Introduction Of Organoclay Research Articles

Reinforcement of Elastomers Based on Butadiene Rubbers and their Mixtures with Layered Silicates

The rubber compounds based on BR and on mixtures BR with EPDM containing experimental organoclay samples based on bentonites from the “Sarinskoye” deposit (Orenburg Region, Russia), additives to polymers Cloisite® 10A manufactured by Southern Clay Prod. () were compared. The increase of tensile strength at break by introduction of organoclay in rubber compounds based on BR and on mixtures BR with EPDM was determined. The compatibility of rubbers with the introduction of organoclay in the mixture BR with EPDM was improved

Effect of organo-clay on properties and mechanical behavior of Fluorosilicone rubber

High performance Fluorosilicone rubber (FS)/organoclay (OC) nanocomposites have been prepared by a melt compounding process. The results of mechanical investigation revealed that Young’s modulus and hardness of FS rubber are improved with introduction of OCs while an inverse trend was observed for elongation at break and tensile strength. Eight constitutive models, Yeoh, Arruda-Boyce, Mooney-Rivilen, Neo-Hookean, Marlow, polynomial, Van der Waals, and Odgen were studied to investigate the stress-strain behavior of FS/OC nanocomposites. It was concluded that the ability of these models to predict the true behavior of the FS/OC samples directly depends on the amount of OC. Two modified Halpin-Tsai and inverse rule of mixtures theories were applied to evaluate the dependence of Young modulus of nanocomposites on volume fraction of OCs. The experimental data were employed for determining modified models parameters as well as for validating models. It was shown that, OCs can also play a fundamental role in controlling volume shrinkage of FS after cure. FS was proved that still retain its specific properties as well as the fuel and thermal resistance after introduction of OCs. Combination of these results verifies that incorporation of OCs can provide tailored mechanical properties without sacrificing fuel and thermal resistance of FS elastomers.

Synthesis and properties of new clay-reinforced aromatic polyimide/nanocomposite-based 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and 1,3-bis(4-aminophenoxy)propane

AbstractA series of poly(imide-ether)-clay nanocomposite materials-based 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and 1,3-bis(4-aminophenoxy)propane and layered sodium montmorillonite (MMT/Na+) clay were successfully prepared by in situ reaction through thermal imidization up to 200°C. Poly(amic acid) (6) was prepared through the reaction of 1,3-bis(4-aminophenoxy)propane (4) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (5), and then a thermal plan of imidization was used for the synthesis of nanocomposite materials. The resulting nanocomposite films containing 0.5, 1, 3, and 5 wt.% of organoclay were characterized by Fourier transform infrared spectroscopy, wide-angle powder X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis, respectively. The introduction of organoclay in the polymer resulted in improved thermal stability.

Influence of Nanoclay on Morphology, Mechanical Properties and Deformation Mechanism of Polystyrene

Polystyrene/organoclay nanocomposites were prepared by melt intercalation method in this research. Morphology, tensile and impact properties and deformation mechanism of the samples were studied. To study the structure of nanocomposites, X-ray diffraction and transmission electron microscopy techniques are utilized. The deformation mechanisms of different samples were examined via reflected and transmitted optical microscopy. The results reveal that incorporation of organoclay affects structure, mechanical properties and deformation mechanism of nanocomposite. Introduction of organoclay can facilitate initiation and growth of crazing mechanism in polystyrene at both conditions of loadings, i.e., the tensile loading in which crazing occurs in the bulk of the polymer and 3PB testing in which crazing happens at the notch tip of the samples.

Statistical Analysis of Morphology of Low Density Polyethylene/Polyamide 6 Blends with Addition of Organoclay and Maleic Anhydride-Grafted Polystyrene-b-Poly(Ethylene-co-Butene-1)-b-Polystyrene Copolymer As Compatibilizers

Statistical analysis of the size distribution of a polymer minor phase droplets was successfully applied for the characterization of the morphology in a LDPE/PA6 blend (75/25 wt/wt) obtained after mixing with added SEBS-g-MA(S) compatibilizer and/or organoclay 20A. It was shown that the developed approach provided detailed analysis of the morphology development in the polymer blends, including the primary droplets formation of the minor polymer phase and their break-up and coalescence. The introduction of organoclay increased the break-up of primary droplets and completely suppressed their coalescence. The addition of compatibilizer S, in contrast to nanoclay, did not suppress coalescence but the mean size of the primary droplets as well as the droplets formed at coalescence was strongly reduced. The combined addition of compatibilizer S and nanoclay did not change the morphology development of the LDPE/PA6 blend. Both processes of the droplet transformation were accelerated, similar to the system with addition of compatibilizer S only. However, an increase of nanoclay amount disturbed the break-up of the primary droplets, and the mean size of these droplets increases. Thereafter, the mean size of droplets formed at coalescence also increased. The results of statistical analysis of the phase morphology were found to correlate with the mechanical properties of the polymer blends. The fine dispersion of the minor polymer phase improved the stiffness of the polymer blends. For enhanced impact properties, the presence of relatively broad distribution of the minor polymer phase was necessary.

Studies on thermal, mechanical and morphological properties of organoclay filled azomethine modified epoxy nanocomposites

Inter cross-linked networks of organoclay-filled, azomethine-modified epoxy nanocomposites have been developed. Two types of azomethine epoxies (AE1 and AE2) incorporated into diglycidyl ether of bisphenol A (DGEBA) epoxy resin with varying percentages (5, 10 and 15%) were cured with diamine diphenyl methane (DDM). The azomethine epoxies were synthesized and characterized by Fourier transform infrared and 1H-NMR spectroscopy. The incorporation of azomethine epoxies into DGEBA epoxy resin improved both thermal and mechanical properties to an appreciable extent. The introduction of organoclay into DGEBA epoxy resin exhibited almost similar characteristics to that of the azomethine-modified DGEBA epoxy resin. Both azomethine epoxy and organoclay have been incorporated into DGEBA epoxy resin in order to improve the thermal and mechanical properties in comparing other modified epoxies. The glass transition temperature and thermal degradation temperature of azomethine-modified epoxies, organoclay-filled epoxy and organoclay-filled azomethine-modified DGEBA epoxies were determined by using differential scanning calorimeter and thermogravimetric analysis. The mechanical properties, namely the tensile strength, flexural strength and impact strength of the resultant nanocomposites were studied as per ASTM standards. X-ray diffraction studies of the cured nanocomposites indicate that the organophillic montmorillonite clay was exfoliated into the cured product. The homogeneous morphology of azomethine-modified DGEBA epoxy and organoclay-filled azomethine-modified epoxy were ascertained by scanning electron microscopy.

Preparation of thermoplastic elastomer nanocomposites based on polyamide‐6/polyepichlorohydrin‐co‐ethylene oxide

AbstractThis work is aimed at determining the effect of nanoclay and polyepichlorohydrin‐co‐ethylene oxide (ECO) content on the microstructure and mechanical properties of PA6/ECO thermoplastic elastomers (TPEs). TPE nanocomposites were prepared in a laboratory mixer using polyamide 6 (PA6), ECO, and an organoclay by a two‐step melt mixing process. First, the PA6 was melt blended with Cloisite 30B and then mixed by ECO rubber. X‐ray diffraction results and transmission electron microscopy image showed that the nanoclay platelets were nearly exfoliated in both the phases. The SEM photomicrograph of PA6 with ECO showed that the elastomer particles are dispersed throughout the polyamide matrix and the size of rubber particles is less than 3 μm. Introduction of organoclay in the PA6 matrix increased the size of dispersed rubber particles in comparison with the unfilled but otherwise similar blends. The nanoscale dimension of the dispersed clay results in an improvement of the tensile modulus of the nanocomposites. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

The Impact of Organoclay on the Physical and Mechanical Properties of Epoxy-Clay Nanocomposite Coatings

Nanocomposite coatings have recently been of interest because of their superior technical, environmental and economical advantages. Some new solvent free nanocomposite coatings were formulated using epoxy resin and montmorillonie (MMt) nanoclay. The organomodified MMt was well dispersed and partially exfoliated in the epoxy resin. The dispersion process comprised high-shear mixing and ultrasonication. The structure of the resultant coatings was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses. The effect of the clay content on the physical and mechanical properties of the resultant coatings, such as abrasion and impact resistance, hardness, and flexibility were measured and compared with unmodified coatings. The introduction of organoclay up to 4 wt% in coating systems resulted in improvement in the physical and mechanical properties such as hardness (micro and König) and abrasion resistance. Also an increment of up to 3 wt% of organoclay leads to an increase in the impact resistance and flexibility of resultant coating films. On the other hand, flexibility and impact resistance of the coatings containing more than 3 wt% of clay was decreased. The main reason for these observations was agglomeration of the clay particles for high clay-loading compositions.

Influence of PP‐g‐MA on morphology, mechanical properties and deformation mechanism of copolypropylene/clay nanocomposite

AbstractCopolypropylene/organoclay nanocomposites are prepared by melt intercalation method in this research. Two different routes for addition of compatibilizer are examined, i.e. addition in the twin‐screw extruder along with the polymer and the clay powder simultaneously and premixing the compatibilizer with the reinforcement in a batch mixer before addition to the polypropylene (PP) matrix. Morphology, tensile and impact properties and deformation mechanisms of the samples made via two procedures are studied and compared with those of the noncompatibilized system. To study the structure of nanocomposites, x‐ray diffraction and transmission electron microscopy techniques are utilized. The deformation mechanisms of different samples are examined via reflected and transmitted optical microscopy. The results reveal that introduction of compatibilizer and also the procedure in which the compatibilizer is added to the compound, affect structure and mechanical properties of nanocomposite. The elastic modulus of PP‐clay nanocomposite has increased 11.5% with incorporation of compatibilizer. Also, introduction of organoclay without compatibilizer facilitates crazing at the notch tip of PP in 3PB testing. Incorporation of compatibilizer, however, makes difficulties in initiation and growth of crazes at the notch tip. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Influence of Organoclay on the Physical Properties of Polyethylene Nanocomposites

In this work, polyethylene/montmorillonite clay nanocomposites were produced by melt intercalation. The clays were treated with quaternary ammonium salts and then treated and untreated clays were introduced in polyethylene. The clays were characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The nanocomposites were characterized by mechanical and flammability properties. The results showed that the mechanical properties were improved by introduction of organoclay in polyethylene matrix. By adding only 3wt% montmorillonite, the burning rate of the nanocomposites was reduced by 17% in relation to PE matrix.

A study on phase morphology and surface properties of polyurethane/organoclay nanocomposite

In this study, polyurethane/organically modified layered silicate (organoclay) nanocomposites were prepared through in situ polymerization in the presence of organoclay. Phase morphology of the polyurethane/organoclay nanocomposite was investigated by small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM). The results suggest that the inter-domain repeat distance decreased with the introduction of organoclay. The organoclay has a more significant effect on the inter-domain repeat distance at a low hard segment content. Also with the increase of the hard segment, the inter-domain repeat distance and domain size increased markedly. The size of hard domain of the polyurethane was found to be in the range of 12–32 nm in this case, and it keeps nearly unchanged with the clay content. It is suggested by AFM phase imaging technique that the hard domain can self-organize further to form spherical aggregates. The introduction of clay into the polyurethane matrix resulted in the decrease in the size of the spherical aggregates from ∼800 nm to ∼500 nm, indicating clay has an important effect on the aggregation behavior of hard domains. The effect of clay on the surface energy was examined by means of AFM and goniometry techniques. The results obtained by two methods are consistent, i.e., with the increase of clay content, the surface energy decreased due to the effect of organic modifier.