Chemical Retting Research Articles

Influence of the extraction method on the chemical, physical and mechanical characteristics of oil palm (Elaeis guineensis) petiole fibers for the reinforcement of composite materials

For their use in polymer and composite materials engineering, and with a view to sustainable development, a great deal of work has been carried out with the aim of describing the properties of plant fibers. This work presents the effects of the extraction method on the chemical, physical and mechanical properties of oil palm petiole fibers (OPPF). To this end, the FPPH to be analyzed were obtained by water retting and chemical retting with soda (5% solution). Their physico-chemical and mechanical characteristics were then studied and compared. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the existence of the main components of lignocellulosic fiber (lignin, cellulose and hemicellulose). Lignin was reduced by 22.74%, hemicellulose by 27.33% and cellulose by 16.87% compared to water retting. XRD revealed a crystallinity index of 58.66% for fibers extracted with a 5% sodium solution and 58.51% for fibers extracted with water retting. Soda retting reduces density by 3%. Tensile tests revealed an average tensile strength of 156.082 MPa for water-rubbed fibers and 205.875 MPa for soda-rubbed fibers, Young’s modulus of 3.432 GPa for water-rubbed fibers and 5.346 GPa for soda-rubbed fibers. Elongation at break for FPPH extracted by water retting was 5.178% and 4.41% respectively. This shows that the extraction method affects mechanical properties (flexibility and stiffness) and should be chosen according to the desired characteristic.

Optimization of the novel jute retting process to enhance the fiber quality for textile applications

This study introduces an innovative chemical retting approach, systematically optimized via Grey relational analysis, to achieve jute fibers that exhibit desirable characteristics of softness, high tensile strength, and suitability for spinning, with a particular focus on their application in the apparel industry. In this study, the effect of alkali treatment (alkali concentration, temperature and duration of retting) on jute fiber's chemical composition and mechanical characteristics was investigated. Jute fibers were treated at three concentrations (5 %, 10 %, 15 %) of alkali, at three different temperature (30 °C, 60 °C, & 90 °C) and for three different retting duration (12 h, 24 h, & 36 h). The surface morphology and crystallinity of fibers were analyzed using optical microscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The fiber linear density and mechanical characteristics were also tested. The multi-response optimization of all the factors and the responses was investigated using the Grey relational analysis. The results showed that the fiber surface morphology and crystallinity increase with an increase in alkali concentration, retting time, and temperature. Chemical retting treatment also improved the fiber linear density and tensile strength. The finest fibers which were obtained in this research had a linear density of 2.18 Tex with a tenacity of 53.02 cN/tex and elongation of 4.54 %. The spinnable jute fibers were achieved after this treatment with excellent characteristics.

Enhancing structural, thermal, and mechanical properties of Acacia pennata natural fibers through benzoyl chloride treatment for construction applications

In recent years, there has been growing interest in exploring natural fiber reinforced composites as potential alternatives to conventional materials in various structural applications. The aim of this study on Acacia pennata fibers (APFs) and treating them with benzoyl chloride was to explore their potential as reinforcement in construction-related materials. The aim was to investigate the physico-chemical, thermal, and mechanical properties of these fibers to understand their suitability for applications in concrete reinforcement, retrofitting, roofing, and wall panels. By enhancing the understanding of the treated fibers' characteristics, this study contributes to the development of sustainable and high-performance construction materials. The fibers were extracted using both water retting and chemical retting methods. The physico-chemical properties of the fibers were assessed through X-ray diffraction (XRD) analysis, which determined a calculated crystalline index (CI) of 72.14% and a crystalline size of 2.6 nm. Thermo-gravimetric analysis was conducted to evaluate the thermal stability of the APFs, revealing a temperature of 366°C and a maximum degradation temperature of 226.7°C. Mechanical analysis included measurements of the APFs' tensile strength (467.86 MPa), tensile modulus (14.62 GPa), microfibrillar angle (14.79˚), and elongation at break (3.2%). The findings derived from these analyses suggest that the APFs that underwent treatment exhibit desirable mechanical characteristics, rendering them a viable option for utilization in construction-related materials like reinforcement in concrete, retrofitting, roofing and wall Pannels. This research presents a novel exploration of Acacia pennata fibers (APFs) treated with benzoyl chloride, aiming to establish their potential as reinforcements for construction materials. While natural fiber-reinforced composites have drawn interest, the unique application of APFs in construction and their treatment with benzoyl chloride to enhance properties remain relatively unexplored in the literature. This study fills a significant gap and contributes to the advancement of sustainable and high-performance construction materials by utilizing treated APFs. The results highlight the remarkable capability of these fibers to enhance the properties of composite materials in the construction industry.

Extraction of natural cellulosic fiber from Myriostachia wightiana stems using chemical retting and its characterization for bio-composite applications

Extraction of natural cellulosic fiber from Myriostachia wightiana stems using chemical retting and its characterization for bio-composite applications

Extraction and characterization of a novel tropical fibre Megaphrynium macrostachyum as a biosourced reinforcement for gypsum-based biocomposites

Identifying the potential of new bast fibres is a solution for diversifying biobased reinforcements and replacing environmentally harmful synthetic fibres. In this study, fibres were extracted from Megaphrynium macrostachyum stems by biological and chemical retting. The chemical fibres were bleached with a 2.5wt% sodium hypochlorite (NaClO) solution. The biological, chemical and bleached fibres were analysed from a chemical, morphological, physical, mechanical and thermal point of view. The possibility of using these fibres as reinforcement in gypsum-based biocomposites for construction was analysed by three-point bending tests. Chemical analysis revealed a cellulose content of more than 56 wt% within the usual range (50-85 wt%) for reinforcing fibres. SEM images showed that bleaching cleans the surface of the fibres. Physical analysis by gravimetric analysis showed that the bleached fibre had the lowest density (1.01 g.cm−3), fineness (5.2tex) and water absorption (64wt%). In addition, the highest thermal stability (237°C) was obtained for the chemical fibre. Young’s modulus and tensile strength, evaluated according to ASTM D3822-07, were dispersed and depended on the fibre diameter, and the highest values were obtained for the chemical fibre (6.4 GPa and 251 MPa). In contrast, gypsum composites with a volume fraction of 1.5% bleached chemical fibre had the highest stiffness (258 MPa) and flexural strength (5 MPa). The results obtained for each fibre type are relatively close to those of other fibres in the literature, indicating that all three fibre types studied can be used as alternative raw materials for the manufacture of gypsum-based biocomposites.

Types, stages and mechanism of action of Jute retting: An overview

Some factors hastening up retting process which are- retting water, retting in already used water, harvesting time, climate conditions like high temperatures, deep water (too deep water will delay retting, addition of chemicals, materials used as weights on Jak, method of retting, variety of jute, method of fiber extraction, stage of harvesting, period of retting, etc. There are few methods of retting available which are- conventional method of whole plant retting, chemical retting, microbial retting, mechano-microbial retting and In-situ retting with microbial consortium. There are three sequential stages in retting (based on the morphological modification, dynamics of pH and various enzymes related to them during the entire jute retting process): Stage 1 (Initial retting stage); Stage 2 (Middle retting stage) and Stage 3 (Final retting stage).

DEVELOPMENT OF CALOTROPIS/COTTON BLENDED YARN AND ITS PROPERTIES

Natural fibres, which are an important part of the human environment, and also valuable raw materials used for textile and non-textile production. The use of natural fibres instead of materials such as glass fibres, carbon, and talc provides several advantages including low density, low cost, good specific mechanical properties, and biodegradability. Blending is the mixing of two or more masses of fibres so that the resulting mixture has the characteristics of the average of the component items. The most important reason for blending is the creation of new and more desirable effects.This study was conducted in Assam in the year 2021. Four different methods were used for the extraction of fibre from the peeled bark of tender stems of Calotropis gigantea plants and among which chemical retting with alkali (NaOH) was selected for the study. The study was carried out by blending Calotropis and cotton in three proportions (25:75, 50:50, and 75:25 ratios) and the properties of blended yarns were investigated. It was observed that the Cotton yarn has given a higher amount of TPI and extension than the blended yarn. Fifty: fifty blended yarn have higher tensile stress, and higher lea strength than the other yarn, and were the finest among the blends.The cotton yarn had a finer count, high lea strength, and more count strength product compared to blended yarns. It was also noticed that 50:50 blended yarn had high count strength product than the other combination.

Effect of retting methods on molecular weight of Agave atroverance fibers

This study was undertaken to investigate the effect of retting method on the molecular weight of different portion of the Agave atroverance fiber (top, middle and bottom) extracted by different retting techniques. The raw fibers from Agave atroverance plant were retted by biological and chemical (degumming) retting methods. In biological retting method both the stagnant and boil water were utilized and in chemical retting method, the extracted fibres were treated with the 5% NaOH. Agave atroverance fiber is not purely cellulosic fiber. Percentage composition of different portion of the raw fiber was also determined. It contains α-cellulose, hemicellulose, nitrogenous matter, mineral matters and miscellaneous. The retted fibres were tested for determination of molecular weight. The percentage loss of molecular weight was found to be more in case of chemically retted fibres owing to the enhanced digestibility of lignocellulosic material by 4% sodium chlorite solution. Contrary to this, biological retting showed higher molecular weight due to the presence of higher cellulosic matter and removal of pectic substabces.

Stinging nettle fibres extraction and characterization using chemical retting method and influence of tensile properties

The tensile strength properties of stinging nettle fibres treated with sodium hydroxide and sodium chlorite solutions have been studied in this research. The fibre in stinging nettle bark is related to jute, hemp and flax, and it has a lot of potential in the green textile industries. Nettle fibres are naturally derived high-strength nettle yarn for the production of home textiles, handicrafts, and ropes. It is a high fibre-yielding plant that grows naturally in the Himalayan areas, Nagaland. In this study, nettle fibre samples were soaked in 4 % sodium hydroxide (NaOH) and 1% sodium chlorite (NaClO2) solutions at a 100 °C temperature for 90 min. The nettle fibre samples were prepared and tested as detailed in the ASTM D3822 standards. So that, the average tensile strength of treated nettle fibres was increased by 27.17 % compared with untreated fibre. The mild alkali treatment increases tensile strength, cellulose content and decrease elongation break acts to be due to fibre extraction and degradation of non-cellulosic materials such as hemicellulose, lignin, and pectin. Compared to untreated nettle fibre, the average Young's modulus of sodium hydroxide-chlorite treated fibre was increased by 26.79 %. Moisture sorption analysis, Fourier transform infra-red spectroscopy (FTIR), single fibre tensile strength, and physical properties were used to understand the properties of untreated and treated nettle fibres.

Extraction and characterization of cellulosic nanocrystals from stems of the reed plant large-leaved cattail (Typha latifolia)

Cellulose is the most abundant renewable resource in nature and has many industrial uses because of its promising characteristics. The broad-leaved reed is a plant species of the family Typha latifolia, widespread in arid regions, and has good potential for industrial use. In this study, highly crystalline cellulose microfibers were extracted from the reed stems as a new renewable source. The materials were subjected to a dewaxing process and then the microfibers were extracted using 7% sodium hydroxide, followed by a bleaching process. The extracted cellulose microfibers were distinguished by scanning electron microscopy SEM, Fourier transform infrared spectroscopy FTIR, X-ray diffraction analysis XRD, and thermo-gravimetric analysis TGA. In the retting process, the IR peaks clearly show that there has been a removal of non-fibrous material. Using the X-ray diffraction technique, a crystallinity of 77.8 % with a crystallinity index of 0.521 was observed. The fiber spikes from the SEM images confirm that by increasing the chemical concentration and treatment time, there was more removal of non-fibrous cellulose and fibrillation found. Typha leaves are a rich source of cellulosic fiber tows and these fibers can also be extracted by chemical retting method and they are easily biodegradable and environmentally friendly.

Extraction and characterization of indigenous Ethiopian castor oil bast fibre

Bast natural fibers have gained importance in the recent years mainly due to their ecofriendliness and their potential availability as raw materials for textile industries. In the present study extraction and characterization of fibers from the stem of Ethiopian indigenous castor oil plant is conducted for possible utilization in textile and related industrial applications. Among the different fiber extraction methods chemical retting using aqueous alkaline media (NaOH) is used for the extraction of the bast fiber. In this study the extraction was carried out by setting appropriate retting conditions of concentration of alkali, temperature and time. The extracted fibers for experimental analysis under the combined conditions were tested for chemical composition, gross morphology, mechanical and thermal properties. The analysis on chemical composition revealed that the castor oil bast [COB] fiber is composed of 64.5–67.3% cellulose, 16.4–21.5% hemicellulose, 15.8–17.2% lignin, 0.3–0.9% extractive with 4.9–5.3% ash content. FTIR spectra of the extracted fibers also confirmed the presence of cellulose, hemicellulose, lignin and extractives. Analysis on dimensional characteristics of the fiber showed that the extracted fiber has a diameter of 14.2–30.8 µm and fineness of 4.5–13.5 tex with fiber length ranging from 1.3 to 10 cm; the moisture content and moisture regain of the fiber are 7.0–9% and 8.1–10% respectively. Tests on mechanical properties of the extracted COB fiber show a tensile strength of 250–700 MPa with tenacity in the range of 57.80–86.89 cN/tex, elongation of 1.2–5% and elastic modulus of 2114.55–2625.44 cN/tex. TGA results for thermal property analysis indicated that the COB fiber has very good thermal stability with a thermal decomposition temperature in the range of 386.5–498.9 °C. The reasonably high cellulose content, good dimensional and moisture characteristics of COB fiber and its very good mechanical and thermal properties in comparison with conventional natural fibers such as jute, flax, hemp and cotton indicate the possibility for versatile conventional and non-conventional applications of COB fiber such as in textiles and in fiber reinforced composites.

Characterization of Cellulosic Leaf Fiber from the Typha Angustifolia Plant

ABSTRACT Typha leaves are a rich source of fiber cables and these fibers can also be extracted by chemical retting method and these are easily bio-degradable, and eco-friendly. The main objective of present work is to assess the fiber characteristics such as FTIR, XRD, TGA, SEM, and single fiber tensile properties by varying fiber extraction parameters. In the retting process, IR peaks clearly shows that there was a removal nonfibrous material (NFM). Using X-ray diffraction technique 67.61% crystallinity with a crystallinity index of 0.521 was observed. Fiber tips of SEM images confirm that by increase in chemical concentration and treatment time, there was more removal of NFM and fibrillation found. For the fiber extraction mainly two treatment particulars were varied i.e. sodium hydroxide (10, 20, and 30 gpl) and time (3, 4, 5, and 6 h). Out of various retting conditions, at 20 gpl with 4 and 5 h treatment time shows an excellent tensile strength of single fiber, i.e. 125 Mpa and 179.82 Mpa and 30 gpl with 4 hrs and 5 h observed moderate strength, i.e. 106.03 Mpa and 122.69 Mpa respectively.

Structural and physical characteristics of the yucca fiber

Yucca fiber is a natural cellulose fiber that can be extracted from the Yucca plant leaves by retting. The physical properties of the Yucca fiber are extremely sensitive to the retting conditions. This research was designed to study the effects of chemical retting on the structural and properties of this fiber. Chemical retting was done by soaking the Yucca leaf in 10 to 150 g/l sodium hydroxide concentration at 80 to 100 °C for 60 to 240 min. Fiber characteristics such as fineness, tenacity, functional groups, crystallinity, thermal degradation, and surface morphology were then investigated. The Yucca fibers exhibited high crystallinity (56–66%), high tenacity (36–46 cN/tex), and low linear density (3–5 tex). It was also found that the elementary fiber had a mean diameter of about 1.2 [Formula: see text] and a helical structure of square-shaped spires. The thermogravimetric analysis also indicated that the Yucca fiber had the thermal stability of up to 250 °C. Based on the findings, the Yucca fiber may be suitable for various applications such as a reinforcement material in the composites applications and can be turned to yarn for textile applications.

Flexural modulus of epoxy composite reinforced with Arecanut husk fibre (AHF): A mechanics approach

Arecanut Husk Fibre (AHF) is an agricultural waste material. Polymer composites prepared with AHF as reinforcing material avoids dumping of arecanut husk onto bare land. AHF contributes to the development of innovative products having low environmental impact. These polymer composites are cost-effective and have low-density. Composites manufactured using polymers and natural fibre are widely used in aerospace, automobile, construction and marine structural applications. AHF was extracted by chemical retting process using 6% sodium hydroxide solution. The present research focuses on composite panel preparation using epoxy reinforced with treated AHF (15% by weight of composite) and flexural characterization of the composite. Composites were made with three-layered arrangement of AHF threads. In the current study, flexural modulus of AHF composite panels is determined by conducting dynamic flexural tests with fixed–fixed support condition and at different loading frequencies. The flexural modulus of the composite material is calculated using Euler- Bernoulli bending theory and results are compared with existing literature.

Improvement of water quality of remnant from chemical retting of coconut fibre through electrocoagulation and activated carbon treatment

Remnant obtained from chemical retting of coconut fibre was found to have an exorbitant COD, BOD, TDS, sulphide content having blackish brown colour. Traditional (physico-chemical) treatment could not reduce its COD, TDS, colour substantially. Further, the traditional method was lengthy, consumed huge chemicals and time. Present paper reports a quicker, simpler, economic i.e., an industrially viable method to separate the chemicals and biomass by employing electrocoagulation (EC). The performance of EC was analyzed by keeping temperature, and pH of remnant constant, while varying current flow (100–2000 mA), time (15–90 min) and number of iron electrodes (2,4,6). Efficacy of EC was evaluated in terms of reduction in conductivity, pH, TDS, COD, TOC, colour and quantity of sludge generated from the wastewater. Six electrodes with 2000 mA current flow for 90 min were found to give noticeable reduction on COD (92.8%), TOC (56%), TDS (99%), and colour. To reduce pH, and TDS to an acceptable level, filtration with activated charcoal was attempted on recovered water from EC. Resultant water was also found to have acceptable LC50 value for safe disposal. Carbon content (53%) in the sludge was high, contained lignin and cellulose whiskers also, as revealed from the EDX and FTIR, SEM respectively. Cost of EC ($ 0.087 USD/L) was found to be much less as compared to traditional method ($ 0.384 USD/L).

Morphological and Thermal Analysis of Retted Rattan Waste Fibers

The aim of this paper is to study the effects of retting processes on rattan waste fibers, specifically on its morphological and thermal properties. The fibers were prepared for water and chemical retting processes, and were labelled as RF, WRF and CRF for untreated rattan, water-retted rattan and chemical-retted rattan, respectively. Then, these fibers were mixed and hot-pressed into composite boards, which were analyzed for their thermal, strength and morphology properties. Comparatively from Thermogravimetric Analysis (TGA), the WRF has higher thermal stability at lower decomposition temperature, yet the CRF has slightly lower thermal stability compared to RF. It also shows that the retting processes have reduced moisture content inside rattan waste fibers. All the fibers underwent an endothermic process in Differential Scanning Calorimetry (DSC) analysis, where it also displayed that the melting point of RWF, WRF and CRF were 177.80 °C, 183.43 °C, 187.27 °C, respectively. Tensile tests showed that the water retting process had improved the strength properties of WRF/PLA composite board compared other boards. It is supported through the morphological structures of boards. The RF/PLA and WRF/PLA displayed smooth board surfaces indicating the better bonding between fiber and matrix. The removal of certain components such as hemicellulose, lignin and other impurities, obviously can be seen from the morphology of WRF and CRF. It resulted in coarser and rougher fiber surfaces that facilitated good bonding between fibers and matrix as well as reasonable thermal stability. Thus, it is recommended to apply the water retting process before proceeding with fabrication of composite boards.

Influence of fiber treatment on dimensional stabilities of rattan waste composite boards

The main drawback of using natural fibers in composite boards is its hydrophilic properties which absorb a high volume of moisture. This results in low dimensional stability of the produced composite boards. Hence, the purpose of this study is to investigate the effects of fibers’ treatment processes of the rattan waste fibers on the dimensional stabilities of composite boards. The collected fibers underwent two types of retting processes, namely a water treatment and alkaline treatment retting processes; where the fibers were soaked in water and a 1% sodium hydroxide (NaOH) solution, respectively. The fibers were dried and mixed with poly(lactic) acid (PLA) pellets with ratio of 30% fibers: 70% matrix; before being fabricated into composite boards via a hot-pressing process and were labelled as RF/PLA, WRF/PLA, CRF/PLA for untreated rattan, rattan treated by water retting, rattan treated by chemical retting, respectively. The produced composite boards were cut and soaked in water for 24 hours for dimensional stability in terms of water absorption and thickness swelling tests. The results showed that WRF/PLA has the lowest water absorption (3.2%), and the CRF/PLA had the highest water absorption (23.2%). The thickness swelling showed a similar trend as water absorption. The presence of void contents and fibers damaged the insides of the boards, which contributed to low dimensional stabilities of the composite boards. It can be concluded that water retting facilitated in improving dimensional stability of the produced composite board.

Effect of retting methods on properties ofDhaincha fibres

The dried ribbons of Sesbania aculeata (Dhaincha) plant were retted by chemical and biological retting methods. In first chemical retting method, the fibres were treated with the combination of EDTA and NaOH whereas in second method pretreated with HCl followed by NaOH; In biological retting method both the stagnant and running water methods were utilized. The retted fibres were tested for physical properties such as, moisture content and weightloss. The percentage weight loss was found to be more in case of chemically retted fibres owing to the enhanced digestibility of lignocellulosic material by the alkali. Contrary to this, biological retting showed higher moisture content due to the presence of non cellulosic matter. Overall, the properties exhibited by Sesbania aculeata fibres obtained after 15 days of stagnant water retting was comparatively good as compared to other retting methods in terms of weight loss and moisture content.

Evaluation and Impact Factors of the Mechanical Properties of Phloem Bundle Fibers Obtained from Kenaf Germplasm

ABSTRACTThe mechanical properties of kenaf phloem bundle fibers are valuable for reinforced composites or boards, more so than similar materials also used in textile or papermaking applications. 55 kenaf germplasm studied here showed an average phloem bundle fiber tensile strength of 643.6 MPa and an average elastic modulus of 23.3 GPa after chemical retting treatment. 19 of these kenaf germplasm had fiber tensile strengths >700 MPa, which can be attributed to intensive breeding programs. The fiber tensile strength and elastic modulus of kenaf germplasm had a significant positive correlation, but there was no such correlation between a fiber’s mechanical properties and its diameter or agronomic characteristics. Among 56 hybridized combination F1 generations, the highest tensile strength was 928.3 MPa from a combination of No.30 of Xinan Wuchi × Guatemala 4. Therefore, breeding and screening are both useful for improving the mechanical properties of kenaf phloem bundle fibers. However, the effects of the used bundle fiber preparation method or cultivation year on the fiber’s mechanical properties were more pronounced than those of the type of kenaf germplasm or breeding operation used. The mechanical properties of kenaf phloem bundle fibers treated by chemical retting were superior to those treated using natural retting.

Study on Reuse of Coconut Fiber Chemical Retting Bath. Part II---Recovery and Characterization of Lignin

ABSTRACTStudy aimed at recovery of lignin from the reused residual liquor of chemical retting bath of coconut fiber caused by partial delignification to make it soft. The lignin of 8.9% was obtained after recovery (maintaining pH 2.0 for 1 h at ambient temperature) and further purification. Extracted lignin is characterized through FTIR, TGA and particle size analysis. FTIR showed absence of polysaccharides in purified lignin. TGA indicates presence of higher methyl-aryl ether groups than aromatic groups in lignin of coconut fibre. Analysis reveals about 91% of particles in the rage of 1–500 µm, which shows its good dispersiblity in fluid. Recovery of lignin associated with two benefits i.e., diversified use of extracted pure lignin and reduction of organic load of the waste liquor to make it suitable for discharge.