Effect Of Nanoclay Research Articles

Morphology and Properties of Poly(Lactic Acid) and Ethylene-Methyl Acrylate Copolymer Blends with Organoclay

The effects of nanoclay with surface modified by 25-30 wt% of octadecylamine (Clay-ODA) on mechanical, thermal and morphological properties of poly(lactic acid) (PLA)/ethylene-methyl acrylate copolymer (EMAC) blends with various Clay-ODA contents were investigated. The EMAC with 19.60 wt% of methyl acrylate (or EMAC1820) was used, and the ratio of PLA and EMAC1820 was 80/20 by weight, and the Clay-ODA contents were 1, 3, 5 and 7 phr. The morphology analysis showed that the addition of Clay-ODA could improve the miscibility of PLA/EMAC1820 blends due to the decrease the domain sizes of dispersed EMAC1820 phase in the PLA matrix. The mechanical properties showed Young’s modulus, stress at break and storage modulus of PLA/EMAC1820 blends was improved after adding Clay-ODA. The addition of Clay-ODA did not effect on the melting temperature and glass transition temperature of PLA and PLA blends. The thermal stability of PLA could improve by adding EMAC1820 and Clay-ODA.

Effect of nanoclay on carbon black reinforced blend of amorphous–semicrystalline polymers

In this work, the effect of nanoclay in carbon black reinforced PC-PBT has been investigated on the basis of changes in their mechanical and thermal properties. It has been believed on the basis of FESEM images that CB supports for the expansion of PBT rods and PC wraps around these expanded rods. However, the effect of reinforcing filler for improvement in mechanical properties has been found insignificant which may be due to the agglomeration of reinforcing particles. Addition of nanoclay in carbon black reinforced PC-PBT composite blend shown considerable improvement in its tensile strength (113%). This should be due to the improved dispersion of CB in polymer matrix and better linked-up structure of PBT rods after addition of NC. In addition, this combination has shown simultaneous improvement in tensile strength and ductility which is unusual and may be desirable in many structural applications.

Effect of organically modified montmorillonite clay on the properties of hydroxyl terminated polydimethyl siloxane

Hydroxyl-terminated poly(dimethylsiloxane) cured by a mixture of methyl tris (methyl ethyl ketoxime) silane and 3-aminopropyl triethoxy silane system is known for satisfactory mechanical properties and chemical resistance. The effect of nanoclay on this poly(dimethyl siloxane) (PDMS) system is explored in this study. Organically modified clay (montmorillonite) nanocomposites of PDMS were processed by solution blending followed by cross linking. The effect of nanoclay content on the mechanical, barrier, thermal and dynamic mechanical properties of the nanocomposites were investigated in detail. X-ray diffraction studies reveal exfoliated nature of the nanoclay layers in the composites. The mechanical properties, such as tensile strength and elongation at break of PDMS, improved substantially on reinforcement with nanoclay. The maximum enhancement in properties occurred at a nanoclay content of 2-3%. Cross-link density increased with increase in nanoclay concentration up to 3% and decreased with further addition. The barrier properties were not significantly altered by the incorporation of nanoclay. Initial decomposition temperatures marginally increased at lower loading levels of nanoclay, whereas a reverse trend is observed at higher loadings. The glass transition temperature remains practically the same for all the compositions. The study demonstrates that nanoclay addition is an effective method for improving the properties of PDMS.

Investigating the Effects of Nanoclay and Nylon Fibers on the Mechanical Properties of Asphalt Concrete

This paper describes the effects of reinforcement by randomly distributed nylon fibers and addition of nanoclay on some engineering properties of a typical asphalt concrete. The properties of asphalt concrete reinforced by different percentages of 25 mm nylon fibers have been compared with those of the mixtures containing different percentages of nanoclay and those in which both the fibers and nanoclay have been included. Engineering properties, including Marshall stability, resilient modulus, dynamic creep and fatigue life have been studied. Nylon fibers have been used in different percentages of 0.1, 0.2, 0.3 and 0.4% (by the weight of total mixture), and nanoclay has been used in 2, 4 and 7% (by the weight of bitumen). It is found that the addition of fibers is more effective than the nanoclay for increasing the resistance against fatigue cracking. However, nanoclay improves the resistance of the mixture against permanent deformation better than the nylon fibers. The results also show that the mixture reinforced by 0.4% of nylon fibers and containing 7% of nanoclay has the highest resilient modulus, Marshall stability and fatigue life. However, the mixture containing only 7% of nanoclay has the highest resistance against permanent deformation.

Effect of nanoclay on the mechanical behavior of epoxy composites

Abstract The present study investigated the mechanical characteristics of epoxy strips reinforced with Cloisite 30B nanoclay. Epoxy materials were reinforced with different particulate fractions of chosen nanoclay and the specimens were investigated regarding mechanical properties such as tensile, impact and flexural strengths. The nanoclay content was varied from 2 to10 wt.-% of the total matrix in the matrices. The results showed that the mechanical properties of the composites mainly depended on the dispersion condition of the filler particles, particle size and aggregate structure. Improved tensile modulus, flexural modulus and impact strength in bending properties with less nanoclay content were observed and were found to decrease with increased filler content.

Investigation of polyethylene‐grafted‐maleic anhydride presence as a compatibilizer on various properties of nanocomposite films based on polyethylene/ethylene vinyl alcohol/ nanoclay

High oxygen barrier films were prepared based on low‐density polyethylene (LDPE)/ethylene vinyl alcohol (EVOH)/ nanoclay and polyethylene‐grafted‐maleic anhydride (LDPE‐g‐MA) as a compatibilizer. Box–Behnken statistical experiment design methodology was employed to study the effects of nanoclay, LDPE‐g‐MA, and EVOH presence and their contents on various properties of the final films. The R2 parameter varied between 0.89 and 0.99 for all the obtained responses. The morphology of the samples was evaluated. Results of oxygen transfer rate (OTR) test indicated that the addition of EVOH up to 30 wt% to neat LDPE can decrease oxygen permeability significantly. The addition of nanoclay also decreased the permeability of resulting films but, LDPE‐g‐MA reduced the permeability of the films only at an optimal content. Elastic modulus was increased with the addition of nanoclay, EVOH, and LDPE‐g‐MA to the matrix. An increase in EVOH content in the samples improved the tensile strength. Effect of nanoclay on tensile strength was highly dependent on the presence of a compatibilizer. The addition of compatibilizer to the samples and increasing its content enhanced the tensile strength of the specimens. Incorporation of nanoclay, EVOH, and LDPE‐g‐MA to the LDPE matrix and increasing the amount of these components in the samples led to higher storage modulus, zero shear rate viscosity, and shear thinning exponent, but, lowered the terminal slope and the frequency of intersection point of storage modulus (G′) and loss modulus (G″). The only exception was that EVOH increment resulted in a lower shear thinning exponent. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of Nano Clay on Corrosion Protection of Zinc-rich Epoxy Coatings on Steel 37

Epoxy zinc rich coatings containing clay nanoparticles were prepared and the effect of clay content on the cathodic protection performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and immersion test. Open circuit potential (OCP) measurements and immersion tests were also carried out to better understand the behavior of zinc rich coating. EIS and OCP measurements showed that addition of 1 wt% clay improved the cathodic protection duration and sacrificial properties of the epoxy zinc rich coating. Transmission electron microscopy (TEM) photographs confirmed that clay nanoparticles were successfully dispersed in the coating matrix loaded with 1 wt% clay. Immersion test results indicated that addition of 1 wt% clay nanoparticles in zinc rich epoxy coatings increased the cathodic protection ability of coatings.

Effect of nanoclay on the nucleation, crystallization and melting behaviour of polypropylene

Non-isothermal crystallization kinetics of virgin polypropylene (PP) and its nanocomposites have been evaluated using differential scanning calorimetric technique. The nanocomposites were prepared using melt intercalation method. It is observed that the crystallization peak temperature of nanocomposite is marginally higher than virgin PP at various cooling rates. The non-isothermal crystallization melt data were analysed using Avrami, Ozawa and Mos models. The half-time for crystallization decreased with incorporation of clay nanoparticles. The values of crystallization rate constant and cooling rate at unit crystallization time showed that the crystallization rate increased with the increasing of cooling rates for virgin PP and nanocomposite, but the crystallization rate of nanocomposite was faster than that of PP at a given cooling rate. The activation energy for non-isothermal crystallization of virgin polymer and nanocomposites based on Kissinger method has been determined to be 186 and 196 kJ mol−1, respectively. The polarized micrographs showed that the number of effective nuclei increased in the PP-clay nanocomposite, where the clay acts as a heterogeneous nucleating agent during the crystallization of the nanocomposite.

Investigation of mechanical, thermal and surface properties of nanoclay/HDPE nanocomposites produced industrially by melt mixing approach

The main aim of this paper is to introduce mechanical, thermal and surface properties of produced industrially HDPE-based nanocomposites. For this purpose, 1.0, 2.0, 3.0, 4.0 and 5.0 wt.% loading of nanoclay-reinforced HDPE nanocomposites made from the HDPE matrix were prepared by the melt mixing method using a compounder system, which consist of industrial banbury mixer, single screw extruder and granule cutting. The effect of nanoclay on mechanical, thermal and surface properties of nanoclay/HDPE nanocomposites was investigated. The tensile and flexural strength of nanoclay/HDPE nanocomposite increased by about 5% and 7%, respectively, with addition of 1.0 wt.% nanoclay. But then it decreased slightly as the nanoclay content increased to 5.0 wt.%. The tensile modulus and tensile elongation were decreased with the addition of 1.0 wt.% nanoclay, but did not increase further as more nanoclay was added. The flexural modulus of HDPE was significantly improved after (from 1.0 wt.% up to 5.0 wt.%) addition of nanoclay. It was found that the scratch resistance of nanoclay/HDPE nanocomposite improved with addition of the nanoclay by SEM examination. Density, melting flow index (MFI), differential scanning colorimetry (DSC), and vicat softening temperature (VICAT) were used to characterize the physical and thermal properties of the nanocomposites. The X-ray diffraction (XRD), the Fourier transform infrared spectrophotometry (FTIR), and the scanning electron microscopy (SEM) were used to analyze the structural characteristics of the nanocomposites. It is concluded that the addition of the nanoclay in HDPE has significantly influenced the mechanical, thermal, and surface properties of the nanocomposites.

An experimental study on low-velocity impact response of nanocomposite beams reinforced with nanoclay

The low-velocity impact (LVI) response of the unidirectional glass/epoxy laminated composites, which were reinforced with various contents of nanoclay (i.e., 0, 3, 5 and 7 wt %) was performed using a drop-weight impact machine. The nanocomposite beams were fabricated using two different methods, including hand lay-up (HLU) and vacuum assisted resin transfer molding (VARTM) methods, to evaluate the effect of the manufacturing method on the impact response. In addition, the influence of the nanoclay type on the impact response was assessed by using Cloisite 30B and Cloisite 15A. The quasi-static and LVI responses of the nanocomposite beams were compared, and the effect of nanoclay on the delaminated area after impact was also discussed. The comparative results of the experiments indicate that the samples fabricated via VARTM method, have a smaller damage area and more energy absorption than the HLU types. However, the beams with 5 wt % nanoclay have the highest energy absorption in both manufacturing methods. Moreover, the mechanism of smaller delaminated area with increasing nanoclay contents is explained according to the impermeable nature of nanoclays.

Effect of nanoclay on the transfer properties of immanent additives in food packages

Polymer nanocomposites and specifically clay-based nanocomposites are emerging in the food packaging area and are promised to have a growing market. While the advantages of the nanoparticles on the gas barrier properties of the nanocomposites are already well-investigated and confirmed, the effect of these nanoparticles on the migration of other non-nano and potentially toxic components of the polymer packaging has still remained unclear. The present study addressed the effect of nanoclay on the migration of various additives from nanoclay/LLDPE nanocomposite packaging by determining the apparent diffusivity of these additives from the samples in contact with four different types of food simulants that distinctively exhibit hydrophilic and lipophilic characters. The results indicated that apart from the tortuosity effect that influence in a low extent the diffusivity of model migrants, the presence of nanoclays modifies the transport properties of materials as a result of their impact on other factors such as crystallinity and swelling capacity. PLS analysis on the influential geometrical and physical properties additionally revealed that the affinity between the food simulant and the polymer has the dominant effect on determining the order of apparent diffusivity as well as the effectiveness of barrier properties of nanoclays to reduce the diffusivity of additives through food packaging. Such statements suggest a benefit provided by nanoparticles incorporation in terms of the human exposure to plastic additives.

Influence of nanoclay on mechanical and thermal properties of glass fiber reinforced polymer nanocomposites

A novel approach was carried out to evaluate the effects of nanoclay in nanocomposite laminates based on mechanical properties, thermal analysis, and surface structure analysis. The composite panel was fabricated by reinforcing glass fiber with epoxy resin. Likewise, nanocomposite panels were fabricated by reinforcing glass fiber with nanoclay loaded epoxy. The loading of Cloisite 25A nanoclay in epoxy resin is varied as 2%, 4%, 6%, 8%, and 10% on weight basis. Upon completion of curing, the composite panel and nanocomposite panels were fabricated by using compression molding. The tensile test exhibited that the addition of nanoclay in epoxy resin has improved the tensile strength and Young's modulus by 33.39% and 15.88%, respectively for 2 wt% clay loading laminates than unfilled laminate. Likewise, the greater flexural strength of 438.04 MPa and flexural modulus of 22.12 GPa were attained for 2 wt% nanoclay/epoxy nanocomposite. The thermal results disclosed that greater thermal stability was attained between temperatures ranges from 0°C to 180°C for low clay content. The surface morphology too proved that the prepared laminates of 2 wt% loading exhibited appreciable surface property. POLYM. COMPOS., 39:1861–1868, 2018. © 2016 Society of Plastics Engineers

Melt rheological behavior of PMMA nanocomposites reinforced with modified nanoclay

Poly(methyl methacrylate) (PMMA) nanocomposites containing nanoclay with and without compatibilizer (PMMA-g-MA) were prepared by melt blending followed by compression molding in order to investigate the rheological and flammability properties of developed nanocomposites. The rheological measurements at various temperatures and frequencies were performed using rheometer with parallel-plate geometry. The frequency sweep result revealed that storage modulus improved with the addition of nanoclay at lower frequency and gradually changed from liquid-like behavior to solid-like behavior due to the formation of percolating network structure. For all the samples, complex viscosity decreased as the temperature increased. Similarly, dynamic mechanical investigations exhibited a significant enhancement in storage modulus at lower temperature due to reinforcing effect of nanoclay. The flammability test also demonstrated that rate of burning was reduced by 37% with the addition of nanoclay.

Investigation of Stabilised Batu Pahat Soft Soil Pertaining on its CBR and Permeability Properties for Road Construction

Soil stabilization by adding materials such as cement, lime and bitumen is one of the effective methods for improving the geotechnical properties of soils [11] Nano-particle is one of the newest additives and many studies about using nano-particle in soil improvement has been done but it was given less attention when soft clay soils stabilization is concerned. To evaluate the strength characteristics of stabilized Batu Pahat soft clay, laboratory investigation on early strength gained by the stabilized soil must be conducted to formulate a suitable and economical mix design [10]. To achieve such purpose, the study examined the effect of NanoClay on the California Bearing Ratio and the Permeability of soft clay. The results gained shows that the Nano-Clay is able to increase the strength of the soft clay [9]. The California Bearing Ratio of the soil is increase significantly where the results for the highest percentage of admixture is 14.4% while the permeability of the soil decreases significantly with increasing Nano-Clay whereby the results of the highest percentage of admixture is 2.0187x10-11 m/s. After doing this research, it is proven that Nano-clay can contribute towards better soil stabilization and enhance the quality of soil as subgrade and foundation at large.

Characterization of styrene- co -butyl acrylate/Cloisite Na + nanocomposite film synthesized via soap free emulsion polymerization

Abstract The formation of stable armored styrene- co -butyl acrylate/Cloisite Na + latex particles up to 250 nm which was synthesized by soap free emulsion polymerization method and thereafter, characterization of derived nanocomposite films was studied by many analysis such as transmission electron microscopy, low angle X-ray diffraction, Oxygen Transmission Rate (OTR), water vapor transmission rate (WVTR), water uptake and contact angle. The results of this research work revealed exfoliated nanoclay structure for the samples containing 6 and 8 wt% Cloisite Na + and intercalated nanoclay structure for sample containing 10 wt% Cloisite Na + . The barrier properties of these clear films processed from aforementioned latexes was according to the well dispersion of clay layers within the nanocomposite matrix. Drastic reduction of OTR and WVTR were observed by increasing the clay loading up to 10 wt%. The increase in tensile strength and Young’s modulus of nanocomposite films showed high effects of nanoclay on the film mechanical properties, mainly due to the presence of the delaminated clay layers regularly all within the styrene- co -butyl acrylate/Cloisite Na + matrix. However, the contact angle values for the crude copolymer film (styrene- co -butyl acrylate film) and its’ nanocomposites film (styrene- co -butyl acrylate/Cloisite Na + film) did not show any distinguished changes and were almost equal in value.

Fabrication and characterization properties of polypropylene/polycarbonate/clay nanocomposites prepared with twin-screw extruder

Abstract Polypropylene/polycarbonate (PP/PC) nanocomposites containing various proportions of the organically modified montmorillonite were prepared by extrusion and injection molding process. The morphology of PP/PC nanocomposites was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The nanocomposites with 3 or 5 wt% of nanoclay (NC) show a uniform dispersion of the NC as pointed out by two different methods, TEM and XRD. It was shown that the morphology of dispersed phase (PC) is highly dependent on the content of minor phase, which was correlated with the balance of drop breakup and coalescence. The mechanical properties have been investigated by tensile test and Izod impact test. The virgin PP/PC samples showed a reduction in impact strength and elongation at break and up to 50% increase in Young’s modulus by increase in PP content comparing with the pure PP. Investigating the effect of NC and PC content on the mechanical behavior of PP/PC nanocomposites showed increased Young’s modulus and decreased impact strength with increasing PC and NC loading. An obvious ductile to brittle behavior transition at a high content of PC or NC was supported by notched Izod impact strength experiments and SEM results.

Effects of nanoclay and its localization on the morphology stabilization of PLA/PBAT blends under shear flow

Abstract Blends of an amorphous polylactide (PLA) with 25 wt% poly[(butylene adipate)-co-terephthalate] (PBAT) containing 1 and 5 wt% Cloisite 30B (C30B) nanoclay were prepared using an internal batch mixer. Three mixing strategies were used: (S1) direct mixing of all three components, (S2) mixing C30B and PLA followed by mixing with PBAT, and (S3) mixing C30B and PBAT followed by mixing with PLA. X-ray diffraction (XRD) and transmission and scanning electron microscopy (TEM and SEM) were used to study the C30B dispersion and the blend morphology. Small amplitude oscillatory shear (SAOS) and stress growth tests were also conducted to investigate the nanocomposites and blend rheological properties and morphological stability under shear flow. With 1 wt% C30B, the nanoparticles were located at the PLA-PBAT interface for all mixing routes, which was favorable for morphology stabilization. The average PBAT droplet-diameter was reduced from 1.30 μm for the neat PLA-PBAT blend to 0.75, 0.85, and 0.70 μm for blend nanocomposites depending on the mixing strategy used. Under shearing at 0.01 s−1, droplet coalescence did not occur due to the presence of C30B at the interface of the polymer phases. On the other hand, in blends containing 5 wt% C30B, the location of the nanoparticles and the occurrence of coalescence depended on the mixing strategy used.

Effect of nanoclay on performance of neat and SBS-modified bitumen and HMA

ABSTRACTThe aim of this research was to investigate impact of nanoclay on rutting and moisture damages resistance of neat and SBS-modified asphalt binder and mixture. 4% SBS was blended with 2% nanoclay and 6% nanoclay was used and compared with neat and 4% SBS-modified asphalt binder and mixes. Results of performing rotational viscosity, dynamic shear rheometer, repeated creep recovery, indirect tensile strength, and dynamic creep tests indicated nanoclay has positive impact on rutting and moisture damages resistance of neat and modified asphalt binder.

The effects of nanoclay on thermal, mechanical and rheological properties of LLDPE/chitosan blend

Abstract The objective of this study was to prepare linear low density polyethylene (LLDPE)/chitosan/closite nanocomposites by using various concentrations of LLDPE, chitosan, and closite clay mineral. The nanocomposites were then characterized for their thermal, mechanical, and rheological properties by using different analytical techniques including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), rheological characterization, tensile strength study, and scanning electron microscopy. The TGA demonstrated that crosslinked composites are thermally more stable than non-crosslinked composites. The DSC stated that the percentage crystallinity of crosslinked composites is lower than the non-crosslinked composites. It is also observed that the increasing quantity of chitosan and closite also reduces the percentage crystallinity of the prepared nanocomposites. Rheological characterization revealed that, crosslinked composites are viscoelastic in nature and have high complex viscosities (η*) and high dynamic shear storage modulus (G′), while non-crosslinked composites showed high dynamic shear loss modulus (G″). Tensile strength of crosslinked composites was much higher than non-crosslinked composites, however elongation at break (Eb) values of non-crosslinked composites are higher than crosslinked composites. The scanning electron microscopy displayed strong adhesion between matrix-filler-interphase in crosslinked composites, while some gaps were also observed in non-crosslinked composites. As a conclusion, chitosan, closite clay, and the LLDPE based nanocomposites with improved thermal, mechanical, and rheological properties can be successfully prepared by employing a peroxide-initiated melt compounding technique.

Effect of nanoclay on the morphology of polyethylene modified bitumen

The main objective of the present work was to study the effect of nanoclay on the morphology of polyethylene modified bitumen. The bitumen was modified simultaneously with polyethylene and/or maleic anhydride grafted polyethylene and nanoclay in a high shear mixer and characterized by means of morphology and clay dispersion state. The results showed that the state of nanoclay intercalation and/or exfoliation strongly depends on the polymeric phase content, functionality of polyethylene and the mixing procedure of the components. In turn, the dispersion state of the nanoclay influentially affected the phase morphology of swelled polymeric phase. Using functionalized polyethylene and premixing of nanoclay with polyethylene phase led to improved dispersion state of nanoclay in bitumen nanocomposites. Absorption of low molecular bituminous fractions, led to decreased melting temperature of polymeric phase. The presence of nanoclay induced phase separation between polyethylene and functional polyethylene due to higher affinity of nanoclay to functional polyethylene.