Effect Of Nanoclay Loading Research Articles

Development of novel models for fatigue life assessment of natural rubber/styrene‐butadiene rubber/nanoclay nanocomposite

AbstractIn the present work, multiple regression models are established for assessing the fatigue life of nanoclay nanocomposites comprising natural rubber (NR) and styrene‐butadiene rubber (SBR). Quadratic (for two factors) and reduced cubic (for three factors) regression models have been applied to create the NR/SBR/nanoclay durability models, and the goodness of fit, homoscedasticity, and normality of the models were evaluated. Also, an analysis of the influence factors on the fatigue life of NR/SBR/nanoclay nanocomposites was done. Various factors were chosen for the investigation: strain amplitude, nanoclay loading, and test frequency. By creating the effects model, the main effects and the interactions of each factor on the fatigue life of the nanocomposites were considered. A statistical analysis of the quadratic model revealed that the strain amplitude has the most significant effect on the fatigue life of rubber samples. The variance analysis of the reduced cubic model showed that the nanoclay loading and the test frequency have the most negligible effect on the rubber samples' fatigue life, respectively. Despite the significant main impact of the studied factors, the 2‐way interaction, as well as the 3‐way interaction of the variables, was not effective in the reduced cubic fatigue life model.Highlights Multiple regression models are used for the evaluation of the fatigue life. The effect of nanoclay loading, the strain, and the test frequency are studied. Statistically fatigue life prediction model of nanocomposite is created. Nanoclay loading has the most effect on fatigue life.

Evaluation of the effectiveness of poly (phenyl sulfone) / nanoclay mixed matrix membranes for carbon dioxide/methane separation

Poly (phenyl sulfone) (PPSU) is a recently introduced poly (aryl sulfone) polymer that has attracted much attention for membrane fabrication. PPSU could fabricate both porous and non-porous membranes. Intrinsic gas permeability of pure PPSU is low, but it has good selectivity for CO2/CH4 separation. Therefore, this study aimed to investigate the effect of adding a layered nanoclay material to PPSU on CO2 permeability and CO2/CH4 selectivity. The fabricated membranes were characterized by FTIR, FESEM, XRD, DSC, EDS, Contact angle, gas solubility, and gas permeability. The permeability of each gas was measured by the constant volume-variable pressure method, and ideal selectivity was determined. The effect of nanoclay loading (1-3 wt.%) and feed pressure (2-8 bar) on the gases' permeability and CO2/CH4 selectivity was investigated at a constant temperature of 27 ± 2°C. The results showed that the addition of the nanoclay to PPSU has a considerable effect on CO2 permeability (up to 52% increase) while CO2/CH4 selectivity remains nearly unchanged or slightly decreases (down to 6%). Solubility measurement results revealed that adding the nanoclay to the PPSU polymer increases the solubility selectivity by 22%, while the diffusivity selectivity is decreased by 23%, revealing the formation of an intercalated morphology, confirmed by XRD analysis.

Tribological properties of layered silicate nanoparticle filled acrylonitrile butadiene styrene (ABS) nanocomposite produced using 3D printing

ABSTRACT Tribological properties of layered silicate nanoparticle-filled acrylonitrile butadiene styrene (ABS) nanocomposite have been investigated. The nanocomposite spur gear was developed by infusing different weight percentages of nanoclay (0–2 wt.%) on each printed ABS layer using an additive manufacturing 3D procedure. A square panel of 12 layers with varying weight percentages of nanoclay was created using a 3D printer. The effect of nanoclay loading and different sliding distances (122.5 m, 800 m, and 2000 m) on the wear and friction properties conducted at parallel and transverse layer orientation of nanocomposite were investigated. The results show that the loading nanoclay improved tribological properties of 3D printed ABS nanocomposite and spur gear with 2 wt.% nanoclay offered a low wear rate and adequate coefficient of friction irrespective of the abrasion layer orientation. SEM images showed a uniform homogeneous dispersion of nanoclay strongly bonded with the matrix, which produced an interlocking layered structural formation resulting in less wear rate and a stable coefficient of friction. These tribological properties suggested materials that may be positively used for gear applications.

Preparation of polyHIPE nanocomposites: Revealing the influence of experimental parameters with the help of experimental design approach

AbstractControlling the morphology and physical properties of poly(high internal phase emulsion)s (polyHIPEs) is critical for the development of well‐defined porosity with improved mechanical properties for industrial applicability. Therefore, in this study, experimental design methodology was used to prepare polystyrene based polyHIPE nanocomposites. A surface modified nanoclay was used to reinforce the chalky and brittle polystyrene, and the effect of nanoclay loading was investigated studiously. Emulsion stability has not been compromised due to the presence of modifier groups on the nanoclay surface. A total of 36 samples were produced according to the experimental design matrix. The relationship between the emulsion preparation conditions and final polyHIPE properties including cavity size, interconnected pore size, compression modulus, specific surface area, average pore volume, skeletal density, and foam density were determined by using a statistical software for a 95% confidence level (α = 0.05). In this way, in addition to deriving the empirical model equations for each property, the mutual and synergistic interactions of experimental parameters were also determined.

Processing and characterization of 3D-printed nanoclay/acrylonitrile butadiene styrene (abs) nanocomposite gear

In this study, the possibility of producing layered silicate-reinforced acrylonitrile butadiene styrene (ABS) using additive manufacturing procedures was investigated. In particular, this investigation presents novel methods for making nanoclay-infused acrylonitrile butadiene styrene composite spur gear. The gear was developed by introducing different weight percentages of nanoclay (0–5 wt%), on each acrylonitrile butadiene styrene layer. A square panel of 6 layers with varying proportions of nanoclay was fabricated using a 3D printer. The effect of nanoclay loading on the mechanical properties such as impact, tensile, flexural, and DMA of spur gears created using pure acrylonitrile butadiene styrene and nanoclay-infused nanocomposite was investigated and compared. The strength of the developed spur gear varies with different loading of nanoclay. The results that the spur gear, with 2 wt% nanoclay, offered superior properties. The micrographs showed the dispersion of nanoclay strongly bonded with the matrix, resulting in improved strength and stiffness. The improvement in mechanical properties depicts the effectiveness of additive manufacturing procedure with an enormous benefit for the mass production of gears of different types.

Enhancing Properties of Cured NR/PVA Blends Using Glutaraldehyde as a Crosslinking Agent: Effect of Nano-Clay Loading

A novel and inexpensive method to vulcanize natural rubber (NR) was successfully developed and reported in our previous work. NR can be easily vulcanized using glutaraldehyde (GA) at low temperature without adding any specific activators. However, there is some limitation (i.e., poor film formation and properties) to apply as many product items. Therefore, the main objective of this work is to improve the properties and film formation of this cured system. The effect of loading levels of nano-clay on the properties of GA cured NR/PVA blends has been investigated. Mechanical, thermal and morphological properties were characterized. From the overall characterization, cured NR/PVA blends with 1 phr of nano-clay exhibited the highest tensile strength, elongation at break and hardness of 8.02 MPa, 690% and 62.4 shore A, respectively. Enhancing in thermal stability of the sample was confirmation by shifting of degradation temperature based TGA technique. The experimental results reveal that the properties and film formation of this system can be developed with the proper additives in the preparation. From obtained knowledge, it is interesting due to it can be applied for various industrial applications with eases of producing at low temperature and cost.

Synthesis and investigation of the ablation performance and the thermal behavior of the polyacrylonitrile-based carbon-polymer-layered silicate composites

The effect of nanoclay loading on the crystalline structure and the thermal properties of the polyacrylonitrile-based carbon-polymer-layered silicate nanocomposites was investigated. The modified Montmorillonite with 0–7.5 wt% was distributed by a melt-mixing method in a phenolic matrix and a polyacrylonitrile-based carbon cloth was used as the reinforcement. The composite was prepared by a manual layout method and cured in an autoclave at 160 °C for 4 h. The dispersion of the clay layers in the resin was determined by XRD and TEM studies. The oxyacetylene flame and cone calorimetric tests were used to investigate the ablation performance and the thermal behavior of the nanocomposites. The results showed that the d-spacing of nanocomposites was doubled due to nanoclay loading. The oxyacetylene test showed that nanoclay addition had a better insulation effect. Also, the heat release rate (HRR) of heat was decreased up to 30% by adding the layered silicates.

Investigating the diffusional behaviour of Irganox®1076 antioxidant in HDPE/Cloisite®15A nanocomposite‐based food contact packaging films: Effect of nanoclay loading

In this research work, the prediction of the diffusion coefficient (Dp) of Irganox® 1076 (Ir‐76) antioxidant in HDPE‐based food contact packaging films was carried out. The diffusion of this additive was studied both, in neat HDPE film and in HDPE nanocomposites films made of HDPE matrix filled with 1, 3, and 5 wt% of a commercially available organoclay (Cloisite®15A). The diffusion experiments were carried out by using the Roe's method on films consisting of a stack of several polymer films having a total nominal thickness of 120 ± 01 μm. Diffusion coefficients were determined in the temperature range 80°C to 100°C according to the second Fick's law by measuring the evolution of the Ir‐76 concentration in the films by means of Fourier transform infrared (FTIR) spectroscopy analysis. The results indicated that the diffusion coefficient of Ir‐76 in HDPE films decreased with the addition of the organoclay, and a maximum reduction of 78% (at 23°C) in the diffusion rate of the Ir‐76 was observed at an optimum filler content of 3 wt%, thus making these films attractive for the plastic packaging industry.

Effect of Nano Clay on Mechanical Behavior of Bamboo Fiber Reinforced Polyester Composites

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. The present study aimed to investigate the effect of Nano clay loading as filler on the mechanical properties of the bamboo fiber yarn reinforced polyester composite. Five different types of composite specimen were prepared with Nano clay loadings of 0 to 4 % weight fraction using hand lay-up technique. It was observed that the composite sheet with 1 wt % nano clay content exhibited the optimized tensile and flexural strength. However the mechanical properties tend to decrease with addition of nano clay content from 2 to 4 wt %. In spite of that the values of mechanical properties with 2 and 3 wt % nano clay content is higher than 0 wt % nano clay content.

Effect of nanoclay loading on the thermal decomposition of nanoclay polyurethane elastomers obtained by bulk polymerization

Thermoplastic urethane (TPU) nanocomposite was prepared successfully by dispersion at high shear stress of the nanoclay in polyol and further bulk polymerization. Our results from DSC studies showed an increase in decomposition temperature when nanoclay was loaded at 3,5% on elastomeric PU made from TDI, PTMEG and BDO, while not when nanoclay content was lower (1,5%). The exotherms at 370-375°C could be adscribed to the decomposition of the hard segments according to previous work.

MDF dust/PP composites reinforced with nanoclay: Morphology, long-term physical properties and withdrawal strength of fasteners in dry and saturated conditions

In this study, effect of nanoclay loading (0%, 2%, 4% and 6%) on long-term physical properties and withdrawal strength of fasteners before and after saturation of polypropylene/MDF dust composites was investigated. Sanding dust of medium density fiberboard (MDF) was used as lignocellulose material and polypropylene as the thermoplastic material. The results showed that long-term water absorption (WA) and thickness swelling (TS) was found to decrease as the nanoclay loading increased. Also, WA and TS both were increased with increasing MDF dust content. Maximum withdrawal strengths of fasteners (screws and nails) were obtained in the samples reinforced with 2% weight percentages nanoclay. Withdrawal strengths of fasteners in saturated state toward unsaturated state were decreased. In fact, exposure to water for long term was resulted in significant reduction in withdrawal strengths of fasteners due to the degradation of the fiber/matrix interface. The morphological analysis of wood–plastic composite (WPC) samples was carried out by field emission scanning electron microscopy (FE-SEM) to study the fiber/matrix adhesion interactions. X-ray diffraction (XRD) showed the formation of intercalated nanostructure.

Kinetic study of in situ normal and AGET atom transfer radical copolymerization of n–butyl acrylate and styrene: Effect of nanoclay loading and catalyst concentration

AbstractThe effect of clay nanolayers and catalyst concentration on the kinetics of atom transfer radical copolymerization of styrene and butyl acrylate initiated by activators generated by electron transfer (AGET initiation system) or an alkyl halide (normal initiation system) was studied. Monomer conversion was studied by attenuated total reflection–Fourier transform infrared spectroscopy, and also proton nuclear magnetic resonance (1H NMR) spectroscopy was utilized to evaluate the heterogeneity in the composition of poly(styrene‐co‐butyl acrylate) chains. A decrease in the copolymerization rate of styrene and butyl acrylate in the presence of clay platelets was observed since clay layers confine the accessibility of monomer and growing radical chains. Considering the linear first‐order kinetics of the polymerization, successful AGET and normal atom transfer radical polymerization (ATRP) in the presence of clay nanolayers were carried out. Consequently, poly(styrene‐co‐butyl acrylate) chains with narrow molecular weight distribution and low polydispersity indices (1.13–1.15) were obtained. The linearity of ln([M]0/[M]) versus time and molecular weight distribution against conversion plots indicates that the proportion of propagating radicals is almost constant during the polymerization, which is the result of insignificant contribution of termination and transfer reactions. Controlled synthesis of poly(styrene‐co‐butyl acrylate)/clay is implemented with the diminishing catalyst concentration of copper(I) bromide/N,N,N′,N′′,N′′‐pentamethyl diethylene triamine without affecting the copolymerization rate of normal ATRP. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 789–799, 2012

Effect of Nanoclay Loading on the Thermal and Mechanical Properties of Biodegradable Polylactide/Poly[(butylene succinate)-co-adipate] Blend Composites

Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0 to 9%. Small angle X-ray scattering patterns showed slightly better dispersion in PBSA than PLA, and there was a tendency of the silicate layers to delaminate in PBSA at low clay content. Thermal analysis revealed that crystallinity was dependent on the clay content as well its localization within the composite. On the other hand, thermal stability marginally improved for composites with <2 wt % clay content in contrast to the deterioration observed in composites with clay content >2 wt %. Tensile properties showed dependence on clay content and localization. Composite with 2 wt % clay content showed slight improvement in elongation at break. Overall, the optimum property was found for a composite with 2 wt % of the organoclay. This paper therefore has demonstrated the significance of the clay content and localization on the properties of the PLA/PBSA blends.

Characterization of HDPE/MMT-Based Nanocomposites

A series of HDPE/MMT nanocomposites with different proportions of compatibilizers, PE-g-MAH (AC573A and 5TP409/E) were prepared in a counter rotating twin screw extruder. The effect of nanoclay loading, compatibilizer type and amount was examined. The work was carried out using a specific grade of HDPE recommended for blow-moulding applications and modification of the same by blending with selected polymer and nanofiller to achieve the desired properties. The composition containing higher percentage of nanoclay showed improvement in mechanical properties. About 17% in tensile modulus and about 20% increase in flexural modulus were observed with high-viscous compatibilizer. The dispersion behaviour of nanoclay in PE matrix was studied using X-ray diffraction and transmission electron microscopy. It was clear from WXRD that in all nanocomposite samples, the peaks were shifted to lower 2 values implying that the d-spacing increases and that intercalation occurred. Low molecular weight compatibilizer PE-g-MA resulted in better intercalation than high molecular weight compatibilizer. It was observed that in the case of 5% AC573A loading, there was slight decrease in d-spacing value which indicated that some exfoliation also occurred in nanocomposite. Nanocomposite containing PE-g-MAH is higher concentration gives better dispersion than at low concentration. TEM results show that PE-g-MAH (AC573A) at 5% loading is more efficient as compatibilizer (not many aggregates seen) than other compositions.

Effect of nanoclay on the mechanical and damping properties of aramid short fibre‐filled styrene butadiene rubber composites

AbstractThe effect of nanoclay loading on the alteration of tensile and dynamic mechanical properties of aramid short fibre‐filled styrene butadiene rubber composites was investigated. In all the composites, 20 phr of N330 black was used. Dynamic mechanical thermal analysis was used to investigate the viscoelastic damping at lower dynamic strains. Compressive hysteresis was evaluated to characterize higher strain static damping properties. Matrix–fibre interaction and filler distribution were investigated using morphological analyses. Matrix–filler interface, estimated by the half height width of the tan δ peak, plays a major role in energy dissipation. The matrix–fibre interaction parameter shows a similar trend with low strain tensile stress values. Nanoclay addition to the composites leads to improved elongation at break and frequency damping properties. Compressive hysteresis reflects no improvement of hysteresis with nanoclay loading. Dynamic storage moduli, matrix–fibre interaction parameter and energy dissipation properties of the short fibre‐filled composites are negatively affected by nanoclay addition. However, ultimate elongation is improved markedly on nanoclay addition. In respect of tensile strength and elongation at break values, two composite samples (KF5NC10 and KF10NC10) offer optimum properties. Copyright © 2009 Society of Chemical Industry