Investigation of Weight Fraction and Alkaline Treatment on Catechu Linnaeus/Hibiscus cannabinus/Sansevieria Ehrenbergii Plant Fibers-Reinforced Epoxy Hybrid Composites

The aim of the present work is to develop novel hybrid composites using areca, kenaf, and snake grass fibers as reinforcement and epoxy as the matrix. The areca, kenaf, and snake grass fibers were extracted from Catechu Linnaeus, Hibiscus cannabinus, and Sansevieria Ehrenbergii plants, respectively, and treated with 5% NaOH to improve the interfacial adhesion between the hydrophilic fiber and the hydrophobic matrix. Hybrid composites were developed by the compression molding technique and formulated based on the weight fraction of fibers. Tensile, flexural, and impact strength and hardness samples were prepared as per ASTM D 3039, ASTM D 790, ASTM D 256, and ASTM D 2240, respectively. The effects of alkaline treatment on developed hybrid composites were investigated. The developed hybrid composites with 20% wt. snake grass and 10% wt. areca fiber present interesting mechanical properties with a tensile strength of 58 MPa, flexural strength of 124 MPa, impact strength of 5.24 kJ/m2, and hardness of 88. The results indicate that maximum mechanical properties were obtained for alkaline-treated fiber composites with 20% wt. snake grass fiber compared to untreated fiber composites owing to better adhesion between the treated fiber and the matrix. The effect of alkaline treatment was analyzed by Fourier transform infrared. The fractured surfaces of tested samples were analyzed by scanning electron microscopy.

Tensile Characterizations of Oil Palm Empty Fruit Bunch (OPEFB) Fibres Reinforced Composites in Various Epoxy/Fibre Fractions

Oil palm empty fruit bunch (OPEFB) single fibers and reinforced composites were comprehensively characterized through tensile tests to assess their performance as potential reinforcing materials in polymer composites. The performances of OPEFB single fibers and reinforced composites with untreated and treated fibers conditions were compared. The fibers were variously treated with 3% sodium hydroxide, 2% silane, 3% sodium hydroxide mixed with 2% silane, and 3% sodium hydroxide prior to 2% silane for 2 hours soaking time. The highest toughness of the single fibers test was then selected to proceed with composites fabrication. The OPEFB composites were fabricated in 90:10, 80:20, 70:30, and 60:40 epoxy-fibre fractions. The result shows that the selected treated fiber composite exhibits better performance. The selected treated fiber composite increased the highest ultimate tensile strength by 145.3% for the 90:10 fraction. The highest Young’s Modulus was increased by about 166.7% for 70:30 fraction. Next, the highest toughness was increased by 389.5% for the 30:70 fraction. The treated fibers provided a better interlocking mechanism between the matrix and fibers in reinforced composites, thus improving their interfacial bonding.

Enhancing Anti-Static Performance of Fibers by Construction of the Hybrid Conductive Network Structure on the Fiber Surface

The hybrid antistatic agent SCNTs/OAA composed of sulfonated carbon nanotubes (SCNTs) and organic antistatic agent (OAA) was treated on the fiber surface to construct the hybrid conductive layer. Among them, SCNTs were synthesized through a simple method, and their chemical structure and morphology were characterized. SCNTs had good dispersibility due to the presence of sulfonic acid groups, which made SCNTs uniformly dispersed on the fiber surface. The SCNTs/OAA-treated fiber was hardly affected by relative humidity, because SCNTs form a continuous and uniform physical conductive network on the fiber surface. When the addition amount of SCNTs/OAA was 0.5~2 wt%, the fiber had excellent antistatic ability. Under the synergistic effect of SCNTs and OAA, the resistivity of SCNTs/OAA-treated fiber was almost not affected by fiber stretching.

Effect of Wood Fiber Surface Treatment on the Properties of Recycled HDPE/Maple Fiber Composites

This work reports on the production and characterization of recycled high density polyethylene (R-HDPE) composites reinforced with maple fibers. The composites were produced by a simple dry-blending technique followed by compression molding. Furthermore, a fiber surface treatment was performed using a coupling agent (maleated polyethylene, MAPE) in solution. FTIR, TGA/DTG, and density analyses were performed to confirm any changes in the functional groups on the fiber surface, which was confirmed by SEM-EDS. As expected, the composites based on treated fiber (TC) showed improved properties compared to composites based on untreated fiber (UC). In particular, MAPE was shown to substantially improve the polymer–fiber interface quality, thus leading to better mechanical properties in terms of tensile modulus (23%), flexural modulus (54%), tensile strength (26%), and flexural strength (46%) as compared to the neat matrix. The impact resistance also increased by up to 87% for TC as compared to UC. In addition, the maximum fiber content to produce good parts increased from 15 to 75 wt% when treated fiber was used. These composites can be seen as sustainable materials and possible alternatives for the development of low-cost building/construction/furniture applications.

Effect of Surface Treatment of Polypropylene (PP) Fiber on the Sulfate Corrosion Resistance of Cement Mortar

Sulfate erosion is one of the most complex and harmful chemical corrosion actions. Following sulfate erosion, concrete expands, cracks, dissolves, peels off, and decreases in strength, which affects the durability of structures. Polypropylene fiber (PP) is widely used in various concrete structures because of its good mechanical properties and chemical corrosion resistance. However, PP fiber has a number of shortcomings, such as a smooth surface, poor hydrophilicity, lack of active groups in the molecular chain, and agglomeration and poor dispersion in cement-based materials. These issues limit its application in cement-based materials. Although the use of a silane coupling agent to modify the surface of PP fiber is effective, the influence of treated PP fiber on the sulfate resistance of cement-based materials is not significant. In this study, a PP fiber treated with a silane coupling agent was used to examine effects of different cement-to-sand ratios (C/S) and dosages of the treated PP fiber on the sulfate erosion resistance of cement mortar. Furthermore, the apparent morphology, mass loss rate, flexural strength, corrosion resistance coefficient, and microstructure of the concrete were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the PP fiber became rough after modification. Active groups were introduced on the fiber surface, which were well dispersed in the mortar and formed a good network distribution structure in the cement mortar, thereby slowing the erosion rate of the PP fiber mortar in a sodium sulfate solution. At a C/S ratio of 1:1 and a treated fiber dosage of 0.6%, the treated fiber mortar has exhibited good sulfate resistance. In addition, the monofilament fiber immersion test revealed that a layer of sodium sulfate crystals was deposited on the fiber surface, thereby increasing the roughness of the fiber surface and the pull-out force of the fiber from the cement matrix, this result indicated that the interfacial adhesion between the treated PP fiber and cement matrix was improved, which in turn led to the improvement in the sulfate erosion resistance of the treated PP fiber.

Comparison of various methods of flines of flax raw materials used in Kazakhstan

Significant attention in the article is devoted to the study of different technology of the lobe and the physical and mechanical properties of oil flax fiber and primary processing in relation to Kazakhstan. When studying the technology of oil flax fiber soaking, the task was set of separate the fiber from the stems, removal of lignin and pectin-forming substances. The questions of various technologies of the flax stalks are considered. The most optimal technology for producing textile fiber was determined for the conditions of Kazakhstan. Comparative studies of linear density and length of fibers have been carried out. According to the results obtained, the linear density of the fiber in an aqueous medium is 6.7 T, the result of the treated fiber is 3.1 T. That is, the technology used is to remove lignin and pectin from the fiber.

The Effects of Different Chemical Treatment Methods and Maleic Anhydride Grafted Polyethylene on the Mechanical and Thermal Properties of Alpinia galanga Fiber Reinforced Polyethylene Composites

In this study, the effect of different treatments and the addition of maleic anhydride grafted polyethylene (MAPE) on the mechanical and thermal properties of Alpinia galanga (AG) fiber/high-density polyethylene (HDPE) composites were investigated. The AG fibers were pretreated with sodium hydroxide (NaOH) and then treated with 3-aminopropyltriethoxysilane (3-APE) as well as treated with p-toluenesulfonic acid (PTSA). The samples were first prepared by melt blending method before being injected to specimen dumbbell shape using an injection moulding machine. Three different fiber loadings were studied, such as 3, 6, 10 and 15 wt%. The tensile test results revealed that the NaOH and 3-APE treatments increased the tensile strength of AG/HDPE composites with the addition of MAPE at all fiber loadings, whereas tensile strength of PTSA treatment improved at 3 wt% fiber loading. The morphological studies confirmed a better adhesion between treated fiber and HDPE matrix with the inclusion of MAPE. Thermal analysis study showed that NaOH, 3-APE and PTSA treatments on AG fibers improved the thermal stability of the composites with an addition of MAPE by delaying the thermal degradation of the composites. The water absorption test proved NaOH and 3-APE treated fiber exhibited lower water absorption than other composites with the inclusion of MAPE. Overall, the results indicated that chemical treatment with NaOH and 3-APE with the presence of MAPE is a good approach towards the development of natural fiber composites.

Characterization of Microcrystalline Cellulose Isolated from Conocarpus Fiber

Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.

Effect of Sisal Fiber-Snail Shell Hybrid Reinforcement on some Mechanical Properties and Moisture Uptake of Unsaturated Polyester Resin Based Composites

This study investigates the hybrid effect of chemically modified sisal fiber and snail shell particles on the performance of polyester composites. The sisal fiber used was extracted by soil retting method and some portions were treated with potassium hydroxide (KOH) and sodium hydroxide (NaOH) solutions, respectively. The snail shell was calcined before grinding and sieving into particle size of ˂75 μm. The composites were developed using randomly dispersed open mould technique by varying the reinforcements between 2-10 wt. %. The particulate snail shell was analyzed with XRF where it was discovered that Mn and Ni were the major constituents while the developed composites were also subjected to different tests in accordance with the existing ASTM standards. The results revealed that the incorporation of sisal fiber and snail shell particles in the polyester matrix resulted in better tensile and flexural properties. The performance of the materials in moisture environment showed that chemically modified sisal fiber samples reduce the tendency for moisture absorption. The influence of the modification was best for samples from KOH treated fiber compared to NaOH treated fiber. Hence, it was discovered that snail shell/modified sisal fiber aid the enhancement of the performance of the developed composites.

The Effect of Alkalization Treatment on Fiber-Matrix Compatibility in Natural Fiber Reinforced Composite

This work was aimed to investigate the effect of alkalization treatment on the fiber-matrix interfacial interaction and hence their compatibility. Kenaf fiber was treated using a 6% NaOH solution for 8 hours. The composites were produced by mixing the treated fiber with PP at various temperatures, duration, and fiber composition. Alteration on the surface chemistry of the fiber was identified by performing FTIR analysis. The surface energy of the treated fiber was mathematically derived from the contact angle measurement results. The compatibility level between treated fiber and PP matrix was visualized through FESEM analysis. Tensile strength tests were also conducted to obtain data necessary for exploring the relationship between the thermodynamic aspects of the fiber-matrix interfacial interaction and the mechanical properties of the composites. The FTIR spectra show that there was significant increase in the %transmittance at wavelength range of 3100-3600 cm-1 indicating that O-H groups were degraded during treatment. However, the polar component of the surface energy for treated fiber was instead higher compared to the untreated one. The SEM images show that there are no noticeable reduction in the size of the treated fibers as expected. On the other hand, the tensile strength of the PP-treated fibers composites reached its highest value when the matrix were loaded with fibers at the lowest percentage i.e. 5%.