Search Results (241)

Lightning strikes pose a significant risk during outdoor activities. The connection between conventionally used rescue blankets in alpine emergencies and the risk of lightning injury is unclear. This experimental study investigated whether rescue blankets made of aluminum-coated polyethylene terephthalate increase the likelihood of lightning injuries. High-voltage experiments of up to 2.5 MV were conducted in a controlled laboratory setting, exposing manikins to realistic lightning discharges. In a balanced test environment, two conventionally used brands were investigated. Upward leaders frequently formed on the edges along the fold lines of the foils and were significantly longer in crumpled rescue blankets (p = 0.004). When a lightning strike occurred, the thin metallic layer evaporated at the contact point without igniting the blanket or damaging the underlying plastic film. The blankets diverted surface currents and prevented current flow to the manikins, indicating potentially protective effects. The findings of this experimental study suggest that upward leaders rise from the edge areas of rescue blankets, although there is no increased risk for a direct strike. Rescue blankets may even provide partial protection against exposure to electrical charges. Full article

The practice in agriculture of spreading polyethylene (PE) film over the soil surface as mulch is a common, global practice that aids in conserving water, increasing crop yields, suppressing weed growth, and decreasing growing time. However, these films are typically only used for a single growing season, and thus, their use and non-biodegradability come with some serious environmental consequences due to their persistence in the soil and potential for microplastic pollution, particularly when retrieval and disposal options are poor. On the microscale, particles < 5 mm from degraded films have been observed to disrupt soil structure, impede water and nutrient cycling, and affect soil organisms and plant health. On the macroscale, there are obvious and serious environmental consequences associated with the burning of plastic film and its leakage from poorly managed landfills. To maintain the crop productivity afforded by mulching with PE film while avoiding the environmental downsides, the development and use of biodegradable polymer technologies is being explored. Here, the efficacy of a newly developed, water-dispersible, sprayable, and biodegradable polyester–urethane–urea (PEUU)-based polymer was compared with two commercial PE mulches, non-degradable polyethylene (NPE) and OPE (ox-degradable polyethylene), in a greenhouse tomato growth trial. Water savings and the effects on plant growth and soil characteristics were studied. It was found that PEUU provided similar water savings to the commercial PE-based mulches, up to 30–35%, while showing no deleterious effects on plant growth. The results should be taken as preliminary indications that the sprayable, biodegradable PEUU shows promise as a replacement for PE mulch, with further studies under outside field conditions warranted to assess its cost effectiveness in improving crop yields and, importantly, its longer-term impacts on soil and terrestrial fauna. Full article

Biodegradable mulch films (BDMs) are considered a promising solution for mitigating plastic residue pollution in agroecosystems. However, the degradation behavior and ecological impacts of their residues on soil–plant systems remain unclear. Here, a pot experiment was conducted using an acidic purple soil (AS), a neutral purple soil (NS), and a calcareous purple soil (CS) to investigate the degradation of 1% (w/w) microplastics derived from polyethylene mulch film (PE-MPs) and polybutylene adipate terephthalate/polylactic acid (PBAT/PLA) mulch film (Bio-MPs), as well as their effects on soil properties, bacterial communities, and radish growth. PE-MPs degraded slightly, while the degradation of Bio-MPs followed the order of NS > CS > AS. PE-MPs and Bio-MPs enhanced the nitrification and radish growth in AS but had no significant effects on soil properties and radish growth in CS. Bio-MPs notably increased the relative abundance of PBAT/PLA degradation-related bacteria, such as Ramlibacter, Bradyrhizobium, and Microbacterium, across the three soils. In NS, Bio-MPs raised soil pH and enriched nitrogen-fixing and denitrifying bacteria, leading to a decrease in NO₃⁻-N content and radish biomass. Overall, the effects of Bio-MPs on soil–plant systems varied with soil properties, which are closely related to their degradation rates. These findings highlight the need to assess the ecological risks of BDM residues before their large-scale use in agriculture. Full article

The aim of this work was to improve the technology for obtaining coating based on plasticized polylactide from its aqueous suspensions. For this purpose, a film formation process with additional heating was developed, and the influence of plasticizers on the film-formation temperature was investigated. It is shown that using only mechanical emulsification, it is possible to obtain a material with an average particle size of 2.4 microns, which is suitable for further research and modification for film materials. The introduction of epoxidized fatty acids (oleic and linolic) was found to reduce the film-formation temperature by 20–30 °C compared to the unplasticized polymer, which puts them on par with the classical plasticizer, polyethylene glycol, reducing the film-formation temperature by 36% at the same concentration. Full article

The recycling of plastics collected from household waste to produce post-consumer recycled (PCR) materials is a critical step of sustainable waste management. However, the processing of PCR materials presents unique challenges, particularly in the context of seasonal input stream fluctuations and resulting PCR material composition variations. Within this paper, the influence of batch-to-batch fluctuations on the processing stability and product properties of high-density polyethylene (HDPE) PCR from the German municipal waste system is analysed. It examines how variations in batch composition affect key parameters such as processing data (injection pressure, torque), mechanical properties (tensile strength, E-modulus, impact strength), and product quality (gel formation, part dimensions, part weight). Therefore, six consecutive household HDPE PCR material batches are analysed regarding their composition, contaminations, and rheological characteristics through ashing, differential scanning calorimetry, high-temperature gel permeation chromatography, and high-pressure capillary rheometry. The batches are then processed using blown- and cast-film extrusion as well as injection moulding, and the resulting process stability and product quality are analysed. The results show a strong correlation between thermal properties, such as crystallisation enthalpy, molecular weight, polypropylene (PP) content, varying batch viscosities, and changes in processing data as well as the resulting product properties. Full article

Polymer residues can be reused in civil construction by partially replacing mineral aggregates in concrete, thereby reducing the extraction of natural resources. This study aimed to evaluate the use of powdered poly (ethylene terephthalate) (PET) and polyethylene (PE) residues, accumulated in shaving-mill filters during the extrusion of multilayer films used in food packaging, in the production of sealing masonry blocks. The PET/PE residues were characterized by Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Cylindrical specimens were produced in which part of the sand, by volume, was replaced with 10, 20, 30, 40 and 50% polymer residue. The cylindrical specimens were evaluated for specific mass, water absorption and axial and diametral compressive strengths. The 10% content provided the highest compressive strength. This formulation was selected for the manufacture of concrete blocks, which were evaluated and compared with the specifications of ABNT NBR 6136:2014. The concrete blocks showed potential for applications without structural function and were classified as Class C. The results, in line with previous investigations on the incorporation of plastic waste in concrete, underscore the promising application potential of this strategy. Full article

Plastic film mulching is widely used in protected agriculture. However, the residues of various types of plastic films, as a consequence, severely affect soil quality. The most widely promoted alternative strategy is the use of biodegradable plastic films. Nevertheless, the research on the effects of different types of plastic films on soil properties remains insufficient. This study explored the impacts of different plastic film mulching on the physicochemical properties and microbial communities of soils for pepper cultivation, with three treatments: traditional polyethylene film (PE-Ctr), PBAT biodegradable film (PBAT bio), and reinforced polyethylene film (RPE). The results showed that the soil pH value was the highest in PE-Ctr treatment, and the soil organic matter content was higher in the biodegradable film treatment, while the electrical conductivity (EC), nitrate, and some cations (Ca²⁺, Mg²⁺) were higher in the RPE treatment. The contents of available trace element Zn, Fe, and Mn increased in the PBAT bio treatment. The bacterial richness and evenness indices were higher in PBAT bio treatment than those of other treatments. The fungal community had a relatively high richness, but a lower evenness, compared to the PE-Ctr and PBAT bio treatments. The use of different plastic films significantly affected the composition of soil bacteria, while differences in the composition of soil fungi were only observed between the PBAT bio and RPE treatments. Proteobacteria, Acidobacteriota, and Actinobacteriota were the most dominant bacterial phyla, and Ascomycota and Mortierellomycota were the dominant fungal phylum across all treatments. FAPROTAX functional prediction showed that the abundances of multiple functions of soil bacteria were higher in the RPE treatment, and the chemoheterotrophy function was higher in the PE treatment. FUNGuild analysis indicated that the trophic types and ecological function groups of soil fungi were more abundant in the PBAT bio treatment. Full article

This study aims to improve the performance of wood–plastic composites (WPCs) composed of cotton stalk powder and residual film particles. Additionally, it aims to promote the efficient utilization of cotton stalk biochar. The composites were prepared using modified cotton stalk biochar and xylem powder as the matrix, maleic anhydride grafted high-density polyethylene (MA-HDPE) as the coupling agent, and polyethylene (PE) residual film particles as the filler. The WPCs were fabricated through melt blending using a twin-screw extruder. Mechanical properties were evaluated using a universal testing machine and texture analyzer, Shore D hardness was measured using a durometer, and microstructure was analyzed using a high-resolution digital optical microscope. A systematic investigation was conducted on the effect of biochar content on material properties. The results indicated that modified biochar significantly enhanced the mechanical and thermal properties of the WPCs. At a biochar content of 80%, the material achieved optimal performance, with a hardness of 57.625 HD, a bending strength of 463.159 MPa, and a tensile strength of 13.288 MPa. Additionally, thermal conductivity and thermal diffusivity decreased to 0.174 W/(m·K) and 0.220 mm²/s, respectively, indicating improved thermal insulation properties. This research provides a novel approach for the high-value utilization of cotton stalks and residual films, offering a potential solution to reduce agricultural waste pollution in Xinjiang and contributing to the development of low-cost and high-performance WPCs with wide-ranging applications. Full article

As an aspect of green road construction, the use of waste plastic agricultural film in asphalt pavement not only mitigates environmental pollution but also enhances the mechanical properties of asphalt. However, it has been plagued by problems such as poor low-temperature crack resistance and poor compatibility. To address this problem, this study used waste low-density polyethylene (LDPE), sourced from waste film, and the plasticizer diisononyl phthalate (DINP) to enhance the properties of asphalt. Based on orthogonal tests, rheological property tests, conventional property tests, storage stability tests, fluorescence microscopy (FM), and Fourier transform infrared (FTIR) tests, waste LDPE/plasticizer DINP-modified asphalt samples were evaluated. Orthogonal tests indicated that a modified asphalt optimum preparation process of 30 min and 4500 rpm at 180 °C was beneficial. Conventional and rheological property tests revealed that 4% waste LDPE modified with 2.5% plasticizer DINP represents the optimal combination to effectively enhance the low-temperature rheological properties of asphalt while exerting minimal impact on its high-temperature characteristics. Storage stability and FM analysis indicated that waste LDPE is evenly dispersed in the modified asphalt binder when 3% plasticizer DINP is added. FTIR analysis revealed no change in the absorption peaks after waste LDPE and plasticizer DINP were added to asphalt, indicating that no chemical reactions occurred. Overall, waste LDPE/plasticizer DINP-modified asphalt exhibits excellent rheological properties and storage stability, which are conducive to green road construction and resource utilization. Full article

Biodegradable mulch films not only provide similar field benefits to conventional mulch films but also degrade naturally, rendering them an effective alternative to traditional polyethylene mulch films for mitigating “white pollution”. However, recent studies have focused on the material selection and soil ecological impacts of biodegradable mulch films, while their effects on soil water temperature regulation and root architecture in drip-irrigated rice cultivation remain unclear. To address this research gap, in this study, various treatments including no mulch (NM), conventional plastic mulch (PM), and four types of biodegradable mulch films (BM-W₁, BM-B₁, BM-B₂, and BM-B₃) were established, and their effects on the soil hydrothermal flux, root architecture, biomass accumulation, and resource use efficiency of drip-irrigated rice were analyzed at different growth stages. The results indicated the following: (1) Compared with the NM treatment, film mulching increased the soil hydrothermal fluxes and water retention capacity, thereby promoting root growth and biomass accumulation, ultimately increasing the effective panicle number and grain yield. (2) Among the biodegradable film treatments, BM-B₃ (with a degradation period of 105 days) maintained relatively higher soil temperature for a longer duration, which increased surface root distribution in the mid-to-late growth stages, further improving fine root growth and biomass accumulation, consequently enhancing both yield and water use efficiency. In contrast, BM-B₁ and BM-B₂ exhibited excessively rapid degradation rates, leading to significant fluctuations in soil moisture and temperature, thereby negatively affecting water supply and nutrient uptake and ultimately restricting root growth and development. (3) The entropy weight (EW) technique for order of preference by similarity to ideal solution (TOPSIS) model results revealed that although the PM treatment was more advantageous in terms of soil temperature, root dry weight, and soil moisture content, BM-B₃ provided a slightly higher yield than the PM treatment did and offered the advantage of biodegradability, making it a preferred alternative to conventional mulch film. In summary, this study revealed the mechanism by which biodegradable mulch films enhanced biomass accumulation and yield formation in drip-irrigated rice production by optimizing soil hydrothermal dynamics and root architecture, thereby exploring their potential as replacements for conventional mulch films. These findings provide a theoretical basis for the efficient and sustainable production of drip-irrigated rice in arid regions. Full article

The co-pyrolysis of straw biomass and polyethylene film at different mass ratios was carried out in a small fixed-bed reactor with CaO as catalyst. The resulting synthesis gas production, liquid and solid products, and pyrolysis kinetics were studied by gas chromatography and thermogravimetric analysis. The results showed that with increasing proportion of plastic in the feedstock, co-pyrolysis had a synergistic effect on the CH₄ yield, reaching as high as 3.124 mol CH₄/kg feedstock, while the H₂ and CO yields continuously decreased. Comparing the experimental and theoretical yields of synthesis gas, the trends for CO and CH₄ were consistent, but those of H₂ and CO₂ differed widely. Examining the influence of element mass ratios in the feedstock on the synthesis gas composition, it was found that the biomass and plastics affected the formation of oxygen- and hydrogen-containing gases, respectively. The activation energy and pre-exponential factor showed increasing and decreasing trends, respectively, when the feedstock proportions and heating rate changed. Fitted linear correlation coefficients for all pyrolysis stages exceeded 0.99. Full article

Multilayer plastic films (MPFs) are widely used in the food industry. Despite its widespread use, the recycling of MPF remains a challenge due to its complex structure. Solvent-based recycling is more complex and costly than conventional mechanical recycling, which remains the most widely used method despite its technical and economic limitations. This study investigates the conventional mechanical recycling of post-consumer MPF without separating its constituent layers. Samples were prepared using a thermal extrusion cycle with the control of temperature, speed and sample size to improve the melt state, homogeneity and mechanical response of the mixture. The results of the physicomechanical characterization in this research study show that the proper selection of the extrusion parameters for a fine multilayer waste of 2 mm particle size, has a positive impact, for instance, on the final maximum strength of the recycled material, demonstrating an increase of up to 40 and 70% in tensile and flexural properties, respectively. The proposed mechanical recycling of post-consumer MPF without separation of its constituents can produce a material with mechanical properties comparable to those of low-density polyethylene and polypropylene. These findings could significantly benefit the recycling industry by reducing plastic pollution and allowing for creating new products with specific mechanical properties tailored for different applications. Full article

To address the problem of environmental pollution caused by the extensive use of low-density polyethylene (LDPE) mulch film, this study developed a novel sprayable mulch using natural fibers and biodegradable polymers. Urea–formaldehyde resin (UF), strengthened with polyvinyl alcohol (PVA), was used as a modifier to induce beneficial physicochemical structural changes in PVA-modified urea–formaldehyde (PUF) resins. Characterization of these resins was conducted using Fourier transformation infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Preparation of the biodegradable mulch was conducted using Xuan paper waste residue (XP) as an enhancer, with PUF as the auxiliary agent. The resulting film (PUF-XP) was examined for differences in thickness, morphological characterization, and rate of weight loss, and the effects of different covering films on cucumber growth, root development, soil temperature, and weed control were evaluated. Characterization reveals that when the PVA content was 4% (W4UF), the film had the lowest free formaldehyde content (0.26%) and highest elongation at break (5.70%). In addition, W4UF could easily undergo thermal degradation at 278.4 °C and possessed a close-knit, three-dimensional structural network. W4UF was then mixed with paper powder and water in various proportions to produce three mulch films (BioT1, BioT2, and BioT3) that demonstrated excellent water retention and heat preservation and inhibited weed growth by 68.8–96.8%. Compared to no mulching (NM), BioT1 increased both the specific root length and root density, as well as improved the plant height, stem diameter, and total biomass of the cucumbers by 43.5%, 34.1%, and 33.9%, respectively. Therefore, a mass ratio of paper powder, water, and W4UF of 1:30:2 produced a biodegradable mulch film that could be used as an alternative to LDPE, mitigating the environmental pollution rendered by synthetic plastic mulch films and offering the potential for a sustainable agricultural application. Full article

The dependence of polyethylene deformation on applied mechanical stress under varying load conditions and radiation doses was investigated experimentally. Obtained results reveal significant alterations in the mechanical properties of polyethylene following irradiation with krypton ions at doses of 1.5 × 10⁶, 1.6 × 10⁷, 5.0 × 10⁸, and 1.0 × 10⁹ ions/s. The stress–strain curves obtained for both the unirradiated and irradiated samples are numerically modeled using frameworks developed by the authors. The findings indicate that irradiation with krypton ions at an energy level of 147 MeV exerts a pronounced impact on the deformation and strength characteristics of polyethylene. Notably, increasing the radiation dose to 10⁹ particles/s results in a 2.5-fold increase in the rate of mechanical stress. Furthermore, the degree of deformation distortions in molecular chains induced by high-energy Kr¹⁵⁺ ion irradiation has been quantified as a function of irradiation fluence. Increasing the irradiation fluence from 10⁶ ion/cm² to 10⁷ ion/cm² causes only minor variations in deformation distortions, which are attributed to the localized isolation of latent tracks and associated changes in electron density. A comparative analysis of the mechanical behavior of irradiated polymer materials further revealed differences between ion and electron irradiation effects. It was observed that Teflon films lose their plasticity after irradiation, whereas polyethylene films exhibit enhanced elongation and tearing performance at higher strain values relative to their non-irradiated counterparts. This behavior was consistently observed for films irradiated with both ions and electrons. However, an important distinction was identified: high-energy electron irradiation degrades the strength of polyethylene, whereas krypton ion irradiation at 147 MeV does not result in strength reduction. Full article

This study addresses the challenges of efficient, large-scale production of flexible transparent conducting electrodes (TCEs). We fabricate TCEs on polyethylene terephthalate (PET) substrates using a high-speed roll-to-roll (R2R) compatible method that combines gravure printing and photonic curing. The hybrid TCEs consist of Ag metal bus lines (Ag MBLs) coated with silver nanowires (AgNWs) and indium zinc oxide (IZO) layers. All materials are solutions deposited at speeds exceeding 10 m/min using gravure printing. We conduct a systematic study to optimize coating parameters and tune solvent composition to achieve a uniform AgNW network. The entire stack undergoes photonic curing, a low-energy annealing method that can be completed at high speeds and will not damage the plastic substrates. The resulting hybrid TCEs exhibit a transmittance of 92% averaged from 400 nm to 1100 nm and a sheet resistance of 11 Ω/sq. Mechanical durability is tested by bending the hybrid TCEs to a strain of 1% for 2000 cycles. The results show a minimal increase (<5%) in resistance. The high-throughput potential is established by showing that each hybrid TCE fabrication step can be completed at 30 m/min. We further fabricate methylammonium lead iodide solar cells to demonstrate the practical use of these TCEs, achieving an average power conversion efficiency (PCE) of 13%. The high-performance hybrid TCEs produced using R2R-compatible processes show potential as a viable choice for replacing vacuum-deposited indium tin oxide films on PET. Full article