Effect Of Alkaline Treatment Research Articles

Characterisation of Miswak (Salvadora persica) Fibre-reinforced Polylactic Acid Composites Prepared by Twin Screw Extrusion

Processing of polymer composites employing fibres from sustainable sources as reinforcement has drastically grown in recent years. This research used Miswak fibres (MF) and polylactic acid (PLA) as the main materials for composite processing. Natural fibres typically include a hydroxyl group (-OH), which makes them hydrophilic. In contrast, the hydrophobic nature of polymer matrices causes them to naturally repel water. This problem was resolved by chemically altering the surface of natural fibres using a 2 wt% sodium hydroxide (NaOH) solution. In this paper, the effect of alkaline treatment has been proven by performing chemical analysis, tensile properties, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to analyse the influence of treated MF content on composite characteristics. The results revealed that biocomposites with modified miswak fibres exhibited better properties than untreated miswak fibres-reinforced polymer biocomposites. Treated MF/PLA composites showed an increase in tensile strength of 52.9% and tensile modulus of 8.16%. From the chemical composition test, lignin composition was reduced from 5.09% to 3.06% and hemicellulose from 28.12 to 10.62% after MF was treated. Meanwhile, thermal properties for both TGA and DSC revealed the elimination of hemicellulose and lignin characteristic peaks, improving the thermal stability of the treated MF/PLA composite. Thus, compared to a pristine sample, the resultant composites' higher mechanical strength and thermal stability demonstrated the significance of chemically treated natural fibres. The novelty of this research is the data on miswak fibre treatment, as no research has been found for this selected treated fibre.

Characterisation of Luffa cylindrica Fibre from Cameroon for Use in Composites: Effect of Alkaline Treatment

Characterisation of Luffa cylindrica Fibre from Cameroon for Use in Composites: Effect of Alkaline Treatment

Effect of alkaline treatment on hard vegetable shells on the properties of biobased abrasive wheels

One of challenges in composites research is to improve the quality of the interface fillers-matrix. The aim of this study was to evaluate the effect of sodium hydroxide (NaOH) treatment of coconut shells and palm kernel shells on the properties of wheels made. Shells were treated at concentrations of 1 %, 5 % and 10 % for 90 min before being used as abrasive grains to reinforce an epoxy matrix. The thermal degradation of shells was analyzed and the morphological study shows that the treatment modifies the surface of grains. The treatment led to a reduction in the water absorption rate of more than 10 % and the porosity of the grinding wheels of around 15 %. Statistical analysis showed that the treatment improved the material removal rate and wear resistance. The wheels treated with a concentration of 1 % gave better results with removal rates of 160 mg/s and wear rates of 3.86E-05 cm3/N.m.

Assessment of mechanical and physicochemical properties of palm fiber composites: Effect of alkaline treatment and volume alterations

This study assesses the impact of alkaline treatments and volume fractions on biocomposites composed of a high-density polyethylene (HDPE) matrix reinforced with date palm tree fibers (FPDS). Tensile tests were conducted on both untreated and NaOH-treated biocomposites. Additionally, fiber analysis was performed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results reveal higher strength and stiffness compared to HDPE, albeit with limited plasticity making the material brittle. The NaOH treatment enhances certain mechanical properties. Further assessments encompassed hardness, density, melt index, and Izod impact tests. Two volume fractions, 20% and 25%, of FPDS were tested. The study establishes a correlation between empirical predictions and artificial neural network (ANN) models. Notably, an ANN architecture consisting of two input factors, 10 hidden nodes, and one output provides the analysis of mechanical properties. This investigation highlights the potential of FPDS-reinforced HDPE biocomposites, emphasizing their mechanical performance under various treatments and fiber levels.

Effects of alkaline treatment and manufacturing process on mechanical and absorption properties of Wild Abyssinia Banana fiber reinforced epoxy composite

To enhance the properties of natural fiber composite, proper selection of an optimum alkaline concentration for fiber surface modifications and composite manufacturing techniques are the main criteria to be considered. This study examined how NaOH and manufacturing methodsaffect the mechanical and absorbency characteristics of a Wild Abyssinia Banana (WAB) epoxy composite. 2 %, 5 %, and 7 % (w/v) NaOH concentrations; hand-layup and hydraulic press manufacturing techniques have been considered. Petroleum, diesel, distilled, and artificial lake water (wastewater) were used for the absorption test. A 5 % NaOH treatment improves composite tensile, flexural, and impact strengths by 14.78 %, 8.59 %, and 29.63 %, respectively. Moreover, the 5 % NaOH treatment reduced the absorption rate of the WAB fiber composite. Hydraulic press manufactured untreated WAB fiber composite was observed to have 26.27 % and 13.45 % higher tensile and flexural strengths than hand layup. The treated WAB fiber-reinforced composite can be utilized in gas stations, home appliances, and finishing materials for construction applications.

Effects of alkaline treatment on the properties of pineapple (Ananas Comosus) leaf fiber (Palf) reinforced with tapioca-based bio resin (Cassava Starch)

The poor compatibility of natural fibers with hydrophobic matrices due to their hydrophilic nature has led researchers to improve their properties to enable better compatibility. Pineapple leaf fiber is one of the abundantly available natural fibers obtained from pineapple leaf. It has good chemical properties and strong admirable mechanical properties and can be used as a replacement for synthetic fibers despite the same deficiencies as other natural fibers. In this study, Pineapple leaf fiber was treated with Alkali at varying concentrations, temperatures, and times. Treated pineapple leaf fiber was reinforced with tapioca-based bio resin (cassava starch). This fiber was subjected to tensile testing and Fourier transform infrared (FTIR) spectroscopy. The results of FTIR indicated the various peaks in the absorbance versus wave number relation. The FTIR analysis of untreated pineapple leaf fiber indicated the presence of O-H stretch, N-H stretch, C ≡ stretch, C=O stretch, and H-C-H bond. The modification of fibers achieved by disruption of hydrogen bonding in the network structure was possible due to its treatment with alkali. Mechanical testing (tensile test) and FTIR were also used to know the effects of chemical treatment on the fibers. Alkali treatment improved the fiber properties as the concentration, temperature, and treatment time increased.

Effect of alkaline treatment on mechanical properties of palmyra and S-glass fiber reinforced epoxy nanocomposites

Effect of alkaline treatment on mechanical properties of palmyra and S-glass fiber reinforced epoxy nanocomposites

Effect of alkaline treatment on the single natural fiber strength using Weibull analysis probabilistic model

Natural fiber is becoming increasingly popular as a fiber reinforcement due to a rising emphasis on the manufacture of recyclable items and environmentally friendly. In this research aim to evaluate the mechanical characteristics of a single Napier fiber soaked in a solution of sodium hydroxide solutions with a concentration of 3, 6, and 9% for 20 h for light weight applications and this fiber could be used as reinforcement in polymer materials. The Weibull analysis was used to determine the predicted tensile strength and modulus. It was discovered that the alkaline treatment increased the fibers tensile strength and modulus by up to 82% and 77%, respectively. In conclusion, the alkaline treatment improved the tensile and modulus strength of the fiber. Additionally, this fiber has the potential to be used as reinforcement in polymers for applications in automobiles, furniture, and aerospace.

Effect of alkaline treatment on physical, structural, mechanical and thermal properties of Bambusa tulda (Northeast Indian species) based sustainable green composites

AbstractIn recent years, sustainable composites have gained increased attention due to various reasons, such as the depletion of non‐renewable resources, environmental sustainability, and the introduction of plastic pollution. The present work aims to develop biocomposites (with a maximum biological content of 61.78%) based on Bambusa tulda fiber and cashew‐nut shell oil‐based bio‐epoxy resin. Different concentrations of NaOH (2%, 4%, 6%, 8%, and 10%) are used to determine the most suitable NaOH concentration for bamboo fiber treatment. The effect of different treatment concentrations on bamboo fiber has been analyzed by performing single‐fiber tensile testing, fiber pull‐out testing, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, thermogravimetric analysis, and atomic force microscopy. The investigation revealed that the 6% NaOH‐treated fiber showed better thermo‐mechanical and interfacial properties. Various fiber weight fractions (10%, 20%, 30%, and 40%) are used for composite fabrication, and 30% fiber‐loaded composites show the best mechanical properties. The effect of chemical treatments on the mechanical properties of biocomposites was investigated using composites with a 30% fiber weight fraction and different NaOH treatments. It has been reported that 30% fiber weight fraction 6% NaOH treated composites show better tensile strength (132.916 MPa), tensile modulus (6.983 GPa), flexural strength (154.8 MPa), modulus (8.243 GPa), and impact strength (44.06 kJ/m2) with less moist absorption. The developed composites have shown excellent potential for advanced engineering applications when compared with previously reported composites.

Influence of the use of corn straw fibers to connect the interfacial transition zone with the mechanical properties of cemented coal gangue backfill

Cemented coal gangue backfill (CCGB) is a cement-based mixture containing coarse aggregates and is used to fill the goaves of underground coal mines. However, CCGB currently faces contradiction between its mechanical properties and material costs. Based on the technical idea of strengthening the weakest link of the mechanical properties (i.e., interface transition zone (ITZ)), a plant fiber reinforcement method for CCGB aimed at the ITZ was proposed. Moreover, using this method, aqueous-treated and alkaline-treated corn straw fibers, accounting for 1 %, 2 %, and 3 % of the mass of the coarse aggregate, were added to the CCGB. The effects of corn straw fibers on the uniaxial compressive strength, splitting tensile strength, shear strength, and drying shrinkage of CCGB were studied. The failure response characteristics of the specimen in the process of uniaxial compression were monitored using digital image correlation (DIC) and acoustic emission (AE) technology. The failure criterion of CCGB mixed with corn straw fiber was established based on the Mohr–Coulomb shear strength theory. The results demonstrated that adding 1 %–2 % corn straw fiber improved the mechanical properties of CCGB at an early age (before 28 days), but it was necessary to control the increase in drying shrinkage. The effect of alkaline treatment on corn straw fiber was better than that of aqueous treatment. This study will benefit the green development and resource utilization of solid biomass waste.

Effect of alkaline treatment on the physical and mechanical properties of borassus flabellifer leaf fiber

Effect of alkaline treatment on the physical and mechanical properties of borassus flabellifer leaf fiber

Effect of alkaline treatment on the thermal stability, degradation kinetics, and thermodynamic parameters of pineapple crown fibres

Pineapple crown is generally discarded as waste but constitutes an important source of lignocellulosic fibres. In this work, the effect of alkaline treatment on the chemical composition, pyrolysis kinetics, and thermodynamic characteristics of pineapple crown fibres (PCF) were investigated by chemical composition, Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), X-rays diffraction (XRD), and thermogravimetry. Chemical composition analysis indicated cellulose content increased from 18.93 to 57.00% after NaOH treatment. PCF fibre diameter was reduced from 6.1 to 4.3 μm after mercerization. The FTIR results confirmed the removal of non-cellulosic compounds. XRD analysis indicated fibre's crystallinity index rose from 53 to 62% in reason of NaOH treatment. Thermogravimetric results confirm that alkaline-treated PCF (ATPCF) presented higher thermal stability than non-treated PCF (NTPCF). The solid-state thermal degradation mechanism for NTPCF and ATPCF occurred by the diffusion process and random nucleation, respectively. The thermodynamic parameters of NTPCF indicated that a small amount of energy is required to obtain the reaction products and thus bioenergy production from NTPCF pyrolysis will be easier, while ATPCF required more energy to initiate a degradation reaction and could be used as filler in polymeric composites.

Insights into the effects of alkaline treatment and soaking duration on the properties of pterocarpus angolensis (mukwa) wood fibers

This work is focused on finding an ecological and economic soaking duration suitable for natural fibers, and in the process obtaining the best possible mukwa wood fibers for manufacturing polymeric composites. Waste mukwa wood fibers found in the semi-arid conditions of Botswana were subjected to 5 wt% NaOH at soaking durations of 1.5 h, 2.5 h, 4 h, 8 h, 12 h, and 24 h. The effect of soaking duration and alkaline treatment on the chemical components, crystallinity, surface morphology, character of molecular bonds, and thermal stability were studied through weight loss, chemical composition, scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR) and Thermogravimetric analysis (TGA) respectively. The results of this study found the 2.5 h soaking duration to be more economic, time saving, and effective in modifying mukwa wood fibers.

Effect of Alkaline Treatment on Physical and Tensile Properties of Areca Leaf Sheaths (ALSs) used for Biodegradable ALS Plate Production

This research evaluated the possibility of alkaline treatment to solve the problem of molding due to moisture during storage of areca leaf sheaths (ALSs) to be used for biodegradable ALS plate production. The effect of alkaline treatment on the properties of ALSs was studied. Sodium hydroxide (NaOH) and sodium bicarbonate (NaHCO3) were used as chemicals for surface treatment. The solution of NaOH and NaHCO3 was varied at 1%, 3%, and 5% w/v. Surface treatment with NaOH and NaHCO3 partially removed hemicellulose, cellulose, lignin, and impurities from the surface of the ALSs and increased the moisture resistance property of the ALSs. Treatment with NaOH made the ALSs’ surface rougher, whereas treatment with NaHCO3 had no effect on the surface of the ALSs. The decomposition temperature (Td2) of the NaOH-treated ALSs decreased by approximately 7.0 to 10.5%, while for the NaHCO3-treated ALSs it changed only slightly. The overall tensile properties of the NaOH-treated ALSs were better than those of the NaHCO3-treated ALSs. The surface treatment with 1% NaOH and 1% NaHCO3 increased the tensile modulus by 20.5% and 6.2%, respectively, as compared with the nontreated ALS. It was found that surface treatment with 1% NaOH and 1% NaHCO3 could create suitable conditions for ALS plate production. This work is a preliminary study; more research still needs to be done.

Effect of alkaline treatment on physical, mechanical, and thermal characteristics of jute filler reinforced epoxy composites

AbstractWith burgeoning environmental concerns worldwide, using natural fibers/fillers to produce composites rather than conventional fibers is on the rise. The current work focuses on the physical and thermomechanical characteristics of alkaline‐treated jute filler‐based epoxy composites. The composites have been prepared with different weight fraction of jute fillers (0%, 2.5%, 5%, 7.5%, 10%, and 12.5%) using hand layup process. The X‐ray diffraction and Fourier transform infrared spectroscopy analysis observed that the alkali treatment of jute fillers improved the crystallinity and molecular structure, enhancing the interfacial and molecular bond between fillers and matrix. The mechanical characterizations of developed composites analyzed that the inclusion of treated jute fillers strengthened the tensile and flexural properties. The 5% filler‐based composites have demonstrated maximum tensile strength (54.06 MPa) and modulus (3.12 GPa) with maximum flexural strength (67.55 MPa) and modulus (3.90 GPa). The viscoelastic characteristics of composites revealed that the 7.5% filler‐based composite has the highest storage modulus (3.75 GPa), loss modulus (0.496 GPa), and glass transition temperature (91°C) due to greater interfacial interactions of molecules. The weight loss and degradation of composites analyzed with thermogravimetric analysis, and observed better thermal stability with treated jute fillers. The morphological analysis at fracture surfaces analyzed the brittle catastrophic failure of composites. Therefore, the finding produced better specific strength and stiffness with greater thermal stability for electronics equipment, packaging, and transportation.

Effect of Alkaline Treatment and Fumigation (Fumigation) on the Mechanical Properties of Fiber Unsaturated Polyester-Cantula Composite with Compression Molding Method

<p>This research examines the strength of the UPRs-Cantula composite with the<br />addition of filler microcrystalline cellulose (MCC). Composites were created<br />with a volume fraction of 30% Vf and a 45° angle. This angle variation received<br />the same treatment as the others, including untreated, alkaline, and fumigation.<br />The treatment time for alkali treatment was 6 hours, while the treatment time<br />for fumigation was 10 hours. The strength of each angle variation was<br />determined, as well as its treatment of tensile strength, modulus of elasticity,<br />and Poisson's ratio UPRs-cantula composites. According to the results, the<br />alkali treatment produced the highest tensile strength and elastic modulus<br />values. The highest Poisson ratio value was discovered without treatment at a<br />45°. The alkaline treatment yielded the highest tensile strength and modulus of<br />elasticity test results. The pullout fiber fracture dominated the untreated<br />composite fracture, whereas the fiber breakage fracture dominated the alkaline<br />treatment.</p>

Development of soy protein concentrate/hemp fiber-based biocomposite foams: Effects of alkaline treatment and poly(lactic acid) coating

Petroleum-based foams are used in packaging applications where thermal insulation and shock absorption are needed. However, their associated environmental problems motivate the development of bio-based alternatives. Here, biocomposite foams were prepared using soy protein concentrate (SPC) and alkali-treated hemp fibers. The hemp fibers were treated with 6% NaOH to remove non-cellulose components. The foams were coated by dipping in a poly(lactic acid) (PLA) solution. A concentration of 4% PLA was determined to be optimal for the coating. The mechanical and water barrier properties of the PLA-coated foams were evaluated. The compression modulus, compression strength, and bulk density of the PLA-coated foams were 1045.7 kPa, 2022.5 kPa, and 118.6 mg/mL, respectively, being significantly higher than those of the uncoated foams (404.0 kPa, 590.7 kPa, and 69.4 mg/mL). The moisture uptake and water uptake of the PLA-coated foams were significantly decreased by the coating procedure, indicating 16.2% and 138.3%, respectively. By contrast, the uncoated foams had a moisture uptake and water uptake of 31.8% and 1399.3%, respectively. The observed improvement in mechanical and water barrier properties is likely due to the hydrophobic nature of PLA. • Biobased foams were made using soy protein concentrate and hemp fibers. • The hemp fibers were treated with 6% NaOH to remove non-cellulose components. • The foams were coated with 4% polylactic acid (PLA). • The PLA-coated foams showed enhanced mechanical properties and water resistance.

Effect of Water Absorption on the Mechanical Properties of Alkaline Treated Bamboo and Flax Fiber Reinforced Epoxy Composites

Untreated and alkaline treated bamboo and flax fiber reinforced epoxy composites are processed using a hand layup process. The effect of alkaline treatment on the mechanical properties of the composites has been analysed. Alkaline treatment of the fiber has enhanced the mechanical properties of the developed composites. Composite reinforced with 5 % NaOH treated fiber show better performance when compared with untreated fiber reinforced composites. Alkaline treatment of the bamboo and flax fiber with 5 % NaOH has improved the hardness by 3.57 and 2.43 %, tensile strength by 47 and 20.72 % and flexural strength by 7.36 and 13.85 % in bamboo and flax fiber reinforced composites, respectively. The increase in the percentage NaOH in the alkaline treatment of the fibers resulted in weakening of fiber resulting in a drop in the properties of the developed composites. Water absorption tests of the developed composites were conducted as per ASTM D570 by immersion in distilled water at room temperature. The influence of water absorption on mechanical properties of developed composites is also examined. The quantity of water absorption and diffusion coefficient are reduced with alkaline treatment of fiber. Mechanical properties of the composite were found to decrease by the water absorption, which can be controlled by alkaline treatment of fiber and thereby reducing water absorption rate and improve the mechanical properties of the composites.
 HIGHLIGHTS
 
 Reinforcing natural fiber in polymer resin is highly beneficial because it helps to improves the strength and toughness of the polymer
 Moisture absorption rate and lack of interfacial adhesion between the polymer and natural fiber made natural fiber reinforced composites less attractive compared to synthetic fiber reinforced composites
 Alkaline treatment of the natural fiber increases the fiber surface roughness, which results in improved mechanical interlock between fiber and matrix, resulting in improved mechanical and water resistance properties of the developed composites
 
 GRAPHICAL ABSTRACT

The Influence of Filler Loading and Alkaline Treatment on the Mechanical Properties of Palm Kernel Cake Filler Reinforced Epoxy Composites.

The manufacturing of materials, in conjunction with green technology, emphasises the need to employ renewable resources to ensure long-term sustainability. Re-exploring renewable elements that can be employed as reinforcing materials in polymer composites has been a major endeavour. The research goal is to determine how well palm kernel cake filler (PKCF) performs in reinforced epoxy composites. In this study, PKCF with 100 mesh was mixed with epoxy resin (ER) in various ratios ranging from 10% to 40% by weight. Hand lay-up with an open mould is proposed as a method for fabricating the specimen test. Surface modification of PKCF with varying concentrations of NaOH (5 wt.% and 10 wt.%) will be contrasted with the untreated samples. Using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC), the effect of alkaline treatment will be examined. The tensile and maximum flexural strength of the untreated PKCF/ER composite were determined in this work, with a 30 wt.% of PKCF having the highest tensile strength of 31.20 MPa and the highest flexural strength of 39.70 MPa. The tensile and flexural strength were reduced to 22.90 MPa and 30.50 MPa, respectively, when the filler loading was raised to 40 wt.%. A 5 wt.% alkali treatment for 1 h improved the composites’ mechanical characteristics. Lastly, an alkali treatment can aid in the resolution of the problem of inadequate matrix and filler interaction. Alkaline treatment is a popular and effective method for reducing the hydroxyl group in fillers and, thus, improving interfacial bonding. Overall, palm kernel cake is a promising material used as a filler in polymer composites.

Effect of alkaline treatment with sodium hydroxide on wettability and bioactivity of some commercial dental implants

Aim/Objectives The aim of this study was conducted to evaluate the effect of NaOH alkaline treatment on wettability and bioactivity of some commercial dental implants. Background The surface of titanium dental implants plays an important role in their success. Wettability is one of the crucial surface characteristics for osseointegration. Methods In this study, three commercial titanium dental implants are grouped by their types into 3 groups (n=10). Each group is divided into 2 subgroups (n=5) according to alkaline treatment. Each experimental specimen is immersed in 5 mL of 5M NaOH solution for 24h at 60°C, then put in an incubator for 24 h to dry at 40°C. All specimens are subjected to surface wettability test through measuring static contact angle (CA) by sessile drop technique and in vitro bioactivity test through immersion into a simulated body fluid (SBF) at 37°C and 7.4p H for 7 days. Then characterized by Scanning Electron Microscope and Energy Dispersive X-ray. Student t-test is used for pair-wise comparisons. The significance level is set at P≤0.05. Results/Conclusions The alkaline surface treatment of Ti dental implants significantly enhances their surface wettability and bioactivity by formation of a porous network structure at a nano scale from sodium titanate hydrogel layer on the surface.