MMT Nanoclay Research Articles

Flexural Properties of MMT Reinforced Unsaturated Polyester/Epoxidized Palm Oil Biobased Resin

New bio-based thermoset resin was synthesized by blending unsaturated polyester (UPE) and epoxidized palm oil (EPO) together with layered silicate nanoclay (MMT). The biobased polyester resin was processed by 1.5phr benzoyl peroxide initiator. In this study, EPO was added at 10 wt%, while the layered silicate added at 1, 1.5 and 2 phr. The MMT nanoclay was sonicated with acetone for two hours and followed by adding UPE. The MMT, acetone and UPE solution were then dried on a hot plate for 24 hours and followed by vacuum oven for 30 minutes. Then, the EPO and styrene were added to the solution. The sample was cured in an oven at 100 °C (2 hours) and followed by post curing at 160 °C (2 hours). Flexural properties of the UPE/EPO bioresin were experimentally characterized. It was found that, addition of nanoclay improved the flexural modulus of UPE resin. However, the dropped modulus of the resulted bioresin was not recovered by the addition of up to 2 phr MMT. Addition of low percentage MMT nanoclay, which was 1 phr gave a very significant improvements on the dropped flexural strength of UPE/EPO bioresin. The distribution of the MMT nanoclay in the UPE/EPO bioresin sytem was further analysed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) images.

Development of <i>Sansevieria trifasciata</i> - Carbon Fiber Reinforced Polymer Hybrid Nanocomposites

This paper presents studies on experimental values of tensile strength properties of hybrid nanocomposites were studied and compared with theoretical values. It was observed that, experimental strengths were fallen shorter than the theoretical values. Nanocomposites were fabricated by filling MMT nanoclay by weight ratio and reinforced with short sansevieria trifasciata (STF) and short carbon fibre (CF) by randomly orientation. Organically modified montmorillonite clay filled with different proportions viz.0, 1, 3 and 5 wt.% dispersed into the vinyester matrix modified system by hand lay-up technique. Natural fiber was treated by NaOH solution was brought significant performance. Tensile strength was found maximum when clay content was Clay 3wt%. In the fracture surfaces of samples were analysed by SEM analysis, in which it was observed that, increased clay viscosity played vital role in bringing the performance as the viscosity of the mixture made difficult to flow the resin. Thermal stability was significantly improved for the 5wt% sample due to the high content of silicate particles and carbon fibre content.

Development of <i>Sansevieria trifasciata</i> - Carbon Fiber Reinforced Polymer Hybrid Nanocomposites

This paper presents studies on experimental values of tensile strength properties of hybrid nanocomposites were studied and compared with theoretical values. It was observed that, experimental strengths were fallen shorter than the theoretical values. Nanocomposites were fabricated by filling MMT nanoclay by weight ratio and reinforced with short sansevieria trifasciata (STF) and short carbon fibre (CF) by randomly orientation. Organically modified montmorillonite clay filled with different proportions viz.0, 1, 3 and 5 wt.% dispersed into the vinyester matrix modified system by hand lay-up technique. Natural fiber was treated by NaOH solution was brought significant performance. Tensile strength was found maximum when clay content was Clay 3wt%. In the fracture surfaces of samples were analysed by SEM analysis, in which it was observed that, increased clay viscosity played vital role in bringing the performance as the viscosity of the mixture made difficult to flow the resin. Thermal stability was significantly improved for the 5wt% sample due to the high content of silicate particles and carbon fibre content.

On the Processing and Properties of Clay/Polymer Nanocomposites CPNC

An experimental investigation followed by fundamental characterization and discussion on the effect of nanoclay filler on the mechanical and fracture properties of polymer matrix was carried out. The study was carried out on clay/polymer nanocomposite made of High Density polyethylene (HDPE M40060) produced by Saudi Arabian company SABIC and montimorillonite MMT nanoclay (Nanomer I.34TCN) produced by Nanocore, USA. MMT nanomer I.34TCN is surface modified with organic surfactant to facilitate the bonding between nanoclay and HDPE. Current clay/polymer nanocomposite CPNC was produced by special technique of mixing, processing and molding. Samples of nanoclay, HDPE and nanocomposite were characterized by XRD, SEM and EDAX for investigating the chistillanity, distribution, desperion, intercalation, exfoliation, homogenity and defects. These aspects govern CPNC processing and bond between nanoclay and HDPE which controls the mechanical and fracture properties. Sheets of the produced CPNC were prepared for mechanical and fracture testing. Mechanical properties such as tensile strength, yield stress and elongation were tested and compared for both of pure HDPE and CPNC using non standard test specimens of flat sheets for comparison purposes. Fracture mechanics tests for checking and comparing the critical stress intensity factor due to stress concentration at the crack tips for mode I crack (KIc) were carried out using precracked non standard flat sheet specimens subjected to uniaxial uniform tensile stresses. Furthermore, standard experimental tests were conducted for both of HDPE and CPNC for investigating standard mechanical properties aspects based on ASTM D 638 using standard dumbbell-shaped specimen while for investigating standard fracture toughness standard single edge notch specimens SENB subjected bending moment due to effect of 3-point load based on ASTM D 5045 were carried out. The results showed that procedures of mixing, processing technique could produce nanocomposite with enhanced mechanical and fracture properties.

Fabrication and characterization of porous polyetherimide/montmorillonite hollow fiber mixed matrix membranes for CO2 absorption via membrane contactor

Asymmetric PEI hollow fiber mixed matrix membranes (MMMs) with improved structure and wetting resistance were fabricated via wet phase inversion method. The effects of incorporating hydrophobic MMT into polymer matrix in different loadings on the membrane properties were investigated. The membranes were characterized in terms of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), gas permeation test, hydrophobicity, wetting resistance and mechanical stability. All membranes possessed finger-like structures differing in skin layer thickness which increased with clay loading. The results revealed that the MMMs have significantly smaller pore size, higher porosity, hydrophobicity, LEPw and mechanical stability than plain PEI membrane. The membranes were further characterized by CO2 absorption test via contactor system using distilled water as absorbent and pure CO2 as solute gas. The results showed that the CO2 absorption performance increased with addition of MMT nano-clay. The membrane containing 1wt% MMT recorded the highest absorption flux of 2.35×10−3molm−2s−1 at the liquid velocity of 3ms−1, almost 135% higher than the flux of plain membrane at the same velocity. Comparatively, the flux of MMM was superior to several in-house made and commercial membranes.

Mechanical, Thermal, and Microstructural Analysis of Polyvinyl Alcohol/Montmorillonite Nanocomposites

Structural biomaterials such as nacre, bone, and fish scales possess unique structures that have hierarchical spatial configurations, which provide excellent mechanical properties when compared to their individual constituents. These observations have been the motivation for designing and characterizing bioinspired materials with high strength, high stiffness, and corrosion‐resistant properties while at the same time being environmentally friendly. It has been demonstrated that polymer‐clay nanocomposites can simulate the behavior of nacreous biomaterials such as abalone shell. Mechanical, thermal, and microstructural analyses characterized solution‐cast polyvinyl alcohol (PVA)/montmorillonite (MMT) nanocomposite properties over compositions ranging from the neat polymer to 25% volume fraction of MMT nanoclay. Uniaxial tensile experiments were performed at displacement rates of 1 mm/min and 50 mm/min. Strength values are similar to those shown by nacre and represent a homogeneous dispersion of the MMT in the polymer matrix. Strength‐to‐weight ratios are similar to many structural metals.

Reinforcing Effect of Montmorillonite Nanoclay on Mechanical Properties of High Density Polyethylene Nanocomposites

In recent years, many researches focused on the polymer materials to study the characteristics and to enhance the mechanical properties of the nanocomposites in order to understand the factors which lead to the desired dispersion of nanoclay in the polymer matrix. The samples used in this work were prepared through melt compounding, using high-density polyethylene and organo-modified clay of montmorillonite (MMT). During manufacturing of MMT/HDPE nanocomposites, a silane modifier and polyethylene grafted with maleic anhydride (compatibilizer) were added to get good surface finish and to act as bonding agent respectively. In addition, the compatibilizer will help in attaining better intercalation. Using a Plastograph-Mixer through twin-screw extruder, the high density polyethylene and different weight percentages (0, 1, 2, 3, 4 wt. %) of MMT are mixed and subsequently the composite is produced in the form of solid material. ASTM standard specimens for various tests are produced using injection molding machine with respective dies. The prepared experimental specimens for various tests like tensile, flexural, impact and shore-hardness are tested for its respective strengths. From this investigation, it is concluded that the addition of MMT nanoclay in HDPE has significantly influenced the mechanical properties of the composites.

Synthesis and evaluation of swelling kinetics of electric field responsive poly(vinyl alcohol)‐g‐polyacrylic acid/OMNT nanocomposite hydrogels

Novel electro‐responsive nanocomposite hydrogels were prepared by the radical graft polymerization reaction of partially neutralized acrylic acid on poly(vinyl alcohol) and organically modified MMT nanoclay (OMMT) using glutaraldehyde as a crosslinker and potassium initiator. The structures of the hydrogels were confirmed by using Fourier transform infrared, X‐ray diffraction, and scanning electron microscopy study. The nanocomposite hydrogels were characterized by evaluating such molecular weight between crosslinks, (Mc) crosslinking density (ρ), and mesh size (ξ). The effects of various parameters on the swelling behavior of the hydrogels were studied. The thermogravimetric analysis indicated that introduction of clay resulted in an increase in thermal stability. Finally, the electric stimuli responsive measurement indicates the bending of hydrogel toward the cathode in an aqueous solution of NaCl. POLYM. COMPOS., 36:34–41, 2015. © 2014 Society of Plastics Engineers

Flame retardant polyamide 6/nanoclay/intumescent nanocomposite fibers through electrospinning

Flame retardant polyamide 6 (nylon 6) nanocomposite nanofibers containing montmorillonite clay (MMT) platelets and intumescent non-halogenated flame retardant (FR) additives were processed by electrospinning. Different methods of mixing nano fillers before electrospinning were explored and compared. It was found that high loadings of nanoclay particles affected the electrospinnability of the nanocomposite material. Good dispersion and exfoliation of nanoclay platelets within individual nanofibers was verified by transmission electron microscopy. The degradation temperature of nanocomposite samples was lower than pristine nylon 6 samples. However the degradation of all nanocomposite formulations was overall slower. Moreover, the difference in residual char weight after decomposition was significant. Microscale combustion calorimeter results show that FR particles played a major role in reducing flammability of the material in both solution- and melt-compounded samples, while MMT nanoclay was effective in improving char residue and in reducing flammability in high-shear melt premixed samples.

Effects of Surface Treatments of Montmorillonite Nanoclay on Cure Behavior of Diglycidyl Ether of Bisphenol A Epoxy Resin

Diglycidyl ether of Bisphenol A (DGEBA) based SC-15 epoxy resin was modified with three different commercially available montmorillonite (MMT) nanoclay: Nanomer I.28E and Cloisite 10A and 30B. Cure behavior of nanocomposites was studied using a variety of techniques. Primary focus of this study was to investigate influence of different surface modifications of MMT nanoclay on rheological properties and cure behavior of SC-15 epoxy resin. By adding MMT to SC-15 epoxy resin, chemistry of the epoxy is altered leading to changes in rheological properties and ultimately enthalpy and activation energy of reactions. Addition of Nanomer I.28E delayed gelation, while Cloisite 10A and 30B accelerated gelation, regardless of the curing temperature. Activation energy of reaction was lower with the addition of Nanomer I.28E and Cloisite 10A and higher for Cloisite 30B compared to neat SC-15 epoxy composite.

Effects of Coagulation-Bath Temperature And Montmorillonite Nanoclay Content on Asymmetric Cellulose Acetate Butyrate Membranes

AbstractA major problem with polymeric membranes is low hydrophilicity and consequently a tendency to fouling. Preparing composite membranes is one way to improve the properties and performance of the neat membrane. In the present study, the effects of coagulation-bath temperature (CBT) and the hydrophilic nanoclay concentration of montmorillonite (MMT) on the morphology and performance of asymmetric cellulose acetate butyrate (CAB) membranes were investigated. The membranes were prepared via phase inversion induced by immersion precipitation in a water-coagulation bath. The morphology of the membranes prepared was studied by scanning electron microscopy (SEM). The permeation performance of the membranes prepared was studied by experiments using pure water and bovine serum albumin (BSA) solutions as feeds. The results showed that the membrane thickness and pure water flux (PWF) were increased by adding up to 2 wt.% MMT nanoclay to the casting solution. These two parameters decreased with further addition of MMT, however. In addition, the results obtained in the case of filtration of BSA solution indicated that the addition of MMT in the casting solution increased permeate flux and reduced BSA rejection slightly. Furthermore, increasing the MMT nanoclay concentration in the casting solution increased pure water flux recovery and consequently decreased the fouling. Decreasing the CBT in the presence of MMT during membrane preparation resulted in the formation of a more porous structure and consequently increased the flux and simultaneously decreased the BSA rejection.

Synthesis of CarAlg/MMt nanocomposite hydrogels and adsorption of cationic crystal violet

CarAlg/MMt nanocomposite hydrogels composed of kappa-carrageenan (Car) and sodium alginate (Alg) biopolymers were synthesized by incorporation of sodium montmorillonite (Na-MMt) nanoclay. Acrylamide (AAm), methylenebisacrylamide (MBA), and ammonium persulfate (APS) were used as monomer, crosslinker, and initiator, respectively. The structure and morphology of nanocomposites were characterized by XRD, SEM, and TEM techniques. The XRD results showed exfoliated MMt nanoclay and exfoliation of MMt was confirmed by TEM graph. The resulting nanocomposites were evaluated to remove cationic crystal violet (CV) dye from water. According to data, the adsorption capacity of nanocomposites was enhanced as the clay content was increased. The experimental data were analyzed according to both Langmuir and Freundlich models and experimental maximum adsorption capacity was obtained 88.8mgg−1. By studying the effect of pH on the dye adsorption capacity of nanocomposites, it was revealed that the adsorption capacity of nanocomposites was enhanced at acidic pHs as the Na-MMt nanoclay and kappa-carrageenan components were increased.

Study of the simultaneous effects of MMT nanoclay and hydrophobically modified ethoxylated urethane (HEUR) on viscoelastic and steady shear properties of water-based acrylic resins

The storage stability of montmorillonite/acrylic resin was studied via rheological characterizations. The Na+–MMT nanoclay and a water-based acrylic resin were used for the preparation of different suspension samples. The effect of an associative polymer such as hydrophobically modified ethoxylated urethane (HEUR) in the mixture was also investigated. The result showed that the existence of an associative polymer has an influence on the stability and zero-shear viscosity of the system. In order to determine the behavior of this system under long-term storage, various rheological characterizations such as frequency sweep and rate sweep measurements were carried out. The results showed that adding the montmorillonite nanoclay and HEUR to the acrylic resin causes short- and long-term stabilities of suspensions microstructure. The required stability, a better flow, and a better structure were achieved, respectively, upon addition of an associative polymer, addition of MMT–Na+, and flow cessation.

Effects of chemical modifications and MMT nanoclay addition on transport phenomena of naturally woven coconut sheath/polyester nanocomposites

Studies on the behavior of molecular transport properties such as thermal conductivity, gas permeability, volume and surface resistivity have been carried out for the naturally woven coconut sheath (CS) fiber reinforced composites with the addition of nanoclay and chemical treatment of fiber. The compression molding technique was used to fabricate the coconut sheath/clay reinforced hybrid composites. The morphological studies such as X-ray diffractogram (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been carried out for polyester nanocomposites and coconut sheath fiber. The decreased gas permeability, thermal conductivity and volume and surface resistivity have been observed with increasing the weight percentage of nanoclay in polyester matrix. In chemical modifications, the alkali and silane treated coconut sheath reinforced composites have shown great influence on the transport properties due to the increasing hydrophilic nature by the topographical changes at the fiber surface. Dielectric strength has also been reported in this paper for all types of composites. Infra-red (IR) spectra have also been taken to study the physical and chemical structural changes of treated coconut sheath.

Influence of MMT nanoclay on impedance spectroscopy analysis of naturally woven coconut sheath/polyester hybrid composite

AbstractIn this work, the impedance spectroscopy study has been carried out for the naturally woven coconut sheath fiber reinforced composite with the effect of adding different weight percentages of montmorillonite nanoclay and chemical activation of fiber. The dispersion mechanism of nanoclay with polyester, and the modification of the fiber surface have been studied by using X–ray diffractogram, transmission electron microscope and scanning electron microscope respectively. Infra‐red spectra have also been taken to study the reactive compounds of treated fibers. The impedance spectrum shows significant improvement in A.C. conductivity, dielectric constant and loss tangent values by the fiber modification, using alkali and silane treatments, due to the structural topography changes at the fiber surface. The highest dielectric strength was found in alkali‐treated coconut sheath/polyester composite due to increase in orientation polarization by the absorption of moisture content at fiber surface. The addition of different weight percentages of nanoclay with coconut sheath in all the treated conditions shows significant changes in the dielectric properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Characterization of Extruded Thermoplastic Starch Reinforced by Montmorillonite Nanoclay

The purpose of this study was to understand how the montmorillonite (MMT) nanoclay influences physical and mechanical properties of thermoplastic starch (TPS), which was produced by a conventional extrusion procedure. MMT nanoclay was added at 0, 4, and 8 % (w/w) concentrations. Transmission electron microscopy (TEM) showed most MMT platelets existed in tactoid structure in the starch matrix. In addition, FTIR spectra indicated TPS/MMT nanocomposites kept chemically stable after the extrusion. Tensile strength (TS) was about 7.0 MPa, while elongation-at-break (E) and elastic modulus (EM) were about 52 % and 32–41 MPa, respectively. Moisture sorption behaviour of the samples was well described by GAB and BET models. Thermal property tests exhibited the glass transition temperature (T g ) of the nanocomposites decreased with increasing MMT from 0 to 8 %, indicating MMT nanoclay had a plasticization effect.

Thermorheological complexity of a dynamically asymmetric miscible blend: the improving role of Na+-MMT nanoclay

The influence for the minor amount of sodium montmorillonite (Na+-MMT) nanoclay on the thermorheological complexity of a miscible blend of 20 wt% poly(ethylene oxide) (PEO) in poly(methyl methacrylate) (PMMA) is studied. The dispersion of Na+-MMT in the PEO/PMMA is assessed via X-ray diffraction. The empirical principle of time-temperature superposition is found to be partially restored in the case of blend nanocomposite, whereas it fails for the neat PEO/PMMA blend. The relaxation times of each component are determined from the oscillatory shear rheometry data in the form of a monomeric friction coefficient. The chain dynamics of components is coupled in the presence of hydrophilic nanoclay, which preferentially adsorbs PEO. The self-concentration model of Lodge and McLeish successfully describes the temperature dependence of the PMMA monomeric friction coefficient in both the neat and blend nanocomposite in regards to the temperature range studied. Open image in new window

Properties of Sago Starch-Nanoclay Biocomposites Film

This paper reported on properties of sago starch that was compounded with montmorillonite (MMT) nanoclay to form biodegradable composites film. The film was fabricated via film casting method with glycerol as a plasticizer. The investigated biocomposites film was prepared at starch-glycerol/MMT weight fraction of 90/10, 85/15, 80/20 and 75/25. The physical properties of the film, namely thickness and density were studied and results show that incorporation of nanoclay as filler affects the biocomposites physical properties. Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyze the film’s morphological properties and chemical characteristics, respectively. SEM shows that less clay content in the film produces homogenous phase and well dispersed of clay platelets within the starch matrix. FTIR summarizes that MMT nanoclay is able to form hydrogen bonding with starch.

Formation of novel and crack free nanocomposites based on sol gel process for corrosion protection of copper

Silica based nanocomposites have been developed on copper based on the sol gel process using phenyltrimethoxysilane (PTMS) and sodium montmorillonite (MMT) nanoparticles. Protective properties of the prepared coating and also its characterization were examined by different methods including potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Fourier Transform Infrared (FTIR) and scanning electron microscopy (SEM). The results indicated that the application of PTMS sol gel coating provided a greater corrosion protection in comparison with bare copper substrate. Crack free sol gel coatings were obtained after the addition of nanoclays. Also, protective properties of the coatings improved after the addition of MMT nanoclay in certain concentrations. The hydrophobic properties of the sol gel nanocomposites have been examined by the contact angle measurements.

Ultrasonic treatment and synthesis of sugar alcohol modified Na+-montmorillonite clay

Na+-montmorillonite clay (generally referred to as MMT) is very useful for reinforcing polymeric matrix at very low concentrations (typically, 2–5% wt). These clay particles are typically exfoliated before they can demonstrate the significant gains in heat deflection temperature, modulus, and elongation properties. In the case of hydrophilic biopolymer based matrices, such as carbohydrates and chitosan, exfoliating these nanoclay particles needs greater attention because the exfoliation is typically carried out using hydrophobic oligomers through ion-exchange. This study reports a new method of synthesizing completely hydrophilic MMT-assemblages using hydrophilic plasticizers for biopolymers. We used sugar alcohols (glycerol, xylitol with 3 and 5 hydroxyl groups) and polysaccharide maltodextrin to exfoliate the MMT. Sonication was conducted for MMT nanoclay and plasticizers at different weight ratios. It was confirmed that all plasticizer/modifier led to expansion of MMT gallery spacing (d-spacing) and the change in d-spacing could be related to the molecular structure of the plasticizer. Meanwhile, the extent of exfoliation was maximum with maltodextrin (fully exfoliation with 1:10 and 1:20 ratio of MMT:plasticizer) across all test samples and interestingly, glycerol and xylitol samples quickly established within the MMT galleries and exhibited minimal influence with further increase in relative concentrations.