This study investigates the mechanical, thermal, and wears characteristics of eco-friendly composite materials (designated as N1 to N5) with varying ratios of silicon nitride (biogenic Si3N4) and biochar along with jute and kenaf microfiber. The primary aim of this research study was to investigate the suitability of low cost biomass derived functional ceramic fillers in composite material instead of high cost industrial ceramics. Both the bio carbon and biogenic Si(3)N(4 )were synthesized from waste sorghum husk ash via pyrolysis and thermo-chemical method. Further the composites are prepared via mixed casting process and post cured at 100 degrees C for 5 h. According to results, the mechanical properties show a consistent improvement, attributed to the contributions of biogenic Si3N4. Moreover, the specific wear rate decreases progressively, with a larger biogenic Si(3)N(4 )and bio carbon filler %. The presence of biochar acts as solid lubricant and offered balanced friction coefficient. The composite N4 attained maximum mechanical properties including tensile (110 MPa), flexural (173 MPa), impact (6.1 J), hardness (82 shore-D), compressive (138 MPa) and lap shear strength (16 MPa). On contrary, the composite N5 attained least thermal conductivity of 0.235 W/mK, Sp. Wear rate of 0.00545 with COF of 0.26. Similarly, the scanning electron microscope (SEM) analysis revealed highly adhered nature of fillers with matrix, indicating their cohesive nature indicating the strong interfacial adhesion between the fillers and the matrix, attributed to the presence of biochar, which enhances mechanical interlocking and provides functional groups that promote chemical bonding with the polymer matrix, leading to improved load transfer efficiency and overall composite performance. Moreover, thermal conductivity values exhibit a marginal decline with the presence of biogenic Si(3)N(4)and biochar. Overall, the study demonstrated that biomass-derived functional fillers are capable candidates for providing the required toughness and abrasion-free surfaces, as evidenced by the increased impact strength, improved wear resistance, and enhanced durability observed in treated specimens compared to the control samples.This approach offers both economic and environmental benefits by reducing human exposure to hazardous pollutants through the utilization of biomass-derived materials, which help divert waste from landfills, lower air pollution caused by burning conventional plastics, and minimize soil contamination from non-biodegradable waste. In addition, the developed natural fiber-reinforced composites exhibited competitive mechanical performance compared to conventional industrial ceramic-reinforced composites, demonstrating comparable strength, enhanced toughness, and improved damping properties while offering the advantages of lower density, biodegradability, and cost-effectiveness. These findings highlight the potential of biomass-derived fillers as sustainable alternatives in structural applications.
Corn silk (CS), an agricultural byproduct obtained after the processing of corn, is usually dumped as waste. Worldwide there is a growing concern to utilise this waste for making value-added products. This work tried to improve the functional properties of corn silk fibres and utilise them to fabricate biocomposites for automotive applications. Raw corn silk fibres were alkali treated (2%, 45 min) to achieve around 11% improvement in tensile strength, 14% improvement in elongation-at-break and 26% reduction in initial modulus. The alkali-treated fibres were further processed to prepare bi-directional carded webs which were ultimately reinforced in PLA matrix utilising compression-moulding technology. The biocomposites developed with different mass fractions (10% to 50%) of alkali-treated corn silk fibres were evaluated for their functional properties. The biocomposite, formulated with 40% mass fractions of treated corn silk fibre and poly(lactic) acid, exhibited the highest mechanical performance-tensile strength (74.57 MPa), Young's modulus (4.28 GPa), Flexural strength (442.45 MPa), breaking elongation (2.04%) and impact strength (3.2 kJ/m2). The biocomposites were also found to be thermally stable with no significant weight loss till 319 degrees C and 98.49% final weight loss at the end of 780 degrees C. Those biocomposites exhibited biodegradability with 2.73% weight loss and 13.11% strength loss in 30 days of burial in soil. The biocomposite reinforced with 40% alkali-treated corn silk fibres demonstrated high potential for automotive namely door panels, exterior under-floor panels, instrument panels, internal engine covers, packaging trays, seat backs, etc. Moreover, this study advances sustainable biocomposites by enhancing CS fibre properties, achieving superior mechanical strength, thermal stability, and biodegradability for automotive applications.
The impact of the field conditions on needle-punched mulches made of cellulose fibres and PLA biopolymer during the 300 days of exposure was investigated. The study observed the degradation of nonwoven mulches during specific exposure periods (30, 90, 180 and 300 days), evaluating their mechanical, morphological and chemical properties. The impact of nonwoven mulches on soil temperature and moisture, consequently on the number of microorganisms developed beneath mulches after 300 days of exposure, were analysed and associated with obtained results complementing comprehension of nonwoven mulch degradation. The findings show that nonwoven mulches made from jute, hemp, viscose and PLA fibres change when exposed to environmental conditions (soil, sunlight, rainfall, snow, ice accumulation, air and soil temperatures, wind). The changes include alterations in colour, structure shifts and modifications in properties. The results highlight the degradation pathways of cellulose and PLA mulches, revealing that cellulose-based fibres degrade through the removal of amorphous components, leading to increased crystallinity and eventual structural breakdown. WAXD findings demonstrated that microbial and environmental factors initially enhance crystalline regions in cellulose fibres but ultimately reduce tensile strength and flexibility due to amorphous phase loss. FTIR analysis confirmed the molecular changes in cellulose chains, particularly in pectin and lignin, while SEM provided direct evidence of surface damage and fibre disintegration. Furthermore, it was found that fibre types of nonwoven mulch influence soil moisture retention and soil microbial activity due to a complex interplay of fibre composition, environmental conditions and nonwoven fabric characteristics. Comprehensive mechanical, morphological and chemical results of different types of nonwoven mulch during the 300 days of exposure to the field conditions provide valuable insights into sustainable practices for using nonwoven mulches for growing crops.
In this research, the effect of using alpha fibres on the physico-mechanical properties of compressed earth bricks (CEBs) was investigated. CEBs were produced using soil, lime and different amounts (0%, 0.5%, 1%, 1.5% and 2%) of raw (RAF) or treated alpha fibres (TAF). First, the diameter, density and water absorption of RAF and TAF were determined. Then, the produced CEBs reinforced by these fibres were subjected to compressive strength, thermal test, density and capillarity water absorption tests. The obtained results showed that the addition of RAF and TAF leads to a reduction of the thermal conductivity by 33% and 31%, respectively. The finding also indicated that the density was decreased by 26% and 17% with the inclusion of TAF and RAF respectively. Besides, the compressive strength was reduced and water absorption coefficient was increased when fibres reinforced CEBs but remaining within the standard's recommended limits. Moreover, the addition of fibre improves the acoustic properties of samples by 98%. The CEBs developed in this paper could be an alternative to other more common building materials, which would lead to a reduction of energy demand and environmental problems.
Biocomposite sheets were created by blending taro pulp with rice straw, pineapple fibre, guar gum, and corn starch. The optimal composition, comprising 90 % taro pulp and 10 % corn starch, demonstrated impressive mechanical properties, including a tensile strength of 61.42 MPa, bursting strength of 13.19 kg/cm2, a contact angle of 63.4 degrees, and water uptake of 82.33 %. To understand whether these qualities can be improved by coating with chitosan, silk fibroin, or combinations of both, coated samples were also studied. Chitosan coating displayed a tensile strength of 26.79 MPa, while fibroin coating further reduced it to 15.87 MPa. Notably, a 50:50 chitosanfibroin blend increased the contact angle to 117.8 degrees, reducing water uptake to 49.67 % and water vapor transmission rate to 4.73 %, compared to 46.15 % and 3.96 % for pure fibroin coating. Analysis revealed similar spectra among coatings, indicating analogous functional groups. XRD showed a crystalline cellulose I structure with crystallinity indices of 71.96-74.18 %. DSC displayed transitions near 190-240 degrees C, while TGA showed two- stage degradation with T5 at 130-180 degrees C, T10 at 244-264 degrees C, and T50 at 325-336 degrees C. SEM confirmed surface modifications induced by coatings. Combinations with higher fibroin content exhibited reduced water uptake and water vapor transmission rates compared to pure chitosan due to differences in chemical composition. While chitosan enhanced tensile strength, fibroin had a mitigating effect. Although not fully biodegradable, the coated sheets showed varying degrees of biodegradability under soil burial conditions for 60 days. These findings highlight the tunable properties of biocomposite sheets through composition and coatings, promising for packaging applications.
Soil reinforcement remains a vital task of a geotechnical engineer. There are a few support strategies for counting sands considered in this field that are strengthened by combined hydraulic binder (such as cement) and/or fibres. The behaviour of such mixtures (sand-cement and sand-cement-fibre mixtures) in terms of direct shear response has been subject to a lot of controversy in the literature. The base material used in the framework of this study is Chlef sand (taken from Chlef Valley, Algeria), mixed with cement and reinforced with synthetic fibres and considering the use of a direct shear device. , mixed with cement and reinforced with synthetic fibres. The types of fibres in terms of the materials used in the manufacture as well as their length and physical characteristics can improve the stress/strain response of sands. Laboratory results show that the shear strength response of sand-cement mixture increases the shear strength of this last and that it was observed with the addition of cement to the sand. The tests done on the mixtures of sand and cement and on fibre-reinforced mixtures showed better strength compared with just sand or cemented sand alone. Adding fibre to the mixture improved the soil's ability to withstand shear forces. As the threshold value, the fibre content should be at least 0.15% in order to make a noticeable improvement in the mechanical properties. This increase in shear strength is noticed accompanied by a limitation in the samples' contractiveness.
Soil-cement is gaining acceptance in the construction industry for use in the improvement of sandy soil, despite its low strength Research has attempted to increase the strength of this material by increasing the percentage of additives. The current study investigated the effect of steel fibre (SF) as a reinforcer on the performance, UCS and TS at different fibre contents, lengths, diameters and shapes. The results showed that the use of 2% straight fibre significantly increased the UCS and that the samples performed better than those containing hooked or crimped. A decrease in the SF length from 10 to 5 mm and increase in the diameter from 0.3 to 0.6 mm caused decreases in the UCS. The greatest increase in TS occurred with the addition of 2% hooked fibres and was 4.6 times the increase in strength without fibres. The reason for the increase in the strength of the samples was bridge-like performance of the SFs in the soil-cement. The use of SFs together with cement to improve sandy soil is a new and effective way of improving the mechanical behaviour of the soil. This indicates that the addition of SFs can be a step towards more optimal use of soil-cement in engineering projects.
The interest in natural fibres in non - textile applications has increased as a result of the search for new renewable materials. Especially attractive for environmental safety demands are biodegradable and renewable fibres such as lignocellulose fibres and biopolymers such as PLA. The analysis of their biodegradation is often taken as a standard measure for environmentally friendly textile materials. Therefore, the aim of this paper is to investigate the biodegradation properties of Jute and PLA fibres by soil burial test. The fibres were exposed to the farmland soil for 11 days. The efficiency of the biodegradability was determined by comparison of mass loss, mechanical properties (finesses and tenacity) and morphological analysis by SEM microscope. With the purpose of a better understanding of biodegradation, the number of total fungi and bacteria in the soil is also determined.
Hemp (Cannabis sativa L.) is a versatile crop that produces cellulosic bast fibres used in textiles and biocomposites. Is also finds use in phytoremediation, being a good candidate for the cultivation on marginal lands, such as those contaminated by heavy metals (HMs). HMs like cadmium (Cd) and zinc (Zn) are known to affect plant growth and impair the biosynthesis of cellulose and lignin at the cell wall level. Since cellulose is the major component in the gelatinous layer of bast fibres, HMs can impact the structure of hemp fibres and, consequently, their mechanical properties. This study investigates how varying concentrations of Cd and Zn in the soil affect the bast fibres of hemp plantlets. The chosen model is the hypocotyl, as it is ideal for studying bast fibre development: it exhibits a temporal separation between the elongation and thickening phases within a short period of approximately three weeks. C. sativa plantlets were grown for 20 days, and the hypocotyls sampled to perform histochemical observations, gene expression analysis, as well as to quantify biomass yield and Cd/Zn accumulation. Hemp plantlets grown in soils with the three highest Zn concentrations were smaller than the control group, whereas no decrease in size was observed under elevated Cd concentrations. However, at the highest Cd concentration, the root system exhibited enhanced development, accompanied by a significant increase in dry weight across all the concentrations tested. The quantification of Cd and Zn showed that the roots were the main organs accumulating HMs. Cd at the two highest concentrations decreased significantly the lumen area of bast fibres and increased their cell wall thickness. Zn decreased significantly the lumen area, but it did not impact the thickness of the cell wall at the highest concentration. Cd also increased the number of secondary fibres. Immunohistochemistry highlighted a different pattern of crystalline cellulose distribution with a signal that was less homogeneous in the presence of Cd and Zn. Gene expression analysis revealed changes in transcripts encoding cellulose synthases, fasciclin-like arabinogalactan proteins, class III peroxidases. The results obtained shed light on the molecular response and bast fibre histological changes occurring in young hemp plants exposed to Cd and Zn.
The growing amount of plastic waste has significantly worsened environmental pollution, a problem made worse by population growth and non-sustainable manufacturing and consumption practices. This growing concern emphasises the need of developing materials that lessen traditional plastics' harmful impact on the environment. An effective substitute is offered by bioplastics, which are made from natural plant biomass such as lignin, starch, cellulose, and hemicellulose as well as bacterial polyester polymers. There is uncertainty over their actual environmental benefits as a consequence of the challenges associated with their identification, categorisation, and disposal. This study provides a thorough analysis of the biodegradation properties of bioplastics, highlighting how well they function in diverse environmental conditions. Our findings suggest that the pace at which bioplastics decompose varies significantly depending on the kind of material used as well as specific environmental factors like moisture level and microbial activity. These discoveries are crucial for developing waste management strategies and streamlining the production of bioplastics in order to increase sustainability. Subsequent endeavours have to prioritise the improvement of these bioplastics to ensure consistent biodegradation effectiveness and raising public awareness to promote their proper disposal, therefore magnifying their advantageous impacts on reducing plastic pollution.