Nanoclay Modification Research Articles

Effect of Nanoclay Modification on Properties of Natural Rubber Nanocomposites Using Zinc Compound

This study investigates the effect of nanoclay modification on the properties of natural rubber (NR) nanocomposites using zinc stearate (ZS) and di(hydrogenated tallow) dimethylammonium chloride (DHDT). The aim is to enhance the compatibility of modified nanoclay (NC) and NR molecules for determining cure characteristics, mechanical properties, and morphologies. The effect of unmodified and modified NC as the secondary filler was studied using the 10 phr NC regarding the received properties of the silica-based composites. Results indicated that the NR composites with modified NC exhibited a significant improvement of 32.06% estimated crosslink density, 16.6% tensile strength, 30.1% Payne effect together with the production time of 3.9 min relative to the composites with unmodified NC. This related to the dispersion and distribution degree of the NC and it suggests that the modification of nanoclay with ZS and DHDT can positively impact to the NR nanocomposites, enhancing their mechanical performance and processing characteristics. Keywords: Modified nanoclay, Natural rubber, Nanocomposites

Improving the performance of CFRP-reinforced concrete cylinders in sulfate-laden environment through nanoclay modification of epoxy resin

The durability of epoxy-concrete interface is a crucial factor for practical application of externally bonded fiber-reinforced polymer (FRP) retrofit systems, particularly when the strengthened structure is subjected to severe environmental conditions. Given the demonstrated potential of nanoclays in enhancing engineering performance of polymers, this work assesses the beneficial effect of organic montmorillonite (OMMT) nano-modification of epoxy resin on the axial compressive properties of FRP-reinforced concrete under a 10 wt% sodium sulfate wet/dry (W/D) cycling environment. Three types of concrete samples were fabricated and tested: plain concrete cylinders, CFRP-reinforced concrete cylinders using unmodified vs. OMMT-modified epoxy resin as the adhesive, respectively. The optimal dosage of OMMT was determined to be 2 wt% through tensile and lap shear tests, as well as microscopic characterization of the fractured cross-section of the molded resin samples. This optimal dosage of OMMT allows the epoxy adhesive to achieve the highest values in the tensile strength (90.4 MPa), lap shear strength (80.0 MPa), Tg (280.5°C) and water contact angle (115.1°). In the fracture section of epoxy resin with a 2 wt% OMMT, multiple microcracks developed and the OMMT nanoplatelets were well dispersed in the epoxy matrix. The laboratory testing program explored various W/D cycle periods. The experimental results indicate that the OMMT-modified epoxy resin significantly improved the mechanical properties and deformation resistance, altered the failure mode, and effectively delayed the strength degradation of the protected concrete. After 150 W/D cycling days, the OMMT-modified CFRP-confined concrete samples maintained their ductility coefficient and axial compressive strength at 3.58 and 123.5 MPa, respectively, 12.6 % and 9.1 % better than the common CFRP-confined samples. Combining these results with the residual axial compressive strength ratio, we propose an improved design model for calculating the axial compressive strength of CFRP-retrofitted concrete structures in sulfate-laden environments. This study demonstrates the beneficial role of OMMT in enhancing the epoxy adhesive and provides insights into the reinforcement of concrete structures by externally bonded CFRP in sulfate-rich environments.

Unravelling the thermal behavior and kinetics of unsaturated polyester resin supplemented with organo-nanoclay.

The integration of nanoclays within polymeric systems to develop high-performance materials is an emerging research field that has garnered significant attention. In this context, an organically modified montmorillonite (OMMT) is utilized as a reinforcing agent for unsaturated polyester resin (UPR) with loads of 1%, 3%, and 5 wt%. The modification of montmorillonite nanoclay (MMT) using a quaternary ammonium compound is performed through an effective repetitive modification process under reflux conditions. The curing behavior of the unsaturated polyester resin containing organically modified clay catalyzed with methyl ethyl ketone peroxide (MEKP) initiator and promoted by cobalt naphthenate accelerator is investigated using dynamic differential scanning calorimetry (DSC) followed by kinetic analysis using isoconversional methods. The dynamic DSC curing curves showed a bimodal exothermic peak, where two independent reactions, namely, redox and thermal decomposition of the initiator occurred. In this study, novel insights into the curing reaction of the studied UPR and UPR/OMMT systems have been revealed through the application of the Trache-Abdelaziz-Siwani (TAS) and Sbirrazzuoli (VYA/CE) isoconversional methods. These methods have enabled the elucidation of the intricate mechanisms and phenomena that impact the curing reaction, including the dilution effect in the redox reaction and the diffusion phenomenon at the end of the thermal decomposition reaction. The incorporation of nanoclay into unsaturated polyester resin (UPR) resulted in a reduction in the activation energy for both the redox and thermal reactions. Specifically, the energetic barrier decreased from 93.85 and 101.58 kJ mol-1 for pristine UPR to 60.71 and 72.93 kJ mol-1 for UPR/OMMT-5 in the redox and thermal reactions, respectively. The addition of OMMT caused a significant decrease in the pre-exponential factor. The values of UPR/OMMT-5 were 2.75 × 105 and 5.50 × 106 for the redox and thermal decomposition reactions, respectively, compared to 1.41 × 1012 and 5.13 × 1013 for UPR. The thermogravimetric analysis demonstrated that UPR/OMMT systems were more stable than UPR.

Integrating Structural and Thermodynamic Mechanisms for Methanol Intercalated Kaolinite Nanoclay: Experiments and Density Functional Theory Simulation.

Methanol intercalated kaolinite (Kaol) plays an important role in the intercalation, exfoliation, and organic modification of kaolinite nanoclay. However, the evolution of the layer structure of Kaol and its thermodynamic stability during the methanol intercalation process have not been clarified at the atomic level. Here, by combination of density functional theory (DFT) calculation and experimental characterizations, the interlayer bonding, structure evolution, and energetics from dimethyl sulfoxide (DMSO) intercalated Kaol to methanol intercalated Kaol were investigated. Partial methanol molecules entered the interlayers of Kaol to form some intermediate structures with the same d-spacing as that of DMSO intercalated Kaol. Different numbers of grafted methoxy and water molecules coexist together in the interlayer to form the final structures of methanol intercalated kaolinite (MeOm/nH2O/Kaol). The whole intercalation process is energy-consuming, and the presence of DMSO would affect the intercalation of methanol. Meanwhile, the formation energy from intermediate structures to final structures was found reduced under the participation of water.

Effects of nanoclay modification with aminopropyltriethoxysilane (APTES) on the performance of urea–formaldehyde resin adhesives

Urea-formaldehyde (UF) resins, as the most common adhesives for wood-based composites, emit formaldehyde, which is forcing producers to find a solution to this problem. Using scavengers is a practical way of reducing formaldehyde emissions, but sometimes these materials change the properties of the adhesive. This study investigated the effect of adding nanoclay and nanoclay modified with aminopropyltriethoxysilane (APTES), as scavengers, on the formaldehyde emission and the properties of the urea-formaldehyde resin. Modification of nanoclay with APTES was confirmed by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis. After the addition of nanoclay and modified nanoclay to the urea-formaldehyde resin, the emission of formaldehyde decreased by 22% and 61%, and the physical and mechanical properties were improved. The FTIR, XRD, and differential scanning calorimetry results showed that the addition of nanoclay and modified nanoclay improved the characteristics of the adhesive, reduced the crystalline areas, and delayed the curing of the adhesive. Additionally, according to thermogravimetric analysis results, addition of nanoclay and modified nanoclay increased the thermal stability and reduced the weight loss of urea formaldehyde resin.

Impact of Nanoclays on Chemical Fractions and Mechanical Performance of Asphalt Binders

Asphalt binder often is modified to obtain better performance of the pavement. Some recent studies have considered nanoclay as an alternative to currently practiced styrene-butadiene-styrene (SBS) modification to reduce the asphalt binder’s overall cost. This study evaluated any notable changes in the chemical composition of the binder due to the nanoclay modification and investigated any correlation between the chemical composition and mechanistic properties of the asphalt binder. It was found that changes in the chemical composition of nanoclay-modified binders are crude source–dependent. After nanoclay modification, the binders that originated from the Arabian crude were found to be more acidic than the binders from the Canadian crude source. However, nanoclays did not have any notable impact on the polarity of the tested asphalt binders regardless of their crude sources. The saturates, aromatics, resins, and asphaltenes (SARA) analysis results of asphalt binders revealed that the n-heptane insoluble contents increased notably after modification with nanoclays, whereas the saturates content decreased due to aging. Some mechanical properties (e.g., viscosity and rutting factor) were found to be correlated with n-heptane insoluble contents. Moreover, the sessile drop analysis test result showed that the nanoclay-modified binders offered superior bonding with gravel than with sandstone. Multiple linear regression analyses suggest that there is a fair (R2=0.55) correlation between the binders’ SARA components and compatibility for gravel.

Modification of bentonite nanoclay for textile application

The influence of the bentonite content (1, 3, 5 wt%) on the mechanical properties of lightweightcotton (C), polyester (P) and polyester-cotton (P/C 50/50) fabrics was investigated. Starch was used asa water-insoluble binder for coating fabrics. Bentonite nanoparticles were obtained by repeated hydration,decantation and evaporation of the water dispersion. The bentonite particle size was determinedby the XRD method using the Debye-Scherrer equation. The diffraction of the laser beam was used todetermine particles size distribution. The addition of bentonite nanoclay significantly improved tensilestrength (26-61% and 99–118% in the warp and weft direction, respectively) and tear strength (4‒13%and 5–24% in the wrap and weft direction, respectively) of coated fabrics. Their abrasion resistancehas also slightly increased. The biggest changes were noted for the cotton fabric, the smallest for thepolyester fabric, which may result from the low compatibility between starch and the polyester fabric.

Investigations on corrosion inhibition performance of self-healing nano-clay modified epoxy coatings

Motivated by the need to mitigate corrosion and improve the lifespan of concrete structures, we report in this paper the results of our experimental investigation using hybrid nano-modified epoxy coatings for mild steel bars in concrete using a combination of nano-clay and self-healing tung-oil microcapsules. The prepared nano-modified coatings were characterized by Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). They were applied on plain mild steel bars and subjected to accelerated impressed current corrosion. Their performance was assessed by non-destructive electrochemical corrosion current and ultrasonic guided wave measurements. These assessments were corroborated by visual inspection and destructive testing parameters of residual mass loss and tensile strength. Coated rebars were also subjected to simulated damage to investigate the self-healing capabilities of the prepared coatings. Both non-destructive and destructive results demonstrate that hybrid nano-modified coatings utilizing nano-clay (2 wt% of epoxy resin) with self-healing tung-oil microcapsules (10 wt% of epoxy matrix) are effective in inhibiting initiation as well as progression of corrosion made possible by a dual-protection mechanism. Initiation of corrosion was delayed effectively due to the paths of diffusing aggressive ions made tortuous by nano-clay modification. In addition, the progression of corrosion was arrested by self-healing tung-oil microcapsules. We believe these results could provide an important tool in reaching the goal of sustainable construction.

Epoxy chain extender grafted pyrophyllite/poly(ethylene terephthalate) composites with enhanced crystallinity and mechanical properties

AbstractThe surface‐grafting modification of nano clay has become increasingly important for improving the practical application of clays. In this study, an epoxy chain extender ADR‐4468 was used to modify the surface of pyrophyllite (Prl), and the effect of ADR‐4468‐modified pyrophyllite (A‐Prl) on the properties of poly(ethylene terephthalate) (PET) and PET/poly(ethylene glycol‐co‐1,3/1,4‐cyclohexanedimethanol terephthalate) (PETG) composites was investigated. The modified composites were characterized by Fourier transformed infrared spectroscopy, X‐ray diffraction and TG, which proved that the A‐Prl was successfully synthesized, and the addition of ADR‐4468 did not change the crystal structure of pyrophyllite. The grafted ADR‐4468 improved the agglomeration of Prl, and some A‐Prl reached nano‐scale dispersion in PET and PET/PETG composites. The rheological properties, crystallization behavior and mechanical properties of PET and PET/PETG nanocomposites were systematically investigated. The results showed that A‐Prl was an effective nucleating agent for PET, which significantly improved the crystallization properties of PET composites. The A‐Prl also improved the comprehensive mechanical properties of PET and PET/PETG nanocomposites. In particular, the impact toughness of A‐Prl/PET/PETG composite with 1.5 wt % A‐Prl was increased by 120% compared with that of pure PET. The functional additive is expected to be used in the preparation of high‐performance and recyclable PET composites.

Novel epoxy‐based glass fiber reinforced composites containing compatibilized para‐aramid fibers and silanized nanoclay for improved impact strength

AbstractThis research developed epoxy‐based glass fiber reinforced composite (GFRPs) containing multi‐scale fiber reinforcement comprising of silanized nanoclay (nano‐reinforcement) and compatibilized para‐aramid (PA) fibers (micro‐reinforcement) for enhanced impact strength and tensile‐flexural properties. VARIM technique was used for fabrication of GFRPs. Surface modification (silanization) of nanoclay was confirmed by FTIR and that of PA fibers was confirmed by SEM‐EDS and FTIR. Dispersion/morphology of nanoclay in the processed nanocomposites was determined by XRD and TEM analysis. Three different methods were used for the compatibilization of PA fibers. All methods exhibited a substantial increase in impact strength without a decrease in flexural/tensile strength. Nanocomposite containing 1.0 phr MAH treated PA fibers and 2 phr silanized nanoclay showed the highest improvement in impact strength (34% higher than the reference composite) along with minor improvements in tensile strength (6%), and flexural modulus (13%). SEM micrographs of the fractured surface of impact test samples were used to identify the mechanisms/reasons for the improved mechanical performance of the newly developed GFRPs.

Modification of nanoclay with different methods and its application in urea-formaldehyde bonded plywood panels

ABSTRACT The reinforcement of pristine nanoclay (PNC) and modified nanoclay (MNC) in urea-formaldehyde (UF) resins at the alkaline stage of synthesis was investigated in this work. The modification of PNC using copper (II) chloride (CuCl2) as transition metal ions was carried by three different modification methods that were coded as Cu-MNC (25, 36), Cu-MNC (60, 6), and Cu-MNC (80, 3), respectively. The modification of PNC was characterized by X-ray diffraction, showing the increased d-spacing after the modification. The reinforcement of 5 wt% of PNC and Cu-MNC at the alkaline reaction of UF resins that were coded as UF/PNC, UF/MNC (25, 36), UF/MNC (60, 6), and UF/MNC (80, 3). The X-ray diffraction study showed that the addition of PNC and Cu-MNC into the UF resins decreased the crystallinity of resins from 48.1% to 45% for UF/PNC and 25% for all UF/MNC. The curing behavior exhibited that the activation energy of UF resins decreased with addition of PNC and Cu-MNC. The loading of PNC and Cu-MNC into UF resins improved the adhesion and reduced the formaldehyde emission of UF resins in plywood. Statistical analysis suggested that UF/MNC (80, 3) produced plywood with greater adhesion strength and lower formaldehyde emission over other modified resins.

Modification of Oxidized Starch Polymer with Nanoclay for Enhanced Adhesion and Free Formaldehyde Emission of Plywood

This study is aiming of developing eco-friendly wood adhesive based on oxidized starch (OS) modified by nanoclay to enhance their adhesion and no formaldehyde emission. Two types of nanoclay such as pristine-bentonite (P-BNT) and transition metal ion modified-pristine-bentonite (TMI-P-BNT) at three levels (i.e., 1, 3, and 5%) were used for the modification of OS adhesive. Basic properties, chemical properties and thermal properties of the modified OS adhesives were examined with various analysis techniques to understand the influence of nanoclay modification on OS polymer. As the nanoclay level increased, the modified OS adhesives had greater solids content and viscosity but the gelation time decreased, indicating a faster curing of the modified OS adhesive. X-Ray diffraction of the modified OS adhesives resulted in a decrease in the 2θ value and enlarged d-spacing value, showing that the nanoclay had been intercalated within OS polymer molecules. Two peaks at 526 cm−1 and 461 cm−1 detected by FTIR were assigned to Si–O–Al and Si–O–Si vibrations, respectively, and confirmed the presence of nanoclay in the OS polymer. Thermogravimetric analysis showed that the added nanoclay improved thermal stability of OS adhesives. The modified OS adhesives with 5% TMI-P-BNT enhanced their adhesion strength from 0.9 to 1.25 MPa, and resulted in free formaldehyde emission (near to 0.01 mg/L) from plywood panel. These results indicated that the modification of OS adhesives with 5% TMI-P-BNT could be used as bio-based and environmentally friendly plywood adhesive with zero formaldehyde emission.

Different model approaches with residual errors to predict the short and long-terms fluid loss and rheological properties of clay bentonite modified with nano-montmorillonite

ABSTRACT In this study, the percentage of bentonite in the WBM was ranged from 2%-8% as a percentage of the weight of water. The percentage of clay Nanopowder Montmorillonite (NC) was ranged between 0% and 1% by mass of drilling mud. The tests were performed under various temperature conditions ranged between 25°C and 85°C. From the lab studies and numerical examinations, the electrical resistivity (ER) was identified as a sensing property of the WBM so that the rheological properties can be estimated during the construction. The additional 1% NC reduced the ER of the WBM by 15% to 36% depending on the composition of the drilling fluid and the temperature of testing. The nanoclay modification increased the yield stress (yield point) and shear stress limit tolerance of the WBMs measured using the Vipulanandan rheological model by 32% to 60%, and the outcome of the model prediction was related with Vocadlo model. The laboratory HPHT fluid loss tests were conducted on the drilling fluids based bentonite modified with NC using API standard test up to 420 minutes until the end of the fluid loss. Zero fluid loss was obtained when 8% of bentonite drilling mud modified with 1% of NC at 25°C. The Vipulanandan fluid loss model predicted the short- and long-term fluid loss and the upper limit of fluid losses very well.

Improvement on Fatigue Performance of 3-D Orthogonal Woven Composite with Nanoclay Modification

3-D orthogonal woven composite (3DOWC) has attracted great interest in the industrial and energy fields, due to their excellent mechanical properties. However, due to the poor bonding strength between fiber and epoxy, it’s mechanical properties, especially the fatigue behavior are critical for structural design in the practical applications. The nanoclay modification composite reinforced with 3-D orthogonal woven fabric (3DOWF)/epoxy resin was fabricated using resin infusion under flexible tooling (RIFT). The quasi-static tensile and fatigue behavior of 3-D orthogonal woven composite (3DOWC) in 0 ° and 90 ° inclined to warp direction were evaluated and compared to the pristine one or composite material not modified with nanoclay. The fatigue behavior such as the S-N curves, stress-strain curves, stiffness degradation curves and residual strength were also obtained. The results show that the tensile strength, modulus and the fatigue life were improved effectively due to nanoclay modification. However, the stiffness degradation of nanoclay addition in 90 ° direction was decreased.

Evaluating the Suitability of Nanoclay-Modified Asphalt Binders from 10°C to 70°C

This study presents the results of laboratory experiments and analyses carried out to evaluate the rheological performance of nanoclay (NC) modified asphalt binders from 10°C to 70°C. A viscosity graded binder, VG-30, was modified using 2%, 4%, and 6% NC by weight of the base binder. The suitability of the NC modification was ascertained using a series of rheological evaluations, including a frequency sweep test (10°C–70°C), linear amplitude sweep (LAS) test (10°C, 20°C, and 30°C), and multiple stress creep and recovery (MSCR) test (40°C, 50°C, 60°C, and 70°C). Scanning electron microscopy (SEM) was carried out on the unmodified and modified asphalt binders to assess the microscopic dispersion of NC in the base asphalt binder. The SEM images demonstrated that with an increase in the percentage of NC, the physical dispersion of the modifier in the base asphalt binder changes. Six percent of the NC was found to form an interlocked phase within the composite asphalt binder matrix. It was found that the h-parameter obtained from Cole-Cole plots at individual temperatures offers a better and clearer comparison between the asphalt binders in comparison to the master curves and combined Cole-Cole plots. The analysis using h-parameter indicated a higher elasticity and lower temperature susceptibility offered by the NC modified binders. With an increase in the percentage of nanoclay, both the fatigue and rutting performance improved. The value of the Jnr decreased while the value of the percentage recovery (R) increased with an increase in the percentage of the NC. At the temperature of 70°C, only a 6% NC modified asphalt binder was found to be suitable for standard traffic conditions. The LAS test resulted in a higher value of A and an insignificant increase in the value of B for NC modified binders in comparison to the values obtained for VG-30. No specific trend was observed in the value of A at different CSRs, and it suggested from this study that an average value may be used. The number of cycles to failure for NC modified binders was found to be higher than VG-30. A statistical analysis carried out for different parameters revealed that the NC modification has a significant effect on the performance parameters of asphalt binders at all the test temperatures. A simple framework for the cost-benefit analysis has been proposed in this study, which revealed a 6% NC modification to be the optimum dosage for attaining a higher benefit in comparison to the cost.

Zero fluid loss, sensitivity and rheological properties of clay bentonite (WBM) modified with nanoclay quantified using Vipulanandan models

To improve the performance, sensibility, rheological properties, fluid loss of the bentonite water-based drilling mud (WBM), and minimizing the fluid loss of the WBM. The impact of bentonite modified with nanoclay (NC) on the sensibility, rheological properties, and fluid loss of the WBM was investigated. Depend on the information collected from different research studies, the percentage of bentonite in the WBM was ranged from 2%-8% as a percentage of the weight of water. The percentage of NC was ranged between 0 and 1% by mass of drilling mud. The tests were performed under various temperature conditions ranged between 25 °C and 85 °C. From the lab studies and numerical examinations, the electrical resistivity (ER) was identified as a sensing property of the WBM so that the rheological properties can be estimated during the construction. The additional 1% NC reduced the ER of the WBM by 15% to 36% depending on the composition of the drilling fluid and the temperature of testing. The nanoclay modification increased the yield stress (yield point) and shear stress limit tolerance of the WBMs measured using Vipulanandan rheological model by 32% to 60%, and the outcome of the model prediction was related with Vocadlo model. The laboratory HPHT fluid loss tests were conducted on the drilling fluids based bentonite modified with NC using an American Petroleum Institute (API) standard test up to 420 min until the end of the fluid loss. Zero fluid loss was obtained when 8% of bentonite drilling mud modified with 1% of NC at 25 °C. The Vipulanandan fluid loss model predicted the short and long-term fluid loss and the upper limit of fluid losses very well.

Effects of nanoclay modification with transition metal ion on the performance of urea–formaldehyde resin adhesives

As a way of reducing the formaldehyde emission and improving the adhesion of urea–formaldehyde (UF) resins, this study investigated the addition effects of pristine nanoclay (PNC) or modified nanoclay (MNC) with transition metal ion (TMI) on the performance of UF resin adhesives. Instead of a conventional simple mixing (SM) of MNC with UF resin (coded as MNC-SM), this study explored adding PNC or MNC into either the alkaline (ALK) or acidic (ACD) reaction during the synthesis of UF resins, which were coded as PNC-ALK, PNC-ACD, MNC-ALK, and MNC-ACD, respectively. For the first time, we report that the MNC-ALK resins result in almost amorphous UF resins with 25% crystallinity, which consequently increases the cross-linking, and improve the adhesion strength and decrease formaldehyde emission of modified UF resins. It is believed that the intercalated or exfoliated MNCs facilitate the formation of more cross-linking in the modified UF resins, leading to a better cohesive strength.

Effect of green modification of nanoclay on the adhesion behavior of EPDM rubber to polyester fabric

Rubber-coated fabrics have received much attention because of their excellent processability and unique mechanical properties. In this research, two approaches were used to prepare organoclay/ethylene propylene diene terpolymer (OC/EPDM) nanocomposites. One of them was based upon a nonpolar EPDM in which the EPDM was grafted with maleic anhydride (EPg) with OC namely (OC/EPg/EPDM); while the other was based on a green modified organoclay in which stearic acid was used to form an expanded organoclay (EOC) namely (EPDM/EOC). The EPDM compounds were loaded with 20 wt% of a long oil alkyd resin based on soyabean oil (LAR). The bonding system applied in the mixes consisted of hexamethylenetetramine-resorcinol-hydrated silica (HRH). The different mixes were loaded with different concentrations of OC and EOC. The rubber nanocomposites were immersed in an equal weight of toluene to prepare a rubber dough. This dough was spread over a polyester fabric; cured to form the final proofed product. The peel strength technique was used to assess the adhesion strength between the EPDM rubber and the polyester fabric. The reaction mechanism of EOC with the EPDM/polyester fabric in the presence of a bio-alkyd resin was studied. Moreover, the rubber proofed fabric was subjected to ultraviolet (UV) irradiation at different doses. The net product of proofed fabric was also subjected to various tests such as air and water permeability, flammability and antimicrobial activity. In all cases, the use of the EOC/EPDM or the OC/EPg/EPDM systems enhanced the physico-mechanical and physico-chemical properties of the rubber-proofed fabrics with the exception of thermal stability as determined from themogravimetric analysis which decreased, especially the degradation onset temperature (T10%). These materials provide a promising approach for use in advanced rubber technology applications.

Wear Behavior of Short Glass Fiber Reinforced Polymer Composite with Nanoclay Modification

This study is aimed to evaluate the effect of nanoclay incorporation on wear properties of short glass fiber reinforced polymer (GFRP) composite. Three different nanoclay contents of 1.0, 3.0 and 5.0wt% were dispersed into epoxy resin using a three-roll mill machine. The fibers were dispersed using mechanical mixer machine. Dry sliding and abrasive wear tests were conducted using pin-on-disc and abrasive resistance tribometer, respectively. The tests were conducted under 30N load and at 300rpm speed for 10000m sliding distance. The addition of nanoclay filler in epoxy polymer has shown improvement towards wear properties of GFRP composite, of up to 65% and 45% under dry sliding and abrasive wear resistance, respectively. The nanoclay appears to improve the microstructural strength leading to better load carrying capacity of the composite, advancing its effect as secondary reinforcement to the polymer composite.

Mechanical Properties Improvement of Nanoclay Addition Epoxy 3D Orthogonal Woven Composite Material

In this study, the influence of nanoclay on mechanical properties of epoxy/3D orthogonal glass fiber woven composite was studied. The DK2 polymer-grade organic nanoclay modification composite specimen reinforced with 3D orthogonal woven fabric/epoxy was manufactured by means of Resin Infusion under Flexible Tooling (RIFT) process. Firstly, the modification mechanism with nanoclay was characterized by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscope (TEM). Secondly, as far as the tensile behavior between the fiber/matrix of the composite was concerned, the modification process was optimized by means of nonlinear least square fitting. The results show that the bonding strength between the fiber and matrix was improved and the delamination and debonding between fiber and matrix was retarded and shifted to cohesive failure of the matrix due to the nanoclay modification with respect to results from FT-IR, XRD and TEM. The tensile strength and modulus of composite were increased by 23.32 % and 16.42 % respectively due to 3 of nanoclay addition. The contact angle also shows that the dispersion effect and wettability at this state. The tensile stress-strain curve was fitted by applying nonlinear fitting. It can be concluded that there has a good modification effect with 3 wt% of nanoclay addition.