Search Results (13)

Recycled polypropylene (rPP) biocomposites represent a convergent strategy for plastic waste valorization and agro-industrial residue reutilization. This study quantifies tensile, flexural, and compressive performance (ASTM D638, D790, D695) of rPP biocomposites incorporating raw corn stover (Zea mays), banana pseudostem (Musa spp.), and barley residue (Hordeum vulgare) fibers at 10, 20, and 30 wt%, processed by single-screw extrusion and compression molding without compatibilizer. Two-way ANOVA with Tukey HSD post hoc analysis (α = 0.05) evaluated effects of fiber type and concentration. Tensile strength declined monotonically across all systems, from 24.9 MPa (neat rPP) to 7.9 MPa at 30 wt% banana fiber. Corn fiber exhibited exceptional tensile concentration stability (only −11% across the full range) and the best flexural retention at 10 wt% (36.6 MPa, 79% of neat rPP). A performance plateau was identified at 20 wt% under both tensile and flexural loading, beyond which further addition produced no significant reduction. Under compression, fiber type exerted its largest statistical effect (F = 81.231), all three systems were mutually distinguishable, and no plateau was observed. These results establish a loading-mode-resolved mechanical baseline for uncompatibilized rPP biocomposites, with corn fiber at 10–20 wt% as the most versatile formulation across all loading modes. Full article

The pavement surface temperatures in Iraq are remarkably high, causing the asphalt to deteriorate quickly, shortening its service life. While a large amount of corn husk, an agricultural waste, is available for use as an asphalt modifier, researchers have not yet fully investigated this option. In this study, the use of corn husk fiber powder (CHFP) as a long-term modifier for asphalt binders and mixtures that are exposed to high-temperature conditions is evaluated. CHFP was mixed into a 40–50 penetration grade asphalt binder at concentrations ranging from 0.0% to 0.6% by weight. Performance was assessed using laboratory tests such as penetration, softening point, rotating viscosity, dynamic shear rheometer (DSR), aging (RTFOT and PAV), and wheel tracking. The findings revealed that CHFP greatly lowers penetration while increasing the softening point, indicating increased stiffness and high-temperature stability. Rheological research showed an increase in the rutting parameter (G*/sinδ) and viscosity, as well as reduced temperature susceptibility. At the mixed level, CHFP reduced rut depth while improving dynamic stability, indicating increased resistance to permanent deformation. The best performance was obtained at 0.3% CHFP, after which, improvements decreased due to probable dispersion constraints. The performance improvement is related to the creation of a reinforcing fiber network and the absorption of light asphalt components. Overall, CHFP is a promising, environmentally friendly and cost-effective addition for increasing asphalt pavement performance and promoting sustainable waste management. Full article

This study explores the possibility of making cardboard and molded egg carton packaging from corn residues and common reed as alternatives to wood-based pulp. Six formulations were made: corn husks (CHs), corn leaves (CLs), corn leaves (35%) plus corn husks (30%) and a corn blend (15%) of wollastonite (CaSiO₃) (CH + CL + W), a corn blend (CH + CL: husks 60%, leaves 40%), mixed corn waste (MCW) and shredded common reed (SR). Optical microscopy was used to evaluate the fiber morphology, including the calculation of the flexibility coefficient, the cell wall rigidity and the Runkel ratio, for raw materials and fiber after alkaline hydrolysis and casting of egg cartons in silicone molds. The grammage, burst strength and index, folding endurance, thickness and moisture content were measured in the cardboard samples, while warping, compressive deformation, moisture and ink absorption were measured in the egg cartons. The flexibility coefficient of the common reed fibers (64.5%) was better than that of the corn fibers (23.6%), and so was the Runkel ratio (0.86 vs. 1.2). In the case of cardboard formulations, the maximum burst strength (462.4 kPa) and the maximum burst index (3.0 kPa·g/m²) values were obtained with the MCW formulation, and the highest folding endurance (42 and 38 double folds) was obtained with the CH and SR formulations, respectively. The addition of wollastonite improved folding endurance to 28 double folds and reduced moisture content to 4.1%, whereas the moisture content was reduced but burst strength decreased to 250.5 kPa. Egg cartons made from corn were found to satisfy all the requirements tested for good packaging, while the reed-based cartons were found to have inadequate ink absorbency time (20 min), making them less printable. Overall, mixed corn residues seem to be the most promising raw materials for sustainable packaging, and wollastonite can be used to adjust the flexibility–strength balance. Full article

Driven by global environmental regulations that strictly limit copper content in brake pads, traditional copper-based friction materials face significant challenges due to their negative ecological impacts. Consequently, the development of sustainable, copper-free alternatives has become an inevitable trend in the braking industry. This study proposes a novel approach to developing high-performance green friction materials by utilizing a synergistic combination of agricultural wastes, specifically corn cobs, wheat straw, rice husks, and sugarcane bagasse, and carbon fibers. Research indicates that the friction coefficient of the synergistic formulation remains stable within the range of 0.35 to 0.48. Compared with the control group, this formulation achieves an average reduction in the wear rate of 19.28% and an increase in the recovery rate of 5.15%, demonstrating superior tribological performance. The synergistic interfacial regulation between carbon fibers and agricultural waste facilitates the construction of a smooth and stable friction layer, which maintains consistent performance during extended operating conditions. Among all formulations investigated, the composite reinforced by the synergy of corncob and carbon fiber exhibits the most prominent comprehensive properties, with the wear rate decreasing by 28.73% and the recovery performance improving by 4.05% relative to the specimen containing copper fibers. This work not only provides a new pathway for the sustainable development of green friction materials but also offers a theoretical basis for the high-value utilization of agricultural waste resources. Full article

This study focuses on the machinability optimization of bio-waste corn husk fiber–reinforced epoxy composites during drilling, with the objective of minimizing delamination and improving hole quality required for mechanical fastening applications. While natural fiber composites have been widely investigated, systematic statistical optimization of drilling parameters for corn husk fiber composites remains limited. The novelty of this work lies in identifying the dominant drilling parameter and establishing a clear damage-control strategy using a Taguchi L16 design coupled with ANOVA. Drilling experiments were conducted by varying spindle speed (1000, 1500, 2000, and 2500 rpm), drill diameter (6, 8, 10, and 12 mm), feed rate (00.05, 0.10, 0.15, and 0.20 mm/rev), and point angle (90°, 100°, 110°, and 120°). The results show that the drill diameter is the governing factor affecting delamination, contributing 73.52% of the total variation, followed by spindle speed (22.68%), whereas feed rate (3.14%) and point angle (0.38%) have minimal influence. The optimal condition (2500 rpm, 6 mm drill diameter, and 0.05 mm/rev feed rate) produced the lowest delamination and improved surface integrity. Microscopic observations confirmed reduced fiber pull-out and matrix cracking under these conditions. The main advantage of the proposed approach is the clear identification of parameter priority, enabling the industry to control drilling damage by primarily selecting appropriate drill diameter and spindle speed. The findings provide practical machining guidelines for the use of corn husk fiber composites in lightweight panels, automotive interior parts, and secondary structural components where reliable bolted joints are required. Full article

Corn processing generates substantial volumes of agricultural by-products, collectively referred to as corn stover, comprising husks, cobs, stalks, leaves, and silks. Although rich in bioactive compounds, these by-products are still predominantly destined for low-value uses such as landfilling and open-field burning. They contain valuable biomolecules such as lignocellulosic fibers, starch, pectin, proteins, and polyphenols, all of which hold significant potential for applications in agricultural and food industries. These compounds offer opportunities as sustainable alternatives to conventional ingredients and as novel functional additives. However, utilization of corn stover remains focused on biofuel production, limiting the development of applications in broader, high-value fields such as functional food ingredients. This review aims to highlight the opportunities that corn stover presents for developing solutions for food production, which is becoming increasingly important as the global population continues to grow and food demand rises, particularly in regions where access to sufficient and nutritious food remains limited. It also considers the challenges to be solved in order to incorporate corn stover in circular economies, like the impact of pesticide presence on derived products and gaps of emerging strategies for scaling up production in alignment with circular economy goals and the high-value utilization of corn stover. Full article

This study investigates the environmental issue of air pollution (PM 2.5) from agricultural waste in Thailand and promotes the utilization of agricultural wastes by using their chemical compositions, especially cellulose content. The fourth readily available varieties of agricultural waste, such as rice straw, corn husk, hemp shive, and durian rind, were selected to evaluate their fiber morphology and chemical properties. Subsequently, dialdehyde carboxymethyl cellulose (DCMC) was produced from four kinds of agricultural wastes under synthesis conditions involving a pH value of 3.0, a reaction temperature of 35 °C, a mass ratio of NaIO₄ and carboxymethyl cellulose (CMC) of 1:3, and a reaction time of 4 h. The formation of aldehyde substitution was confirmed by the degree of oxidation (DO) and aldehyde content. To characterize the DCMC properties determined, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), gel permeation chromatography (GPC), and scanning electron microscopy (SEM) were used. The results revealed that rice straw, corn husk, hemp shives, and durian rinds presented high DO and aldehyde content; the aldehyde contents were more significant than 30% and 50%, respectively. The highest DO and aldehyde contents were 38.63 and 77.23%, respectively, for the hemp shives. The characterized data in recent research illustrated that the added value of agricultural wastes could be increased by DCMC production, which can be applied as a crosslinking reagent for future novel biopolymer film applications. Full article

Corn husk, a by-product of corn starch production and processing, contains high-quality dietary fiber (DF). Our study compares and analyzes the impact of Hericium erinaceus solid-state fermentation (SSF) on the structure and physicochemical characteristics of soluble dietary fiber (SDF) of corn husks. The study also investigates the kinetics of SSF of H. erinaceus in this process. The scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) results revealed significant structural changes in corn husk SDF before and after fermentation, with a significant elevation in the functional group numbers. The data indicate that the fermented corn husk SDF’s water-holding, swelling, and oil-holding capacities increased to 1.57, 1.95, and 1.80 times those of the pre-fermentation SDF, respectively. Additionally, the results suggest that changes in extracellular enzyme activity and nutrient composition during SSF of H. erinaceus are closely associated with the mycelium growth stage, with a mutual promotion or inhibition relationship between the two. Our study offers a foundation for corn husk SDF fermentation and is relevant to the bioconversion of maize processing by-products. Full article

Natural fiber reinforcements have the potential to enhance mechanical properties, thereby improving performance and durability in various applications. In this study, we comprehensively evaluated the impact of environmental degradation over 120 days on reprocessed polypropylene (PP) reinforced with corn husk fiber (CHF) composites. The manufactured systems underwent rigorous analysis using various techniques, including Fourier transform infrared spectroscopy, thermogravimetric analysis, optical microscopy, scanning electron microscopy, and tensile testing. These analyses revealed that climatic conditions significantly influenced (p < 0.05) the mechanical properties of all systems. Photodegradation led to surface morphological changes and chemical structures. Regardless, adding CHF filler proved a key factor, as it allowed for less susceptibility to environmental degradation than the reprocessed matrix. These findings, therefore, provide robust evidence supporting the feasibility of using CHF composites for manufacturing agricultural containers. Full article

Noise pollution is often overlooked and invisible, but it significantly impacts the quality of human life. One of the most straightforward solutions to mitigate noise pollution is by using sound-absorbing materials. Recently, research trends to develop sound absorbing green materials, typically derived from agricultural by-products, have witnessed an uptick. This paper summarizes the sound-absorbing properties of various green materials found in the literature, including coconut fiber, kenaf fiber, rice bran, rice husk, rice straw, Hanji (a traditional Korean paper), tea-leaf fiber, mandarin peel, pineapple-leaf fiber, corn husk, peanut shell, sugar palm trunk, Yucca gloriosa fiber, fruit stones, wood barks, flax fiber, and nettle fiber. Natural fibers can be made by compressing the raw material or manufacturing them into fibrous materials or composites. The key variables that determine sound absorption performance are the thickness and density of the green material, as well as the presence of an air back cavity. Generally, thicker materials exhibit better sound absorption performance in the low- and mid-frequency range. Moreover, higher density is associated with better sound absorption performance at the same thickness. Additionally, increasing the distance between the sound-absorbing material and the air back cavity enhances sound absorption performance at low frequencies. Thus, these physical variables, rather than the specific materials used, primarily influence sound absorption capabilities. Therefore, various green materials, such as fibers, granules, and porous materials, can be effective sound absorbers if their thickness, density, and air back cavity are properly controlled. Full article

In this work, the effects of different fiber loadings on the mechanical properties of the composites at the sub-micron scale were studied through nanoindentation followed by physical characterization. The composites were prepared by incorporating different loadings of wheat straw, corn stalk, and rice husk in polypropylene copolymer using a melt processing method followed by thermal–hydraulic compression technique. Nanoindentation experiments in quasi-continuous stiffness mode were performed on the surfaces of produced composites to study the composites’ elastic modulus, hardness, and creep properties. The obtained results expressed the in-depth study of the micro- and macro-level structure and behavior of particle interactions. The findings demonstrated that observable shifts in composites’ hardness, elastic modulus, and creep rate had occurred. The WS-reinforced biocomposite sheet showed the highest elastic modulus of 1.09 and hardness of 0.11 GPa at 40 wt% loading in comparison to other loadings. An impact strength of 7.55 kJ/m² was noted for the biocomposite at 40 wt% RH loading. In addition, optical microscopy, Fourier transform infrared spectroscopy, water absorption, thickness swelling, and Vicat softening point studies were conducted on biocomposite sheets to evaluate differences in physical, mechanical, and thermal properties. The outstanding mechanical performance of the newly developed composites makes them suitable for use as a biodegradable packaging material. Full article

Research Highlights: For the first time, a model was developed and applied for polysaccharide production from Trametes versicolor grown in agro-industrial and woody residues under solid-state fermentation (SSF) conditions. Background and Objectives: Fungal biomass is an important biological resource for biotechnological applications. Basidiomycetes fungi can be grown and developed on lignocellulosic materials such as forestry, wood, and agro-industrial residues in order to produce value-added products like bioactive polysaccharides. The objectives of this study were to evaluate the effects of the C/N ratio and copper concentration on biomass and polysaccharide production during solid state fermentation (SSF), as well as on the consumption of cellulose and hemicellulose, and lignin degradation, and to propose and validate a mathematical model to describe the overall SSF process. Materials and Methods: This research was carried out by growing three Basidiomycetes species (T. versicolor, Lentinula edodes, and Pleurotus ostreatus) on twelve formulations of solid substrates using mixtures of different inexpensive lignocellulosic residues such as oak sawdust, coconut fiber (hairs), coffee husks, and corn bran plus soybean oil, calcium carbonate, and two levels of copper(II) sulfate. Results: The three fungal species grew well on all substrate formulations. The statistical analysis of experimental data showed no significant effects on polysaccharide production, in the range of C/N and copper concentrations evaluated. Taking into account that the best polysaccharide production was obtained with T. versicolor (96.09 mg/g solid substrate), a mathematical model was proposed for this fungus to describe the behavior of the fermentation system from the obtained data of all the resulting combinations to reach the highest polysaccharide production by the fungus. Conclusions: The mathematical model disclosed in this work enabled to describe the growth and development of a higher basidiomycete under solid-state fermentation conditions on lignocellulosic substrates as well as the production of value-added products like polysaccharides with medicinal properties. Full article

Interest in nanocellulose obtained from natural resources has grown, mainly due to the characteristics that these materials provide when incorporated in biodegradable films as an alternative for the improvement of the properties of nanocomposites. The main purpose of this work was to investigate the effect of the incorporation of nanocellulose obtained from different fibers (corncob, corn husk, coconut shell, and wheat bran) into the chitosan/glycerol films. The nanocellulose were obtained through acid hydrolysis. The properties of the different nanobiocomposites were comparatively evaluated, including their barrier and mechanical properties. The nanocrystals obtained for coconut shell (CS), corn husk (CH), and corncob (CC) presented a length/diameter ratio of 40.18, 40.86, and 32.19, respectively. Wheat bran (WB) was not considered an interesting source of nanocrystals, which may be justified due to the low percentage of cellulose. Significant differences were observed in the properties of the films studied. The water activity varied from 0.601 (WB Film) to 0.658 (CH Film) and the moisture content from 15.13 (CS Film) to 20.86 (WB Film). The highest values for tensile strength were presented for CC (11.43 MPa) and CS (11.38 MPa) films, and this propriety was significantly increased by nanocellulose addition. The results showed that the source of the nanocrystal determined the properties of the chitosan/glycerol films. Full article