Coconut Sheath Research Articles

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

Effect of montmorillonite nanoclay on temperature dependence mechanical properties of naturally woven coconut sheath/polyester composite

The untreated, NaOH and silane-treated naturally woven coconut sheath/polyester composites have been developed using compression molding technique by varying the weight percentage (1, 2, 3, and 5 wt%) of organically modified montmorillonite (MMT) nanoclay to find the mechanical properties as a function of temperature. X-ray diffraction, scanning electron microscope and transmission electron microscope have been performed to understand the distribution of nanoclay mechanism and morphological structure of treated coconut sheath fiber. Dynamic mechanical analysis revealed a decrease in storage modulus ( E′) with the increase in temperature by a considerable fall in the temperature range of 50℃ to 110℃. The loss modulus ( E″) and damping peaks (tan δ) were found to be higher after the chemical treatment of coconut sheath. The maximum increase in E′ and E″ values were found in the case of silane-treated composites. In all types of composites, the dynamic factors were observed to increase with the incorporation of nanoclay but the anomalous trend was noticed according to the wt%. A slight increase in shift of glass transition temperature value was noticed in association with the E″ peaks for silane and NaOH-treated composites compared to untreated composites.

Dynamic mechanical analysis and free vibration behavior in chemical modifications of coconut sheath/nano-clay reinforced hybrid polyester composite

Naturally woven coconut sheath, a new natural fiber available in the form of woven mat is used as fiber reinforcement in polyester matrix. The hybridization effect of montmorillonite (MMT) on naturally woven coconut sheath/polyester composite has been investigated experimentally for free vibration characteristics using impulse excitation technique (IET). In the present study, naturally woven coconut sheath/clay-reinforced hybrid polyester composites were fabricated using a compression molding machine. The effect of organoclay addition (1, 2, 3 and 5 wt%), alkali (ATC) and silane treatment (STC) of the coconut sheath surface on free vibration characteristics were analyzed. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques were used to characterize the morphology of coconut sheath and structure of clay dispersed polyester. The dynamic mechanical analysis (DMA) and Fourier transform infrared (FTIR) analysis were carried out to analyze the effect of surface topology on chemically treated coconut sheath. The mechanism of chemical modifications on natural frequencies and the resultant improvement in the temperature dependence mechanical properties have also been reported. Enhanced vibration properties are observed up to 3 wt% of clay dispersion in hybrid composites, then it gets reduced for higher clay (>3 wt%) content. Modal damping of the hybrid composite is influenced by the addition of nanoclay and the surface treatments of the coconut sheath. Experimentally obtained natural frequencies are in good agreement with analytical and numerical results.

Mechanical and free vibration properties of montmorillonite clay dispersed with naturally woven coconut sheath composite

In this investigation, naturally woven coconut sheath is used as a new type of reinforcement. The hybrid composites are developed with the combination of naturally woven coconut sheath/E-glass/nanoclay using unsaturated polyester matrix and the effect of nanoclay on the mechanical and free vibration behavior is studied. It is found that the addition of nanoclay improved the mechanical and damping properties of the composite owing to the improved stiffness of the matrix by better dispersion of clay. In addition, the effect of alkali and silane treatments on fibers and different stacking sequence were investigated. It was observed that the alkali treatment of fibers improved the mechanical properties of the composites when cellulose fiber was present. This investigation presented a peculiar result in the case of silane treatment with the nanoclay, which is in contradiction with the earlier works. The stacking sequence of coconut sheath/coconut sheath/glass with alkali treatment of fibers provides the optimum increase in mechanical strength and free vibration characteristics. X-ray diffraction and transmission electron microscope were performed to understand the dispersion of nanoclay and its strengthening mechanism. In addition, scanning electron microscopy was used for fractography analysis. This investigation suggests an alternative material for the field of composites.

Investigation on mechanical and tribological behavior of naturally woven coconut sheath‐reinforced polymer composites

AbstractThe article presents the results of experimental investigation on mechanical and dry sliding wear behavior of unsaturated polyester resin (USP), reinforced with naturally woven coconut sheath and glass fibers. The mechanical properties of coconut sheath (N) and glass fiber (G) reinforced polyester composites were studied, and the tribological behaviors were tested on pin‐on‐disc sliding wear tester. Mass loss was determined as a function of sliding distance for a sliding velocity of 3.5 m/s and an applied normal load of 40 N. The experimental result revealed that the mechanical properties and wear resistance of the composites depend on the wt% reinforcement of coconut sheath/glass fiber and sliding distance. The hybrid reinforcement (GGN) greatly increased the mechanical properties of USP. At lower sliding distance, the N‐reinforced USP had lower wear loss, whereas at higher sliding distance, the hybrid fiber‐reinforced (GGN) USP composite had lower wear loss. Furthermore, the work showed that the higher sliding distance bring about changes in the worn surface features such as interface separation, inclined fracture of fibers, loss of matrix, and the appearance of debris with the two different fibers. The worn surfaces were also examined by scanning electron microscopy. The study showed differing trends with load for the two types of reinforcements. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Fractography Analysis of Naturally Woven Coconut Sheath Reinforced Polyester Composite: A Novel Reinforcement

In this work, naturally woven coconut sheath, a new type of reinforcement was used. Composite Laminates were prepared in a compression molding press. Tensile, flexural and impact tests were conducted as per ASTM standards, and results were compared with the glass fibre composite. Fractured specimens were analyzed with the help of scanning electron microscope images. Enhancements in mechanical properties were found with the new reinforcement. And the coconut sheath was found to be a suitable material that can reduce the utilization of non-decomposed glass fibres for polymer composite reinforcements.

Studies on the Influence of Silane Treatment on Mechanical Properties of Coconut Sheath-Reinforced Polyester Composite

In this investigation, naturally woven coconut sheath, a new type of reinforcement was used. The composite was fabricated using compression molding machine. The mechanical properties like tensile, flexural and impact strengths were studied according to the ASTM standards. For comparison, conventionally used glass fiber-reinforced composites were also fabricated and tested. In all the testing, the coconut sheath-reinforced polyester composite showed enhanced results. For further improvement in the properties, chemical modification such as silane treatment was given to the fibers. As expected, the mechanical properties of coconut sheath-reinforced composites were improved.