Hybrid jute–water hyacinth fiber reinforced polyester composites: valorizing natural waste towards sustainable materials

The construction industry has become the focal point of sustainability as one of the largest con- sumers of natural resources and waste producers. A sustainable construction industry is possible with the sustainability of building materials, which is the main factor controlling the construc- tion management process. In this research, the importance levels of a total of 17 criteria under the headings of economic, environmental, and social sustainability in terms of sustainability of building materials and the importance levels of 11 obstacles to the use of sustainable materials were investigated through a survey conducted with the participation of 60 people. Whether there were differences between the participants’ opinions was investigated through inferential analysis. In ranking criteria according to their importance level, the health of workers and cit- izens, safety in construction and operation, and toxic emissions took the first three places. The risks of higher initial cost, total cost, and extra time are the biggest obstacles to using sustainable materials. In addition, the obstacles were subjected to factor analysis, and a model consisting of four factors was created. The study revealed the criteria for sustainable material selection and the barriers to sustainable material use in a holistic manner. In this respect, it is evaluated that it will be a guide for governments, local governments, building material manufacturers, designers, contractors, and ultimately users to achieve a more sustainable construction sector.

This study explores the possibility of using sustainable materials in the form of natural fibers for reinforcing and improving the subgrade strength of pavements. Natural fibers with suitable biochemical properties were used for subgrade reinforcement in the past. Recently, the use of a waste weed, water hyacinth (WH), has garnered popularity as it can reinforce soil with the added advantage of waste utilization. It is well known that natural fibers have limited life when used in soils due to their degradation with time. For improving the longevity of the fiber and enhancing the mechanical performance of the soil-fiber composite, an effort was made in this study to chemically coat the natural fiber surface with nanoparticles of ferric hydroxide. The chemical coating can alter the short-term, as well as long-term, mechanical and chemical characteristics of WH fiber-impregnated soil, which is not well understood. The primary objective of the current study focuses on the short-term behavior of ferric hydroxide-coated WH fiber-impregnated soil that can be used as pavement subgrade. The effect of the chemical coating on WH fibers was initially analyzed by field emission scanning electron microscopy and energy dispersive X-ray tests. The impregnation of nanoparticle on the fiber surface increases surface roughness, coats the porous lumen of the fiber, and increases the tensile strength of the material. A set of tensile strength and moisture absorption tests was done for both untreated and treated WH fiber. The fiber tensile strength of treated fiber (TF) increased by 1.25 times as compared to untreated fiber (UF). The moisture absorption of TF decreased significantly from 580 % for UF to 255 %, indicating that the modified fiber became more hydrophobic. Unconfined compressive strength and direct shear tests were performed to evaluate the improvement in mechanical characteristics of chemically altered randomly distributed fiber-reinforced soil. The increase in cohesion, friction angle, and compressive strength at various compaction states has been discussed for soil reinforced with treated fibers (TF + S), untreated fibers (UF + S), and unreinforced soil (BS). For demonstrating the subgrade performance, soaked and unsoaked California bearing ratio tests were conducted on fiber-reinforced soil. For all the tests conducted on soil combinations (BS, (UF + S), and (TF + S)), the TF-reinforced soil composite performed the best. The results demonstrate the efficacy of using chemically altered natural fiber in increasing the subgrade strength of pavements.

This research investigates the effect of fiber pre-treatment on the mechanical and physical properties of unidirectional water hyacinth (WH) fiber reinforced epoxy resin composites. The water hyacinth fibers have been produced by mechanical processing. The 50–70 cm length of WH stems are brushed with an iron brush to mechanically extract the strands. The dry fibers then were pre-treated by alkalization and esterification. The alkalization ha ve been conducted by immersing the WH fibers on 2 %, 5 % and 10 % NaOH solution for 24 h. The esterification of WH fibers have been done using acetate anhydride. The composite with 15 %, 25 % and 35 % of unidirectional WH fibers was made by hand lay-up. After hand lay up process the WH composites then compacting with pressure compaction 5 MPa. Tensile test and was done based on ASTM D3039. The density of composites was tested based on Archimedes rule. Surface contaminants have been eliminated by fiber treatment. The NaOH treatment eliminated the surface's wax and cuticle. The surface of fibers treated with 10 % NaOH was cleaner than those treated with 5 % NaOH. Fiber treatment has the effect of reducing fiber thickness.The tensile test results of the composite reinforced with WH fiber with NaOH treated and acetate anhydride show that the tensile strength of untreated WH fiber reinforced epoxy resin composites increased with the increase of % WH fiber. The tensile strength results that acetate anhydride treatment of WH fiber reinforced epoxy resin composites showed increased WH fiber increase the tensile strength of composite. The highest tensile strength of epoxy resin reinforced with WH fiber with acetate anhydride treatment

This study investigates the potential use of natural fibers derived from Astragalus gummifer (AG) as reinforcement in flame‐retardant polyester (FRP) composites. With rising demand for sustainable, eco‐friendly, and biodegradable materials, AG fibers offer a promising alternative, characterized by low density, thermal resistance, and lightness. Composites were fabricated using the hand lay‐up compression molding method, with FRP matrices incorporating AG fibers at 55%–75% volume fractions. The specimens were evaluated for density, porosity, water absorption, ultrasonic pulse velocity (UPV), compressive strength, thermal conductivity, acoustic absorption, and dynamic properties. The results showed that increasing fiber content reduced density and UPV, while porosity, water absorption, and compressive strength increased. Thermal conductivity ranged from 0.0656 to 0.1062 W/m·K, with porosity improving insulation performance. Acoustic tests revealed that specimens with lower resin content and higher porosity achieved excellent sound absorption at medium and high frequencies (SAC = 0.88 at 1600 Hz; SAC = 0.94 at 6300 Hz). Dynamic analysis indicated higher natural frequencies but lower damping capacity, confirming the trade‐off between stiffness and damping. These findings demonstrate that AG fiber‐reinforced composites are lightweight, sustainable materials with strong thermal and acoustic properties. Potential applications include energy‐efficient building insulation, as well as the automotive, aerospace, and defense industries where weight reduction and multifunctionality are required. However, high water absorption and weak fiber–matrix bonding, confirmed by SEM analysis, may limit long‐term durability, particularly in humid environments. Future research should focus on chemical modification, interfacial optimization, and aging tests to improve performance and broaden the applicability of these bio‐based composites.

The aim of the research work reported in this article is to fabricate water hyacinth fiber reinforced polyester composites and characterize its mechanical properties. The fiber material was extracted manually after collecting the water hyacinth plant from Lake Koka in the Oromia Region, Ethiopia. Once the extraction was done, the fiber was treated by a chemical in different sodium hydroxide concentration, used for the improvement of bond and interfacial strength of the water hyacinth fiber. The composite of water hyacinth fiber is fabricated with polyester resin, using hand lay-up methods in different fiber/matrix ratios. The mechanical properties of the specimens were then measured according to ASTM standard recommendations experimental tests such as tensile, flexural and compressive tests were conducted on the prepared composite material samples. The results show that 20% fiber content is around optimum content for best mechanical behavior and all the mechanical properties are satisfactorily improved when the water hyacinth polyester composite is chemically treated using NaOH. Therefore, using water hyacinth fibers as reinforcement in a polymer matrix, it has been proved that successful composites can be developed.KeywordsNatural fiberWater hyacinth fiberPolyester resinHand lay-up fabricationMechanical property

Composites of water hyacinth fiber thermoset epoxy (WHE) composites were developed and characterized. Water hyacinth (WH) fibers were treated in an optimized 6% concentration of sodium hydroxide (NaOH) solution for an hour before composite fabrication by mixing with an epoxy resin (E) matrix. Fourier Transform Infrared (FTIR) and Field Emission Scanning Electron Microscopy (FE-SEM) analyses were conducted on both the treated water hyacinth (TWH) and untreated water hyacinth (WH) fibers, and the constituent composites. The mechanical properties (such as tensile, flexural, and impact) of the WHE composites were tested. The results obtained showed that treated water hyacinth epoxy composites (TWHE) provided better mechanical properties with remarkable improvement of up to 13%, 17%, and 7% for tensile, flexural, and impact strength, respectively, in comparison with untreated water hyacinth epoxy composites (WHE). FESEM results revealed strong fiber/matrix interfacial bonding between the treated fibers and epoxy matrix while the untreated WHE composites showed evidence of poor compatibility between the untreated WH fibers and the epoxy matrix, thus decreasing the mechanical properties of the composites. The results have demonstrated that water hyacinth fibers have the potential as an alternative material to replace synthetic fibers in composite applications.

The isolation and characterization of nanocrystalline cellulose (NCC) from water hyacinth (WH) fibers were carried out. There are two treatments to obtain NCC from WH fibers by chemical and mechanical treatments. The chemical treatment involved alkalization with NaOH 25% in a highly-pressured tube, acid hydrolysis with 5M HCl, and bleaching with (NaClO2:CH3COOH) in ratio 5:2. The mechanical treatment was performed by using ultrasonic homogenizing at 12000 Rpm for 2 h. The morphological surface was observed by Transmission Electron Microscopy (TEM). TEM reported that the size of NCC was 10–40 nm. Crystallinity index and functional group analysis of the NCC WH fibers were also examined using X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. XRD reported that the crystallinity index increased significantly after chemical and mechanical treatment due to the presents of crystalline area in the WH fibers. The crystallinity index of raw fiber, digester, bleaching, and ultrasonic homogenizing were 7%, 68%, 69%, and 73% respectively. The content cellulose of final product was 68% as measured by the chemical composition test. Meanwhile, FTIR reported that WH fibers after being given chemical treatment lead the functional group change due to removal hemicellulose and lignin. The result of XRD and FTIR were indicated that the sample of NCC WH fibers presents the structure of cellulose crystal type I.

Characteristic of local water hyacinth (WH) fibers and composites that consist of mixing WH fibers and unsaturated polyester (UPR) were studied. Composites mixed with the WH fibers treated in different alkali concentration for 1 h soaking time were tested by tensile and flexure machine and their fracture surface was observed by using scanning electron microscope (SEM). The results show that 7% NaOH, 1 h, treated WH fibers provided better mechanical properties on UPR matrix composites in comparison with other alkali concentrations. From SEM observation, some untreated WH fibers pulled out from their matrix were observed clearly in fracture surface of composites. The high alkali concentration created damage of cellulosic structure, thus decreasing of mechanical properties of the composites.

Mechanical properties of water hyacinth fibers – polyester composites before and after immersion in water

Asphalt sand layer (Latasir) is a layer of road construction consisting of coarse aggregates, fine aggregates, fillers and hard asphalt, which are mixed, spread, and compacted in hot conditions at certain temperatures. In this study is the use of water hyacinth fiber in a mixture of thin layer sand sheet sand grade grade A. The purpose of this study was to determine the process of making test specimens with ingredients added to water hyacinth fiber and the process of testing specimens with ingredients added to water hyacinth fiber. The test was carried out by adding water hyacinth fibers in the sand sheet class A latasir mixture. And with the addition of water hyacinth fiber variations of 0.6%, 0.9%, 1.2% taken from asphalt content. The final result of this research was Marshall evaluation which was obtained for the effect of the addition of water hyacinth cellulose fiber in this study showed an increase in Marshall stability value of 27.29% with a mixture of 1.2% water hyacinth, plastic fatigue (Flow) decreased by -23 , 89% with a mixture of 0.9% water hyacinth, cavity filled in the mixture (Void in the Mix) increased by 18.65% with a mixture of 1.2% water hyacinth, cavity filled with asphalt (Void Filled With Asphalt) decreased by -8.74% with a mixture of 1.2% water hyacinth, cavity in aggregate (Void In Mineral Aggregate) increased by 7.80% with a mixture of 1.2% water hyacinth, and Marshall Quotient increased by 71.78% with a mixture of 0.9% water hyacinth. These results indicate that water hyacinth fiber can be used as an ingredient to add a mixture of latasir sand sheet class A specifications of clan development. Keywords: sand sheet class A sandflies, Marshall Test Index, water hyacinth fiber, stability, flow, Marshall Quotient.

This paper focusses on the analysis of thermo-mechanical and morphological properties of water hyacinth (WH) fiber reinforced polypropylene (PP) biocomposites manufactured by using a single screw extruder and an injection molding machine. With a view to increasing the compatibility between the WH fibers and polypropylene matrix, raw WH fibers were chemically treated with Benzenediazonium salt in base media. Composites were manufactured with five different levels of loading (15, 20, 25, 30 and 35 wt%) of both the raw and treated WH fibers. Thermal properties of WH-PP composites were evaluated by thermogravimetric and differential thermal analyses. To analyze mechanical properties of composites, tests of tensile strength and stiffness, flexural strength and stiffness, and Charpy impact strength were carried out following ASTM standards. It was found that thermal stability and all the mechanical properties except tensile strength were improved considerably for chemically treated WH fiber composites in comparison with untreated ones. Fracture surfaces of the tensile and flexural specimens were scanned with scanning electron microscopy (SEM) to understand their surface morphologies. The SEM images clearly revealed that there were fewer fiber agglomerations, microvoids, and fiber pull out traces in treated WH-PP composites than in the untreated ones indicating better distribution of the fibers into the matrix as well as stronger fiber matrix interfacial adhesion due to treatment of WH fibers. Water absorption properties were studied to evaluate the viability of these biocomposites under specified conditions.

Mycelium-based composites are a promising avenue for innovating sustainable materials from the hyphae of fungi. This study focuses on the use of fibers from four local fungal species, namely, Pleurotus ostreatus, Pleurotus sajor-caju (Fr. Singer), Auricularia auricula-judae, and Schizophyllum commune Fr., to produce mycelium-based composites from water hyacinth. An inoculum of each of the mushroom species was cultivated on PDA medium at 25 and 30 °C to determine the optimal temperature based on the growth rate. The obtained optimal condition was used to grow the fungi on water hyacinth (WH) mixed with rice bran in different proportions (100% WH, 70% WH, and 50% WH) with various numbers of fungal inocula (10, 20, and 30 plugs). The obtained composites were coated with a solution of either starch, chitosan, or epoxy resin. Schizophyllum commune Fr. exhibited the highest growth rate and fiber density, with a growth rate of 1.45 ± 1.92 mm/day at 30 °C. Ten inocula of Schizophyllum commune Fr. incubated at 30 °C for seven days on a mixture of 50% WH and 50% rice bran gave the optimal composite. Coating the obtained composite with chitosan improved its mechanical properties, but coating it with epoxy resin improved its water absorbency. Buried in soil, the composite coated with a chitosan solution decomposed within 30 days. The results indicate that Schizophyllum commune Fr. can be used as a binder to produce mycelial composites on a substrate of WH mixed with rice bran. The implications of these results will enable the further development and tuning of mushroom-based materials, especially for the production of sustainable bio-construction materials derived from local mushrooms and bio-waste.

The microbial cells can store energy in the form of polyhydroxyalkanoates (PHAs) while the nutrient sources are exhausted but have an excess of carbon sources. Poly(3-hydroxybutyrate) (PHB) was known as one of the most common PHA. Currently, PHB is assessed as a potential alternative to petroleum-based plastics such as HDPE, PP. In addition, PHB can be obtained from different microbes through the fermentation of renewable and sustainable materials such as waste from food or cassava starch industry, and other agricultural by-products. Although the spread of water hyacinth (Eichhornia crassipes) is becoming a problem in many provinces, it still is considered an opulent biomass source. Besides the application in the removal of heavy metals from wastewater, or making animal feed and fertilizer, water hyacinth can be converted into a carbon source used in microbial fermentation. This paper indicates the PHA synthesis ability of 28 bacterial strains which were isolated from soybean-growing soil samples and the Cau Dien Waste-treatment Plant’s mud samples. Based on their PHA accumulation capability while using C5 and C6 sugars as carbon sources, Bacillus sp. AI 10 and Bacillus sp. CRCXL 2.2 were chosen to synthesize PHA using the water hyacinth hydrolysate as a carbon source. Pretreated water hyacinth biomass using Ca(OH)2 was subjected to enzymatic hydrolysis with a suitable ratio of Cellic→CTec2 and Cellic→HTec2, which resulted in a 409.5 mg total reducing sugars/g pretreated biomass. After 48 hours of fermentation, the dry biomass and accumulated PHA amount from Bacillus sp. AI 10 and Bacillus sp. CRCXL 2.2 were 4.79 g/L, 51.2% and 3.84 g/L, 34.7%, respectively. The Fourier transform infrared spectroscopy (FTIR) spectra of both strains’ PHA structure showed that they can accumulate the homopolymer of PHB. From these results, it is possible to produce PHB by microorganisms from water hyacinth biomass, and participate in the circular bio-economic chain.

Evaluation of single and tri-element adsorption of Pb2+, Ni2+ and Zn2+ ions in aqueous solution on modified water hyacinth (Eichhornia crassipes) fibers

This study explores the enhancement of mechanical, thermal, and tribological properties of Ricinus communis stem fiber (RCSF)-reinforced polyester composites by incorporating biosilica derived from Proso millet husk as a filler. The RCSF fibers were treated with 5 wt% NaOH to improve the fiber-matrix bonding. Biosilica was added at varying concentrations (1–5 vol%) into the polyester matrix. The tensile strength increased from 42.6 MPa to 61.5 MPa with 4% biosilica, and the flexural strength improved from 72.15 MPa to 93.65 MPa at the same filler content. The 4% biosilica sample also showed the highest impact strength at 80.71 kJ/m2. Thermal analysis indicated improved stability, with a significant increase in weight retention at higher temperatures, especially for composites with higher biosilica content. In tribological tests, the optimal biosilica content (3–4%) reduced the specific wear rate (SWR) to 1.56 × 10−5 mm3 /Nm and the coefficient of friction (COF) to 0.239. However, higher concentrations of biosilica led to agglomeration, reducing composite performance. The study highlights the potential of biosilica-reinforced RCSF composites as a sustainable material, providing a balance of mechanical strength, thermal stability, and wear resistance for engineering applications.