 . Clay–Polymer interactions were modulated by varying the surface treatment of clays: a physical interface was formed with the compatible surfactant showing aromatic groups...
A new type of multifunctional ammonium modifier with carbonyl group and vinyl group was synthesized to prepare multifunctional montmorillonites (F-MMTs), which were used as multifunctional catalyst supports for in situ ethylene polymerization. High loading of metallocene catalyst in the galleries of F-MMT had been achieved due to the presence of carbonyl group in the multifunctional modifier. XRD...
Microgel–clay composite particles were prepared by one-step surfactant–free precipitation polymerization. Laponite nanoparticles present in the reaction mixture become encapsulated during the microgel formation process. Microgel–clay composites based on poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate) containing different amount of incorporated clay nanoparticles were synthesized. The clay...
A novel material comprised of bacterial cellulose (BC) and Laponite clay with different inorganic–organic ratios (m/m) was prepared by the contact of never-dried membranes of BC with a previous dispersion of clay particles in water. Field emission scanning electron microscopy (FE-SEM) data of composite materials revealed an effective adhesion of clay over the surface of BC membrane; inorganic particles...
Though interface has been known for a critical role in determining the properties of conventional composites, its role in polymer nanocomposites is still fragmented and in its infancy. This study synthesized a series of epoxy/clay nanocomposites with different interface strength by using three types of modifiers: ethanolamine (denoted ETH), Jeffamine ® M2070 (M27) and Jeffamine ® XTJ502...
In this article, we report novel epoxy-based hybrids prepared via incorporating 1,2-dimethyl-3-(benzyl-heptaisobutyl-POSS) imidazolium chloride (POSS-IMC) and POSS-IMC-modified clay (POSS-MMT) into the resin based on 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (ECHM) and hexahydrophthalic anhydride (HHPA). We demonstrate that both POSS-IMC and POSS-MMT can reduce the cure temperature...
A low-melting organic-inorganic glass with a high molecular weight soluble in solvents was synthesized by hydrolytic polycondensation of phenyltriethoxysilane followed by a subsequent heat treatment. Softening point and thermostability were strongly increased after heat treatment. The composites of glass/epoxy and glass/clay/epoxy were studied with respect to their thermal properties, fire behavior...
In this study, preparation and electrochemical corrosion protection studies of a series of polyimide–Clay nanocomposite (PCN) materials were first presented. Subsequently, the as-prepared PCN materials were characterized by FTIR, XRD and TEM studies. In-situ monitoring for redox behavior of as-prepared PCN materials was identified by UV–visible and CV studies.It should be noted that PCN coating was...
Second and fourth generations of hydroxylated dendritic polyesters based on 2,2-bis-methylopropionic acid (bis-MPA) with an ethoxylated pentaerytriol (PP50) core were combined with unmodified sodium montmorillonite clay (Na + MMT) in water to generate a broad range of polymer clay nanocomposite films from 0 to 100% wt/wt. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were...
The simultaneous ingress of acetone and water into dried PVOH-clay nanocomposites containing 2.5 wt% or 5 wt% of well dispersed Na-Cloisite, using FTIR-ATR, has been compared with that into pure PVOH films. The rate at which water and acetone moved through the PVOH films is significantly reduced (i) at high acetone concentrations and (ii) when clay is incorporated in the PVOH film. For example, it...
Low flammability, foam-like materials based on bio-based, renewable ammonium alginate and sodium montmorillonite clay were fabricated through a simple, environmentally-friendly freeze-drying process in which water is used as solvent. These materials exhibit mechanical properties similar to those of rigid PU foams or balsa; the compressive modulus (1–97 MPa) and density (0.047–0.174 g/cm 3 ...
Layer multiplying coextrusion was employed to produce films consisting of alternating layers of unfilled and particulate filled polymers, i.e., low density polyethylene (LDPE) and maleic anhydride grafted linear low density polyethylene (LLDPE-g-MA)/organoclay nanocomposites. Layer multiplying coextrusion was employed to produce gas barrier films consisting of alternating layers of unfilled and particulate...
As polymers are rate sensitive to mechanical properties, dynamic tensile tests are carried out on drop mass setup, to obtain medium strain rate stress-strain response which fills the gap between quasi-static strain rate (<10 s−1) and split Hopkinson pressure bar (SHPB) technique (>1000 s−1). The present research work is to study the effect of medium strain rate on tensile behavior of epoxy/clay...
Structural arrest in an aging colloid-polymer mixture of charged colloidal disks and weakly interacting polymers is primarily governed by the spatial arrangement of microstructural domains in the system. Here we present a detailed ultra-small angle x-ray scattering (USAXS) study of the polymer induced microstructural changes occurring in systems containing laponite® and poly(ethylene oxide) (PEO)...
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