In this work, poly(L-lactic acid)/thermoplastic alginate (PLA/TPA) biocomposites were prepared through a melt blending method. The TPA was initially prepared using glycerol as a plasticizer. The effects of TPA content on the interactions between blend components, thermal properties, phase morphology, mechanical properties, hydrophilicity, and biodegradation properties of biocomposites were systematically investigated. Fourier transform infrared (FTIR) spectroscopy analysis corroborated the interaction between the blend components. The addition of TPA enhanced the nucleating effect for PLA, as determined by differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) revealed poor phase compatibility between the PLA and TPA phases. The thermal stability and mechanical properties of the biocomposites decreased with the addition of TPA, as demonstrated by thermogravimetric analysis (TGA) and tensile tests, respectively. The hydrophilicity and soil burial degradation rate of biocomposites increased significantly as the TPA content increased. These results indicated that PLA/TPA biocomposites degraded faster than pure PLA, making them suitable for single-use packaging, but this necessitates careful optimization of TPA content to balance mechanical properties and soil burial degradation rate for practical single-use 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 problem of chemical soil pollution after military actions on the territory of Ukraine is becoming quite urgent in terms of ecological risks. The aim of the article was to establish the level of ecological safety of soils after the application of biosorption technology and to substantiate its ecological and economic feasibility. Within the scope of the study, three scenarios were set to evaluate the level of ecological risk under the condition of actual complex contamination of soils with five heavy metals (Zn, Cu, Ni, Pb, and Cd) - Scenario 1 and in the case of biosorption technology application for soil protection - Scenarios 2 and 3. Scenarios 2 and 3 differed in the type of substrate for anaerobic digestion (chicken manure and sewage sludge, respectively) compatible with phosphogypsum to obtain a biocomposite. Innovative approach for ecological risk assessment was improved based on the Bayes' theorem and developed set of qualitative and quantitative parameters. Based on the theoretical substantiation of the complex formation indicator and the fluorescent properties of digestate organic matter, the efficiency of heavy metal immobilisation in the soil was evaluated, which contributed to the reduction of ecological risk from moderate to low level for both scenarios. The results of the risk assessment based on Bayes' theorem showed a decrease in the level of risk from high to medium. Ecological and economic efficiency was assessed according to methodology of ecological damage after hostilities. The economically effective technology developed can be recommended for the comprehensive soil restoration scheme due to the obtained results.
This work focused on the development of a hydrophobic biocomposite film reinforced with natural jute fiber. The biocomposite was made using a blend of chitosan and guar gum and reinforced with varying concentration of jute fiber followed by casting and air drying in petri dishes. Microscopic analysis of the cross-sectional structure of the films revealed a dense, compact morphology and FTIR result shows evidence of chemical interaction of the composite components. The inclusion of Jute fiber was found to increase the water repellant capacity of the films. The film water vapor permeability (WVP) was reduced from 4.1 x 10(-10) (g/m(2)center dot day center dot kPa) to 1.2 x 10(-10) (g/m(2)center dot day center dot kPa) with addition of jute fiber. Although the presence of Jute affects color properties of the films, it significantly improved their ability to block UV-Vis light. The tensile strength and elongation at break of CS/GG 0 % JT film, CS/GG/1 % JT, CS/GG/1.25 %JT and, CS/GG/1.5 % JT film was turned out to be (38.4 MPa, 45.3 MPa, 51.6 MPa and 60 MPa), (15.33 %, 17.66 %, 21.33 % and, 14 %) respectively. Notably, an increased in the DPPH radical scavenging assay was also observed from similar to 87 % in CS/GG composite to 99.4 % (1 % JT film), 99.66 % (1.25 %JT film) and 99.83 % for 1.5 % JT reinforced films respectively. Furthermore, all films showed excellent antimicrobial activity against the foodborne pathogen Escherichia coli and Fusarium oxysporum fungi highlighting their potential as active food packaging material. Signs of biodegradation were observed following four month of soil burial test, confirming the environmental sustainability of the produced biocomposite film.
Jarosite is an inorganic byproduct waste produced during the purification and refining of zinc in the industry. Recycling such waste as a filler in biocomposites could be a sustainable solution to manage it. To create jute-jarosite-soy biocomposites, varying weight percentages of jarosite are combined with soy resin and applied to woven jute cloth. The impact of jarosite on the mechanical characteristics, hardness, fire retardant, thermal stability, hydrophobicity, and degrading nature of jute-soy composites was investigated, and it was discovered that its presence by a part of 3 weight percentage enhanced tensile strength by 37.2% and flexural strength by 34.7%, respectively. The hardness and thermal stability of jute-jarosite-soy composites are enhanced by 17.5% and 35.8%, respectively, over jute-soy composites. After 60 days, soil burial analyses of these composites revealed more than 70% weight loss. Due to its moderate strength and entirely biodegradable nature, manufactured jute-jarosite-soy composite can be used to replace non-degradable thermoplastic usage in several sectors.
The increasing environmental concerns regarding plastic waste, especially in agriculture, have driven the search for sustainable alternatives. Agricultural plastics, such as mulching films and greenhouse covers, are heavily reliant on petrochemical-derived materials, which persist in the environment and contribute to long-term pollution. This study explores the use of biodegradable biocomposites made from steam explosion-treated chicken feathers and various polymer matrices to address these issues. Chicken feathers, a waste by-product of the poultry industry, present an excellent biodegradability as a result of the steam explosion treatment and contain nitrogen, potentially enhancing soil fertility. The biocomposites were characterized by thermal stability, mechanical properties, and biodegradability, and ecotoxicity assessments were carried out studying the incorporation of feathers into the soil. Results showed that the incorporation of treated chicken feathers increased the water absorption capacity of the composites, promoting faster disintegration and biodegradation. In particular, biocomposites made with polyhydroxyalkanoates and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) exhibited a significant increase in degradation rates, from 3-10% in the first month for pure matrices to 40-50% when reinforced with treated feathers. Meanwhile, those made from polylactic acid showed slower degradation. Furthermore, the addition of feathers positively influenced crop growth at low concentrations, acting as a slow-release fertilizer. However, high concentrations of feathers negatively affect plant growth due to excess nitrogen. These findings highlight the potential of poultry feathers as a valuable, sustainable filler for agricultural bioplastics, contributing to waste valorization and environmentally friendly farming practices.
Polylactic acid (PLA) and tapioca starch biocomposites offer a sustainable alternative to petroleum-based plastics for single-use packaging. This study focused on optimizing injection molding parameters for a novel PLA/tapioca starch blend using response surface methodology (RSM). Injection temperature had the most significant impact on tensile strength. The optimal parameters identified were injection temperature of 181 degrees C, pressure of 40 MPa, and speed of 300 mm/s, achieving a tensile strength of 25.34 MPa without defects. Morphological analysis revealed smoother fracture surfaces and presence of microfibrils denoting increased ductility. Mechanical properties, including 16 % elongation, 24.5 MPa flexural strength, and 9.32 kJ/m2 impact strength, were comparable to conventional plastics. Enhanced biodegradation in ambient soil conditions was observed, while migration tests showed no leaching in most stimulants, supporting its potential for sustainable packaging applications.
The accumulation of plastics in the environment is a well-recognized issue. To address this, biodegradable materials such polylactic acid (PLA) have been developed. In natural environments such as soil or water, PLA degradation progresses slowly but steadily. To accelerate the degradation of the material, this study investigates the degradation of a biocomposite material using PLA as a matrix and Pennisetum setaceum fiber as reinforcement. Disintegration and marine biodegradability tests, both at the seawater/sediment interface and in marine sediment, were conducted. Different measurement tests were employed to quantify the degradation of PLA and composite samples, focusing on the mass loss and the variation of the mechanical and thermal properties. The results consistently demonstrated greater mass loss and mechanical property deterioration during the disintegration test compared to the marine biodegradability tests. Notably, the composite material exhibits more significant degradation than the pure polymer without fiber. For composite, the addition of fiber increased the degree of biodegradability compared to the plastic matrix.
This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene-vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the addition of EVA to LDPE increased the elasticity of biocomposites. The elongation at break for filled biocomposites increased from 9% to 317% for microcrystalline cellulose and from 9% to 120% for wood flour (with an increase in the EVA content in the matrix from 0 to 50%). The biodegradability of biocomposites was assessed both in laboratory conditions and in open landfill conditions. The EVA content in the matrix also affects the rate of the biodegradation of biocomposites, with an increase in the proportion of the copolymer in the polymer matrix corresponding to increased rates of biodegradation. Biodegradation was confirmed gravimetrically by weight loss, an X-ray diffraction analysis, and the change in color of the samples after exposition in soil media. The prepared biocomposites have a high potential for implementation due to the optimal combination of consumer properties.
The extensive use of non-biodegradable and petroleum derived polymers in industry exacerbates environmental problems associated with plastic waste accumulation and fossil resource depletion. The most promising solution to overcome this issue is the replacement of these polymers with biodegradable and bio-based polymers. In this paper, novel biocomposites were prepared from bio-based polyamide 5.6 (PA56) with the addition of olive stone powder (OSP) at varying weight concentrations by melt compounding method. The degradability of the prepared biocomposites is investigated through soil burial test, and assessed by reduction in their mechanical properties. The biodegradability of bio-based polyamide 5.6 is shown to be improved by addition of olive stone powder, and its effects on the properties of polymer matrix are elucidated. The Fourier transform infrared (FTIR) spectrum of the biocomposites indicate the successful incorporation of OSP into PA56 polymer matrix. After six-month soil burial test, scanning electron microscopy and FTIR show the degradation of PA56 through morphological and structural changes, respectively. Differential scanning calorimetry reveals the changes in the transition temperatures of the polymer matrix and an increase in crystallinity. Thermogravimetric analysis is used on the biocomposite to determine the fraction of its components, polymer and biofiller, and the results show that 2.67% (w/w) of the polyamide 5.6 is biodegraded at the end of the six-month soil burial.