Mechanical and Structural Characterization of Pineapple Leaf Fiber

Chemically Modified Pineapple Leaf Fibre as a Filler of Polyurethane-Based Composites

Pineapple leaf fibres represent a biodegradable raw material sourced from renewable resources whose use contributes to reducing the carbon footprint and limiting the amount of waste generated. Their potential applications can effectively decrease the industry's dependence on plastics and support sustainable development, which should accompany the production of modern materials. In this study, polyurethane-based composites reinforced with various types of natural cellulose fillers were developed and investigated. Microcrystalline cellulose and unmodified and chemically modified pineapple leaf fibres were used as reinforcements. The mechanical and thermal properties of the produced materials were determined and compared. The results of the tests indicated that both microcrystalline cellulose and pineapple leaf fibres contributed to a reduction in the mechanical properties of polyurethane. A varying impact of fillers on the Young's modulus of the biocomposites was observed. The presence of natural modifiers influenced an increase in the melting temperature of the composite compared to the pure polyurethane. Integration of natural pineapple fibres into composite represents a step toward a more sustainable future, combining economic benefits with environmental care. The mechanical characteristics of composite materials were enhanced by modified fibres, compared to their unmodified counterparts. This improvement comes from the unique structural properties of the modified fibres. When polyurethane (PU) is used as the matrix material, it effectively fills the interfibrillar voids, creating a more cohesive bond between the components.

Synergistic action of multiple degumming-related enzymes secreted by Bacillus subtilis XW-18: Decisive factor for driving the bio-degumming process of raw pineapple leaves

Degumming, a process of removing gummy substances surrounding fiber, plays a crucial role in preparing plant fibers. This study clearly clarified that the multiple degumming enzymes by Bacillus subtilis XW-18 acted as a decisive factor for driving bio-degumming process of raw pineapple leaves. Firstly, PCR analysis verified that B. subtilis XW-18 could produce multiple degumming-related enzymes, including 9, 24, and 1 genes encoding pectin-degrading enzymes, hemicellulose-degrading enzymes, and lignin-degrading enzyme, respectively. Subsequently, the pectin acetylesterase (PAE) from B. subtilis XW-18 was expressed in B. subtilis WB600. It was found that the engineered B. subtilis pMA5-PAE had a certain degumming effect on crushed pineapple leaves and manually extracted pineapple leaf fibers, but failed to function on raw pineapple leaves. In contrast, the wild strain B. subtilis XW-18 exerted an effective degumming effect on raw pineapple leaves. Therefore, degumming of raw pineapple leaves requires the synergistic action of multiple degumming enzymes. By using the commercial degumming enzymes for degumming of the manual extracted pineapple leaf fibers, results showed that the combination of pectinase, xylanase, and mannanase achieved a lower residual gum content than each single enzyme, further confirmed that the presence of multiple degumming enzymes contributed to a more efficient degumming progress.

An efficient preparation process of sisal fibers via the specialized retting microorganisms: Based on the ideal combination of degumming-related enzymes for the effective removal of non-cellulosic macromolecules

Bioaugmentation retting with the specialized pectinolytic and xylanolytic microorganisms can accelerate the removal of non-cellulosic macromolecules around plant fibers, thus shortening retting time and facilitating fiber quality. Currently, few specialized microorganisms have been explored for the retting of sisal fibers. The present study excavated the retting fungi including Aspergillus micronesiensis HD 3-6, Penicillium citrinum HD 3-12-3, and Cladosporium sp. HD 4-13 from the region-specific soil samples of planting sisal, and investigated their bioaugmentation retting effects on raw sisal leaves. Results showed that combination of the three fungi achieved the most excellent degumming efficiency (13.69 % of residual gum in sisal fibers) and the highest fiber yield (4.47 %). Furthermore, this fungi combination had the ideal enzymatic hydrolysis features with high activities of pectinase, xylanase and mannanase whereas a low activity of cellulase during the whole retting process, thus endowing the prepared sisal fibers with the lowest mass percentage of non-cellulosic macromolecules (9.76 wt%) and the highest cellulose content (89.23 wt%). SEM and FT-IR analysis further verified that the non-cellulosic substances around sisal fibers were efficiently removed. In summary, the consortia of the three fungi achieved ideal degumming-related enzymes for the removal of non-cellulosic macromolecules, thus acquiring the efficient preparation of sisal fibers.

Mechanical Characterization, Water Absorption, and Thickness Swelling of Lightweight Pineapple Leaf/Ramie Fabric-Reinforced Polypropylene Hybrid Composites

Fiber-reinforced composites are among the recognized competing materials in various engineering applications. Ramie and pineapple leaf fibers are fascinating natural fibers due to their remarkable material properties. This research study aims to unveil the viability of hybridizing two kinds of lignocellulosic plant fiber fabrics in polymer composites. In this work, the hybrid composites were prepared with the aid of the hot compression technique. The mechanical, water-absorbing, and thickness swelling properties of ramie and pineapple leaf fiber fabric-reinforced polypropylene hybrid composites were identified. A comparison was made between non-hybrid and hybrid composites to demonstrate the hybridization effect. According to the findings, hybrid composites, particularly those containing ramie fiber as a skin layer, showed a prominent increase in mechanical strength. In comparison with non-hybrid pineapple leaf fabric-reinforced composites, the tensile, flexural, and Charpy impact strengths were enhanced by 52.10%, 18.78%, and 166.60%, respectively, when the outermost pineapple leaf fiber layers were superseded with ramie fabric. However, increasing the pineapple leaf fiber content reduced the water absorption and thickness swelling of the hybrid composites. Undeniably, these findings highlight the potential of hybrid composites to reach a balance in mechanical properties and water absorption while possessing eco-friendly characteristics.

Characterization of new cellulosic fiber derived from Lasia spinosa (L.) thwaites rhizome and its potential use as biodegradable textile material

Fibers extracted from Lasia spinosa (L.) thwaites (LS) were characterized to investigate their potential use as biodegradable textile materials. Mechanical and alkali extraction methods were followed to extract LS rhizome fibers. The morphological, physical, chemical, mechanical, and thermal properties of the mechanically extracted rhizome fibers from the commonly available LS species of Lamina-dissected type [LDT] and Sagittate type [SG] were investigated. No previous studies have been done to characterize the LS rhizome fibers. Examination of rhizome fiber morphology using scanning electron microscopy (SEM) revealed that fibers within the dispersed vascular bundles of the rhizome possess a natural crimp.The FTIR result confirmed that the fibers are rich in cellulose. X-RD results confirm a 43 % and 58 % crystallinity index of LDT and SG fibers, respectively, indicating higher amorphous regions and lower crystal phases. Moisture regain of 12.5 % and 14.5 %, single fiber tensile strength of 213.92 MPa and 216.97 MPa, elongation at break of 16.65 % and 17.67 %, and Young's modulus of 1.32 GPa and 1.26 GPa were observed for LDT and SG fibers respectively. Thermogravimetric analysis confirmed thermal stability up to 230 °C for both fiber types confirming their ability to withstand textile processing.

Extraction, characterization and properties evaluation of pineapple leaf fibers from Azores pineapple

Pineapple leaves can provide competitive and high-quality fibers for textile purposes. Despite pineapple being cultivated in the Portugues islands there is still a technology gap for the extraction and treatment of Pineapple Leaf Fibers (PALF) in Europe. Since Azorean Pineapple differs significantly from other plants in the bromeliad family, the properties and characterization of its leaf fibers were explored for the first time. Long fibers have been extracted by hand scraping and compared to biological retting at 25 °C for different time periods. It was explored the properties of PALF from plants of different ages (11- and 18-months) and from different zones of the leaves (beginning, middle, and tip). Physical-mechanical properties of Azores PALF were determined, including diameter, linear density, strength, Young's modulus, and elongation at break and characterized by ATR-FTIR, XRD, TGA/DTG, and FESEM to understand their chemical and morphological characteristics. While slight differences were observed between different ages, variations in physical-mechanical properties were notable among fibers extracted from different leaf positions. Extraction of Azores PALF through 25 °C biological retting for 14 days effectively eliminated non-fibrous matter and produced the thinnest and strongest fibers. These fibers ranged between 34.9 and 168.3 μm in diameter, 1.39 and 7.07 tex in linear mass density, 37-993 MPa in tensile strength, 1.0-3.9 % in elongation at break, and 2.4-21.8 GPa in Young's modulus.

Effect of chitosan-based bio coating on mechanical, structural and physical characteristics of microfiber based paper packaging: An alternative to wood pulp/plastic packaging

Limnocharis flava is a noxious aquatic weed that poses a threat to paddy cultivation. The high cellulose and low lignin contents in this plant make it a potential raw material for papermaking. Against this backdrop, this study was taken up to develop Limnocharis flava (LF) based sheets containing natural fibres from Banana (B), Pineapple (P), and Rice Straw (RS) as reinforcing agents. The influence of carboxymethyl cellulose (CMC) as a binder on the LF-based sheets was also studied. To enhance the mechanical and moisture resistance properties, a chitosan coating was provided to the sheets. Analytical tests for mechanical properties, water barrier properties, functional groups, structure and microstructure, thermal properties and biodegradability were performed. Among the samples, LF + B showed the highest tensile strength (34.86 Mpa) and bursting strength (13.055 kg/cm2), while LF + R had higher puncture and tearing strengths. Chitosan coating was found to enhance the sheets and improve the water barrier properties mechanically. The contact angle of LF + B increased from 91.6° to 110.65°, while the water vapour transmission rate of LF reduced from 532.18 to 404.47 on providing chitosan coating. The significant interactions of reinforcing agents were confirmed by the results of FTIR and that of the coating by the SEM micrographs. The LF-based sheets were also found to have decent thermal stability. The high value of the crystallinity index in LF + R samples supported their remarkable mechanical properties. This study proclaims the notable suitability of Limnocharis flava in manufacturing paper for packaging applications.

Comparative Study of Flax and Pineapple Leaf Fiber Reinforced Poly(butylene succinate): Effect of Fiber Content on Mechanical Properties

In this study, we compare the reinforcing efficiency of pineapple leaf fiber (PALF) and cultivated flax fiber in unidirectional poly(butylene succinate) composites. Flax, known for robust mechanical properties, is contrasted with PALF, a less studied but potentially sustainable alternative. Short fibers (6 mm) were incorporated at 10 and 20% wt. levels. After two-roll mill mixing, uniaxially aligned prepreg sheets were compression molded into composites. At 10 wt.%, PALF and flax exhibited virtually the same stress-strain curve. Interestingly, PALF excelled at 20 wt.%, defying its inherently lower tensile properties compared to flax. PALF/PBS reached 70.7 MPa flexural strength, 2.0 GPa flexural modulus, and 107.3 °C heat distortion temperature. Comparable values for flax/PBS were 57.8 MPa, 1.7 GPa, and 103.7 °C. X-ray pole figures indicated similar matrix orientations in both composites. An analysis of extracted fibers revealed differences in breakage behavior. This study highlights the potential of PALF as a sustainable reinforcement option. Encouraging the use of PALF in high-performance bio-composites aligns with environmental goals.

Investigating the Mechanical, Thermal, and Crystalline Properties of Raw and Potassium Hydroxide Treated Butea Parviflora Fibers for Green Polymer Composites

The only biotic factor that can satisfy the needs of human species are plants. In order to minimize plastic usage and spread an immediate require of environmental awareness, the globe urges for the development of green composite materials. Natural fibers show good renewability and sustainability and are hence utilized as reinforcements in polymer matrix composites. The present work concerns on the usage of Butea parviflora fiber (BP), a green material, for high end applications. The study throws light upon the characterization of raw and potassium hydroxide (KOH)-treated Butea Parviflora plant, where its physical, structural, morphological, mechanical, and thermal properties are analyzed using the powder XRD, FTIR spectroscopy, FESEM micrographs, tensile testing, Tg-DTA, Thermal conductivity, Chemical composition, and CHNS analysis. The density values of untreated and KOH-treated fibers are 1.238 g/cc and 1.340 g/cc, respectively. The crystallinity index of the treated fiber has significantly increased from 83.63% to 86.03%. The cellulose content of the treated fiber also experienced a substantial increase from 58.50% to 60.72%. Treated fibers exhibited a reduction in both hemicelluloses and wax content. Spectroscopic studies registered varying vibrations of functional groups residing on the fibers. SEM images distinguished specific changes on the raw and treated fiber surfaces. The Availability of elements Carbon, Nitrogen, and Hydrogen were analyzed using the CHNS studies. The tensile strength and modulus of treated fibers has risen to 192.97 MPa and 3.46 Gpa, respectively. Thermal conductivity (K) using Lee's disc showed a decrement in the K values of alkalized BP. The activation energy Ea lies between 55.95 and 73.15 kJ/mol. The fibers can withstand a good temperature of up to 240 °C, presenting that it can be tuned in for making sustainable composites.

Effects of Ply Orientations and Stacking Sequences on Impact Response of Pineapple Leaf Fibre (PALF)/Carbon Hybrid Laminate Composites

This study investigated the impact response behaviours of pineapple leaf fibre (PALF)/carbon hybrid laminate composites for different ply orientations and stacking sequences. The laminates were manufactured using a vacuum infusion approach with various stacking sequences and ply orientations classified as symmetric quasi-isotropic, angle-ply symmetric, and cross-ply symmetric. The laminates were analysed using an IMATEK IM10 drop weight impact tester with an increment of 5 J until the samples were perforated. This investigation reveals that the overall impact properties of PALF and carbon as reinforcements were improved by a beneficial hybridised effect. The laminates with an exterior carbon layer can withstand high impact energy levels up to 27.5 J. The laminate with different stacking sequences had a lower energy transfer rate and ruptured at higher impact energy. The laminates with ply orientations of [0°/90°] and [±45°]₈ exhibited 10% to 30% better energy absorption than those with ply orientations of [±45°₂, 0°/90°₂]_s and [0°/90°₂, ±45°₂]_s due to energy being readily transferred within the same linear ply orientation. Through visual inspection, delamination was observed to occur at the interfaces of different stacking sequences and ply orientations.

Dynamic and Ballistic Performance of Uni- and Bidirectional Pineapple Leaf Fibers (PALF)-Reinforced Epoxy Composites Functionalized with Graphene Oxide

Replacing synthetic fibers with natural ones as reinforcement in polymeric composites is an alternative to contribute to sustainability. Pineapple leaf fibers (PALF) have specific mechanical properties that allow their use as reinforcement. Further, graphene oxide (GO) has aroused interest due to its distinctive properties that allow the improvement of fiber/matrix interfacial adhesion. Thus, this work aimed to evaluate the ballistic performance and energy absorption properties of PALF-reinforced composites, presenting different conditions (i.e., GO-functionalization, and variation of fibers volume fraction and arrangement) through residual velocity and Izod impact tests. ANOVA was used to verify the variability and reliability of the results. SEM was employed to visualize the failure mechanisms. The Izod impact results revealed a significant increase in the absorbed energy with the increment of fiber volume fraction for the unidirectional configuration. The ballistic results indicated that the bidirectional arrangement was responsible for better physical integrity after the projectile impact. Furthermore, bidirectional samples containing 30 vol.% of GO non-functionalized fibers in a GO-reinforced matrix showed the best results, indicating its possible application as a second layer in multilayered armor systems.

Natural Fiber-Reinforced Thermoplastic ENR/PVC Composites as Potential Membrane Technology in Industrial Wastewater Treatment: A Review

Membrane separation processes are prevalent in industrial wastewater treatment because they are more effective than conventional methods at addressing global water issues. Consequently, the ideal membranes with high mechanical strength, thermal characteristics, flux, permeability, porosity, and solute removal capacity must be prepared to aid in the separation process for wastewater treatment. Rubber-based membranes have shown the potential for high mechanical properties in water separation processes to date. In addition, the excellent sustainable practice of natural fibers has attracted great attention from industrial players and researchers for the exploitation of polymer composite membranes to improve the balance between the environment and social and economic concerns. The incorporation of natural fiber in thermoplastic elastomer (TPE) as filler and pore former agent enhances the mechanical properties, and high separation efficiency characteristics of membrane composites are discussed. Furthermore, recent advancements in the fabrication technique of porous membranes affected the membrane's structure, and the performance of wastewater treatment applications is reviewed.

The Influence of Pineapple Leaf Fiber Orientation and Volume Fraction on Methyl Methacrylate-Based Polymer Matrix for Prosthetic Socket Application

This work reports on the use of low-cost pineapple leaf fiber (PALF) as an alternative reinforcing material to the established, commonly used material for prosthetic socket fabrication which is carbon-fiber-reinforced composite (CFRC) due to the high strength and stiffness of carbon fiber. However, the low range of loads exerted on a typical prosthetic socket (PS) in practice suggests that the use of CFRC may not be appropriate because of the high material stiffness which can be detrimental to socket-limb load transfer. Additionally, the high cost of carbon fiber avails opportunities to look for an alternative material as a reinforcement for composite PS development. PALF/Methyl Methacrylate-based (MMA) composites with 0°, 45° and 90° fiber orientations were made with 5-50 v/v fiber volume fractions. The PALF/MMA composites were subjected to a three-point flexural test to determine the effect of fiber volume fraction and fiber orientation on the flexural properties of the composite. The results showed that 40% v/v PALF/MMA composite with 0° fiber orientation recorded the highest flexural strength (50 MPa) and stiffness (1692 MPa). Considering the average load range exerted on PS, the flexural performance of the novel composite characterized in this work could be suitable for socket-limb load transfer for PS fabrication.