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This research study evaluates the impact of low-density polyethylene (LDPE) modified asphalt binder on the mechanical performance and economical feasibility of asphalt concrete (AC) mixtures. LDPE-modified mixtures were compared with conventional mixes prepared with various binders commonly used in India, i.e., VG 30, VG 40, Polymer-Modified Binder (PMB), and Crumb Rubber Modified Binder (CRMB). LDPE-modified mixtures exhibit superior mechanical performance, increasing the stiffness of AC mixtures by 171% and 125% at 25 °C and 35 °C, respectively, compared to VG 30 base binder. Additionally, the indirect tensile strength (ITS) improved by 51% over VG 30. LDPE-modified mixtures also showed improved resistance to permanent deformation, with RTIndex values up to 133.46% higher than VG 30, and higher fatigue resistance, as indicated by increased CTIndex values compared to VG 30 and CRMB. However, the CTIndex values for LDPE-modified mixtures were 26.32% and 56% lower than those for VG 40 and PMB, respectively. Pavement analysis using 3D-Move showed lesser deflections at pavement layer interfaces, resulting in higher rutting and fatigue life for LDPE-modified pavements. Furthermore, LDPE-modified pavements showed up to 57% higher fatigue life (Nf) and up to 42.33% higher rutting life (Nr) than other pavements. The economic analysis showed that the cost of LDPE-modified pavements is comparable to VG 40 and around 10% more economical than pavements containing PMB. Using LDPE also offers environmental benefits by repurposing up to 750 kg for every kilometer of single-lane pavement section having 50mm thick surface course. Overall, LDPE-modified asphalt mixtures present a sustainable and high-performance solution for asphalt pavement construction. [ABSTRACT FROM AUTHOR]

The widespread use of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) plastics has resulted in a large amount of waste plastic that requires appropriate disposal or reuse. One potential solution is to use them in the modification of asphalt concrete (AC) mixtures for more sustainable highways. To study this possibility, permanent deformation and dynamic modulus (DM) of the LDPE and HDPE modified AC mixtures was investigated by conducting flow number (FN), flow time (FT) and DM tests on Superpave gyratory compacted specimens. Machine learning models; multi-layer perceptron (MLP), radial basis function neural network (RBFNN), generalized regression neural network (GRNN) and support vector machine (SVM) were used to predict the DM on the basis of frequency and temperature parameters. The model's performance was gauged by analyzing the root mean square error, mean relative error, and coefficient of determination. The study findings revealed that the LDPE and HDPE modified AC mixtures provide 2.07 times and 1.27 times better resistance to permanent deformation, respectively, than their counterpart. It was also found that the LDPE and HDPE modified AC mixtures have 2.1 times and 1.4 times higher DM values, respectively, than the Control AC mixtures. Among the machine learning models, MLP (R2 = 0.98) showed best accuracy in predicting DM and thus is recommended to be used in similar studies due to its robustness. Additionally, the feature importance analysis revealed that frequency has the highest impact on DM predictions, followed by temperature and the inclusion of the LDPE. [ABSTRACT FROM AUTHOR]

In this article, the relationship between the properties of different membranes (agar, chitosan, and agar + chitosan) and biodegradability in natural and sterilized soil was investigated. The membranes under investigation exhibited variations in the biodegradation process, a phenomenon closely linked to both the soil microbiota composition and their water affinity. Higher solubility in water and greater swelling tendencies correlated with shorter initiation times for the biodegradation process in soil. Overall, all tested membranes began biodegradation within 14 days, as assessed through thickness and morphological analysis parameters, demonstrating a superior degradation rate compared to low-density polyethylene films. [ABSTRACT FROM AUTHOR]

Low-density polyethylene (LDPE) is among the most abundant synthetic plastics in the world, contributing significantly to the plastic waste accumulation problem. A variety of microorganisms, such as Cupriavidus necator H16, Pseudomonas putida LS46, and Pseudomonas chlororaphis PA2361, can form biofilms on the surface of LDPE polymers and cause damage to the exterior structure. However, the damage is not extensive and complete degradation has not been achieved. The changes in polymer structure were analyzed using Time-domain Nuclear Magnetic Resonance (TD-NMR), High-Temperature Size-Exclusion Chromatography (HT-SEC), Differential Scanning Calorimetry (DSC), and Gas Chromatography with a Flame Ionization Detector (GC-FID). Limited degradation of the LDPE powder was seen in the first 30 days of incubation with the bacteria. Degradation can be seen in the LDPE weight loss percentage, LDPE degradation products in the supernatant, and the decrease in the percentage of amorphous regions (from >47% to 40%). The changes in weight-average molar mass (Mw), number-average molar mass (Mn), and the dispersity ratio (Đ) indicate that the low-molar mass fractions of the LDPE were preferentially degraded. The results here confirmed that LDPE degradation is heavily dependent on the presence of amorphous content and that only the amorphous content was degraded via bacterial enzymatic action. [ABSTRACT FROM AUTHOR]

This paper presents research aimed at laboratory experiments on static and cyclic fatigue testing of low-density polyethylene (LDPE) recovered from post-consumer waste in order to develop a recycled product exhibiting satisfactory mechanical and thermo-mechanical properties. The results of the cyclic fatigue tests set up to 80% of the maximum load in static tensile testing demonstrated satisfactory functionality of the recycled material developed by using the injection molding process. There was no significant change in the tensile strength under static and cyclic fatigue tests. Under cyclic loading, there was a quasi-static effect manifested by plastic deformation, and the displacement increased significantly. The static and cyclic tensile tests indicated improvement in the mechanical performance of the recycled LDPE as compared to the virgin material, owing to the high quality of the regranulates. Fourier Transform Infrared Spectroscopy (FTIR) was conducted to analyze the functional groups in virgin and recycled LDPE samples. The analysis showed no significant change in the transmittance spectra. The thermal degradation performance was also analyzed by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). The results were quite similar for both virgin and recycled LDPE. [ABSTRACT FROM AUTHOR]

Hazardous chemicals are transported on rail and road networks. In the case of accidental spillage or terror attack, civilian and military first responders must approach the scene equipped with appropriate personal protective equipment. The plausible manufacturing of chemical protective polymer material, from photocatalyst anatase titanium dioxide (TiO2) doped low-density polyethylene (LDPE), for cost-effective durable lightweight protective garments against toxic chemicals such as 2-chloroethyl ethyl sulphide (CEES) was investigated. The photocatalytic effects on the physico-chemical properties, before and after ultraviolet (UV) light exposure were evaluated. TiO2 (0, 5, 10, 15% wt) doped LDPE films were extruded and characterized by SEM-EDX, TEM, tensile tester, DSC-TGA and permeation studies before and after exposure to UV light, respectively. Results revealed that tensile strength and thermal analysis showed an increasing shift, whilst CEES permeation times responded oppositely with a significant decrease from 127 min to 84 min due to the degradation of the polymer matrix for neat LDPE, before and after UV exposure. The TiO2-doped films showed an increasing shift in results obtained for physical properties as the doping concentration increased, before and after UV exposure. Relating to chemical properties, the trend was the inverse of the physical properties. The 15% TiO2-doped film showed improved permeation times only when the photocatalytic TiO2 was activated. However, 5% TiO2-doped film exceptionally maintained better permeation times before and after UV exposure demonstrating better resistance against CEES permeation. [ABSTRACT FROM AUTHOR]

Thermoplastic fiberglass was compression molded in the form of thick panels with a nominal thickness of 10 mm and a size of 300 × 300 mm2. A simplified procedure was adopted to speed up the lamination procedure and adapt it to the aim of recycling waste, glass fibers, fabrics, and thermoplastic films. Low density polyethylene was used as a matrix to simplify the laboratory process, but the same procedure can be extended to other thermoplastic film, such as polyamide. The final thermoplastic composite shows unique properties in terms of its repairability, and its performance was improved by increasing the number of repairing repetitions. For this aim, a repairability test was designed in the bending configuration, and three consecutive cycles of bending/repairing/bending were carried out. The static mechanical properties of the final thermoplastic composite were, conversely, low in comparison with traditional fiberglass because of the choice of a polyethylene matrix. The bending tests showed that the maximum strength was lower than 10 MPa and the elastic modulus was less than 1 GPa. Nevertheless, the toughness of the thermoplastic composite was high, and the samples continued to deform under bending without splitting into two halves. [ABSTRACT FROM AUTHOR]

Enhancing the degradability of polyethylene plastics could provide a potential solution to the overwhelming crisis of plastic waste. Conventional studies have focused on the degradation of polyethylene thin films. This study investigated UV-induced photo-degradation according to ASTM D5208-14 in polyethylene sheets with thicknesses ranging from 0.4 to 1.2 mm. The impacts of sample thickness, metal pro-oxidants, polyethylene resin types and foaming were explored through the characterization of the carbonyl index, molecular weight, tensile properties and crystallinity. As pro-oxidants, single iron or manganese stearate demonstrated a concentration-dependent trend in accelerating the photo-degradation of polyethylene sheets. The thickness, foaming and resin type—such as low-density polyethylene (LDPE) and high-density polyethylene (HDPE)—significantly impacted the rate of photo-oxidation. Thick polyethylene sheets (1.2 mm) exhibited a heterogenous and depth-dependent degradation profile. As the photo-degradation progressed, the enhanced crystallinity, reduced UV transmittance and formation of crosslinks were able to prevent further oxidative cleavage of the polyethylene chain. This study investigated the time course and factors affecting the photo-degradation of polyethylene sheets, which could provide insights into the formulation design of photo-degradable polyethylene plastics. [ABSTRACT FROM AUTHOR]

This study analyzed the possibility of using plant-originated waste materials (black and green tea dust) as functional polyethylene fillers. The dependence between the size of the filler particles and their antioxidant potential is discussed. Six fractions were selected: below 50 µm, 50–100 µm, 100–200 µm, 200–400 µm, 400–630 µm and 630–800 µm. Significant differences between the effect of particle size and the antioxidant properties of black and green tea were found using the extraction method to analyze antioxidant activity (DPPH method) and total phenolic content (Folin-Ciocalteu method), suggesting a higher potential for using green tea as a filler with antioxidant properties, as well as the benefits of finer active filler distribution. Biomass waste fillers were mixed with low-density polyethylene LDPE SEB 853 I'm Green®, Braskem. Those samples were oxidized at 100 °C for 5 and 15 days to investigate the radical scavenging properties of fillers in composites. Fourier transform infrared spectroscopic studies show that the addition of both types of filler prevents the thermo-oxidation of polyethylene for 5 days. After 15 days, all samples except the BTW 400–630 and 630–800 µm exhibited oxidation. The mechanical properties of the LDPE and its' composites were tested, and we noted an increased brittleness of neat LDPE after thermal oxidation. The addition of black tea particles above 100 µm in size prevents this behavior. [ABSTRACT FROM AUTHOR]

Care for human well-being and health requires the consumption of healthy foods, and therefore, the “babyleaf” gains increased space in the market as they have higher concentrations of bioactive compounds. The present study aimed to evaluate the growth and bioactive compounds of baby-leaf chicory (Cichorium intybus L.) according to the color of cultivation benches with different wavelengths. The experiment was conducted in a non-acclimatized greenhouse, covered with low density polyethylene film with an aluminized screen of 50% shading under the film and 50% shading screens on the sides. In a completely randomized design, five types of benches were evaluated without and with bright reflective colored materials: Control bench without reflective material, a bench with reflective bright white laminate, reflective bright dark red laminate, reflective bright dark blue laminate, and reflective bright yellow laminate. The bright white and yellow laminates amplified the most photosynthetically active radiation. All the laminates enhanced yield of baby-leaf chicory plants, where white, yellow, red, and dark blue enhanced the fresh matter by 102.6%, 50.2%, 60.6%, and 37.4% compared to the control, respectively. The bright dark blue laminates enhanced the bioactive compounds of baby-leaf chicory plants. The bright dark blue laminate enhanced the carotenoid production of baby-leaf chicory plants by 11.0%. The use of colored laminates was effective in the cultivation of baby-leaf chicory, both in terms of yield and quality, with significant increases in fresh matter and bioactive compounds. To provide baby-leaf chicory with higher bioactive content with antioxidant effect (carotenoids) the use of dark blue laminates is necessary; however, if the objective is greater shoot DM it will be white laminates [ABSTRACT FROM AUTHOR]

In this work, natural fibers extracted from the medicinal aromatic plant Deverra tortuosa, with different sizes (S1 = 2 mm and S2 = 500 μm), were incorporated into recycled low density polyethylene (rLDPE) to produce sustainable biocomposites. Compounding was performed with different fiber concentrations (0 to 30% wt.) via twin-screw extrusion followed by injection molding. Based on the samples obtained, a comprehensive series of characterization was conducted, encompassing morphological and mechanical (flexural, tensile, hardness, and impact) properties. Additionally, thermal properties were assessed via differential scanning calorimetry (DSC), while Fourier transform infrared spectroscopy (FTIR) was used to elucidate potential chemical interactions and changes with processing. Across the range of conditions investigated, substantial improvements were observed in the rLDPE properties, in particular for the tensile modulus (23% for S1 and 104% for S2), flexural modulus (47% for S1 and 61% for S2), and flexural strength (31% for S1 and 65% for S2). Nevertheless, the tensile strength decreased (15% for S1 and 46% for S2) due to poor fiber–matrix interfacial adhesion. These preliminary results can be used for further development in sustainable packaging materials. [ABSTRACT FROM AUTHOR]

Reintroducing recycled plastics into production processes can lead to irreversible degradation and changes in their properties, thereby limiting their recycling potential to a finite number of loops. This study investigates the impact of process-induced degradation resulting from multiple reprocessing cycles on specific material properties and aims to establish structure–property relationships. Four different polyolefins, including two polypropylenes, high-density polyethylene, and low-density polyethylene, were selected for the study. The materials underwent extrusion, pelletizing, injection molding, and milling before being reintroduced into the reprocessing cycle. This sequence of processing steps was repeated six times on each material. Various characterization techniques, including high-temperature gel permeation chromatography, melt mass flow rate, parallel-plate rheology, differential scanning calorimetry, gas chromatography–mass spectrometry, and optical defect control system, were performed to evaluate the molecular structure, rheological behavior, thermal stability, and the resulting contaminants and defects after each reprocessing step. The reprocessing of polypropylene resulted in a gradual decrease in the average molecular weights accompanied by a shift to lower viscosities and higher melt mass flow rates, whereas the polyethylene grades showed the opposite trend with a less pronounced effect in high-density polyethylene. The volatile organic compounds rose in polypropylene and sank in polyethylene after reprocessing. Additionally, all four materials exhibited an increase in degradation-related defects based on optical defect analysis. [ABSTRACT FROM AUTHOR]

In this study, a critical evaluation and the benefits of using a waste and a virgin polymer in an asphalt mixture are presented. The present paper is the result of a three-year research effort to find a suitable recyclate compatible with asphalt binder and setting reaction conditions in the preparation of asphalt mixtures with the mentioned recyclate. This suitable candidate was recycled low-density polyethylene (LDPE), which was produced by recycling old, worn-out bags and films. An amount of 6% of LDPE by the weight of the binder content was suggested as the best amount of the modifier. Physical tests, including penetration, softening point, and kinematic viscosity have been carried out to prove the effectiveness of the modification on the binder properties. The effectiveness of the blending process and the appropriate concentration of additives led to a homogeneous polymer-modified bitumen without any imperfections in the structure. After successful preparation under laboratory conditions, this paper describes the preparation of asphalt mixtures directly in an asphalt-mixing plant and the subsequent implementation of a verification section. The overall composition of prepared polymer-modified asphalt mixtures has been studied. An important result of this study is the preparation of the asphalt mixture with waste LDPE that meets all the technical requirements. Moreover, it has been proven that this type of waste PE is fully applicable in asphalt-mixing plants in Slovakia, with zero or minimal financial burden on construction companies to complete the construction of their production facilities. Using such a technology, we can reduce the amount of waste plastics that otherwise end up in landfill. [ABSTRACT FROM AUTHOR]

This experimental study evaluated the performance of modified asphalt mixtures prepared by incorporating 2%, 4%, and 6% linear low-density polyethylene (LLDPE) by weight of asphalt binder through a series of tests. The microstructural analyses using scanning electron microscopy (SEM) were conducted on asphalt samples to assess the engineering properties of the asphalt mixes. Finally, ANOVA statistical analysis has been employed to determine the statistical significance of the differences in all tests' means. Based on laboratory findings, the Marshall stability test result showed that the modified asphalt mixes up to 4% LLDPE had enhanced performance by 12.7% compared to the control mix. A significant decrease (up to 31.3%) in binder penetration was demonstrated due to the incorporation of LLDPE into the asphalt mix. The softening point of the LLDPE–asphalt mixes was increased by up to 17.6%. It was also demonstrated that the incorporation of such LLDPE dosages maintains the flow limits within the specified range; however, the flow of the asphalt mix with 4% LLDPE was 3.17 mm which is the nearest to the average value of the upper and lower acceptable limits. The air voids of mixes with LLDPE content more than 4% by was decreased to less than 4% which is not recommended in high-temperature climates to control mixture bleeding. Microscopic analysis revealed an improvement in the densification of asphalt microstructures, attributed to the LLDPE particles significantly changing the rheology and viscosity of the base mixture and making the hot asphalt mixture more homogeneous. Based on the physical and rheological properties investigated in this study, it could be concluded that 4% LLDPE produces the best performance in asphalt mixtures. Overall, the ANOVA analysis demonstrated that the incorporation of LLDPE into asphalt mixes has a significant impact on all of their properties. [ABSTRACT FROM AUTHOR]

Low-density polyethylene (LDPE) has been widely used in various applications due to its flexibility, lightness, and low production cost. However, its massive use in disposable products has raised environmental concerns, prompting the search for more sustainable alternatives. This study aims to investigate the mechanical properties achievable in a composite material utilizing low-density polyethylene (LDPE), potato starch (PS), and cellulose microfibrils (MFCA) at loadings of 0.05%, 0.15%, and 0.30%. Initially, the cellulose acetate microfibrils (MFCA) were produced via an electrospinning process. Subsequently, a dispersive mixture of the aforementioned materials was created through the extrusion and pelletizing process to form pellets. These pellets were then molded by injection molding to produce test specimens in accordance with ASTM D 638, the standard for tensile strength testing. The evaluation of the properties was conducted through mechanical tensile tests (ASTM D638), hardness tests (ASTM D 2240), melt flow index (ASTM D1238), and scanning electron microscopy (SEM). This study determined the influence of cellulose acetate microfibril loadings below 0.3% as reinforcement within a thermoplastic LDPE matrix. It was demonstrated that these microfibrils, due to their length-to-diameter ratio, contribute to an enhancement in the mechanical properties. [ABSTRACT FROM AUTHOR]

As an abundant commodity, coffee production generates significant scraps and by-products, increasing the potential pollution hazards. Circular economy and bioeconomy can help valorize Spent Coffee Grounds (SCGs), e.g., as fillers in polymer-based composites using conventional manufacturing, i.e., injection molding. Large-format additive manufacturing with pellet extruders offers a further option for new applications, reducing costs for the valorization of biomass waste. However, its use in this context remains unexplored, especially for applications with complex geometries or critical overhangs. This work investigates new biomass waste-based materials for large-format additive manufacturing with direct feeding extrusion, fabricating self-supported complex overhang geometries through nonplanar slicing. The thermal, rheological, and mechanical properties of three novel polymer-based pellet compounds with post-industrial SCGs, i.e., injection molding grade polylactic acid/SCGs, recycled low-density polyethylene/SCGs, and high-density polyethylene/SCGs, were herein investigated to evaluate their printability, defining their extrusion temperatures (190 °C and 170 °C). Results showed suitable viscosity ranges (133.6–839.7 Pa∙s) and accurate tensile values comparable with literature, e.g., ~ 1–3% minimum relative standard deviations (polylactic acid/SCGs), or conventional manufacturing, e.g., elastic moduli of 107.4 MPa (recycled low-density polyethylene/SCGs) and 587 MPa (high-density polyethylene/SCGs). Their use with large-format 3D printers was assessed thanks to nonplanar samples with complex overhang geometries, reaching a maximum curvature angle of 32° and fabricating overhangs up to 25° without supports. According to the tests, especially polylactic acid/SCGs, a bio-based compound, and recycled low-density polyethylene/SCGs, a fully recycled material, can be used for large-format 3D printing applications with complex geometries, e.g., furniture, interior, and exhibition design. This work paves the way for new materials for large-format additive manufacturing, reducing the need for 3D printing grade feedstock, cutting costs and consumption from filament processing, and fostering material waste reduction practices. [ABSTRACT FROM AUTHOR]

A typical halogen-free flame-retardant (HFFR) formulation for electric cables may contain polymers, various additives, and fire-retardant fillers. In this study, composites are prepared by mixing natural magnesium hydroxide (n-MDH) with linear low-density polyethylene (LLDPE) and a few types of ethylene–octene copolymers (C8-POE). Depending on the content of LLDPE and C8-POE, we obtained composites with different crystallinities that affected the final mechanical properties. The nucleation effect of the n-MDH and the variations in crystallinity caused by the blending of C8-POE/LLDPE/n-MDH were investigated. Notably, in the C8-POE/LLDPE blend, we found a decrease in the crystallization temperature of LLPDE compared to pure LLDPE and an increase in the crystallization temperature of C8-POE compared to pure C8-POE. On the contrary, the addition of n-MDH led to an increase in the crystallization temperature of LLDPE. As expected, the increase in the crystallinity of the polyolefin matrix of composites led to higher elastic modulus, higher tensile strength, and lower elongation at break. It has been observed that crystallinity also influences fire performance. Overall, these results show how to obtain the required mechanical features for halogen-free flame-retardant compounds for electric cable applications, depending on the quantities of the two miscible components in the final blend. [ABSTRACT FROM AUTHOR]

This study examines the effects of biodegradable mulches on melon production and quality in a Mediterranean environment, specifically focusing on Mater-Bi and Ecovio in comparison to conventional (low-density polyethylene) LDPE mulch. Biodegradable mulches influenced soil temperature, with Mater-Bi maintaining higher maximum soil temperatures conducive to crop growth, while Ecovio exhibited lower maximum temperatures beneficial in hot summer months. Results revealed a significant increase in melon yield with biodegradable mulches, with both Ecovio and Mater-Bi demonstrating higher yields at approximately 20.41 t ha−1, showing an improvement of 23.4% compared to LDPE. Although mulching did not impact the number, weight, or distal diameter of marketable fruits, it affected the apical diameter, with Ecovio-treated plants displaying an 8.4% larger apical diameter compared to the average of all treatments. Furthermore, mulching influenced fruit quality parameters such as consistency, pulp thickness, sugar content, and anti-oxidant activity, with Mater-Bi exhibiting the best performance. Since both Mater-Bi and Ecovio possess strengths and weaknesses, selecting the optimal mulch depends on the farmer's specific objectives and local growing conditions. Overall, the study suggests that biodegradable mulches, particularly Ecovio, offer a sustainable alternative to traditional plastic films, contributing to environmental preservation and enhancing melon yield and quality in Mediterranean agricultural settings. [ABSTRACT FROM AUTHOR]

The high rate of perishability of fruits such as cagaita (Eugenia dysenterica DC.), seriguela (Spondias purpurea L.), mangaba (Hancornia speciosa Gomes) and pitomba (Talisia esculenta Radlk.) makes it necessary to develop adequate conservation techniques to increase post-harvest shelf life. The aim of this research was to evaluate the post-harvest quality attributes of cagaita, seriguela, mangaba and pitomba fruits stored in different types of packaging during certain periods. The treatments were defined by the combination of three types of packaging (low-density polyethylene (LDPE), polyvinyl chloride (PVC) and without packaging) and seven storage periods. Total soluble solids, titratable acidity, hydrogen potential (pH), fruit firmness and loss of fresh mass were analyzed. Fruits packaged with LDPE presented the lowest values of fresh mass loss: 2.7, 2.3, 4.2 and 1.1% for cagaita, seriguela, mangaba and pitomba, respectively. Furthermore, LPDE packaging maintained the quality attributes in all fruits analyzed. PVC packaging was more efficient in maintaining fruit firmness, with average values of 0.03 N. Atmospheric modification techniques, such as LDPE and PVC packaging, make it possible to reduce metabolic activity, ensuring better post-harvest quality and increasing the storage period of fruits that occur in the semiarid region of Minas Gerais. [ABSTRACT FROM AUTHOR]

Biopolymer-based films are a promising alternative for the food packaging industry, in which petrochemical-based polymers like low-density polyethylene (LDPE) are commanding attention because of their high pollution levels. In this research, a biopolymer-based film made of chitosan (CS), gelatin (GEL), and glycerol (GLY) was designed. A Response Surface Methodology (RSM) analysis was performed to determine the chitosan, gelatin, and glycerol content that improved the mechanical properties selected as response variables (thickness, tensile strength (TS), and elongation at break (EAB). The content of CS (1.1% w/v), GEL (1.1% w/v), and GLY (0.4% w/v) in the film-forming solution guarantees an optimized film (OPT-F) with a 0.046 ± 0.003 mm thickness, 11.48 ± 1.42 mPa TS, and 2.6 ± 0.3% EAB. The OPT-F was characterized in terms of thermal, optical, and biodegradability properties compared to LDPE films. Thermogravimetric analysis (TGA) revealed that the OPT-F was thermally stable at temperatures below 300 °C, which is relevant to thermal processes in the food industry of packaging. The reduced water solubility (WS) (24.34 ± 2.47%) and the improved biodegradability properties (7.1%) compared with LDPE suggests that the biopolymer-based film obtained has potential applications in the food industry as a novel packaging material and can serve as a basis for the design of bioactive packaging. [ABSTRACT FROM AUTHOR]

Previous studies indicate that traditional asphalt mixtures lack the ability to withstand the stresses caused by heavy traffic volumes under high temperatures. To enhance the rutting resistance of flexible pavement under high levels of temperature and loading, extensive laboratory experiments were carried out. A 60/70 grade bitumen was used as a neat sample for comparison. The study introduced three distinct polymers, polypropylene (PP), low-density polyethylene (LDPE), and acrylonitrile butadiene styrene (ABS), at varying concentrations by weight into the neat bitumen. Initially, conventional tests were performed to evaluate the conventional properties of both the neat and modified bitumen, while aggregate tests assessed the mechanical properties of the aggregates. Subsequently, a Marshall mix design was performed to determine the optimum bitumen content (OBC) in the asphalt mixture. Finally, wheel-tracking tests were performed under a specific load and temperature to investigate the rutting behavior of the modified asphalt mixtures. The results of this comprehensive study revealed that the modified asphalt mixtures displayed improved resistance to rutting compared to the neat asphalt mixture. Furthermore, it was also observed that the LDPE exhibited a superior performance against rutting, followed by the PP and ABS. At polymer contents of 3%, 5%, and 7%, the LDPE achieved reductions in rut depth of 13%, 24%, and 33%, respectively, outperforming both PP- and ABS-modified asphalt. These findings not only enhance our understanding of asphalt behavior under diverse conditions but also highlight the potential of plastic-modified asphalt as an effective solution for mitigating rutting problems in road pavements. By incorporating plastic modifiers into asphalt mixtures, this approach aligns with the principles of sustainable construction by reducing plastic waste while improving pavement durability and performance. [ABSTRACT FROM AUTHOR]

Microplastic degradation by bacteria can degrade low-density polyethylene (LDPE). This study aimed to analyze the potential of Ambon Bay bacteria for microplastic degradation, the condition of microplastics after degradation, and identification of the potential for microplastic degradation. The results of isolation revealed as many as 20 bacterial isolates, which correlated with physicochemical conditions in the waters of Ambon Bay. Nine of them could degrade microplastics as indicated by the presence of a clear zone, namely KA1, KA2, KA3, KA4, KA5, KA9, KA10, KS6, and KS8. They were checked for biofilm formation, microplastic hydrophobicity, and percentage of microplastic weight reduction. Four isolates with the highest percentage of microplastic weight reduction on day 40 were KA1, KA2, KA3, and KA10 at 36.19%, 10.16%, 28.39%, and 17.07%, respectively. The results of LDPE microplastic degradation showed differences using field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM/EDS), attenuated total reflection-fourier transform infrared (ATRFTIR), and X-ray diffraction (XRD). The bacterial isolates identified were KA1 (Bacillus cereus), KA2 (Bacillus toyonesis), KA3 (Bacillus paramycoides), and KA10 (Escherichia coli). Indigenous bacteria from the waters of Ambon Bay have the potential to degrade LDPE microplastics, which causes structural changes, decreased crystallinity, weight, and C=C groups in microplastics after degradation, with bacterial isolate KA1 identified as Bacillus cereus showing the best potential with degradation of LDPE microplastics by 36.19%. [ABSTRACT FROM AUTHOR]

Although crumb rubber (CR) modified bitumen has been widely used in bitumen pavement, the issue of storage stability has not been resolved. Waste low-density polyethylene (LDPE), a new modifier, has been introduced to improve the performance of CR-modified bitumen. However, the interaction behavior among LDPE with different ultraviolet (UV) aging degrees, crumb rubber, and bitumen is not clear, depending on the environment and source. In this study, virgin LDPE (LDPE-0)/CR blends, LDPE with 8 days UV aging (LDPE-8)/CR blends and LDPE with 64 days UV aging (LDPE-64)/CR blends were prepared by melt compounding using a twin-screw extruder and mixed with bitumen. The samples were evaluated by various tests such as dynamic shear rheometer (DSR) tests, storage stability, fluorescence microscopy, and scanning electron microscope (SEM). Then, molecular dynamics (MD) simulation was used to explore the interaction behavior between LDPE/CR blends with different UV aging degrees and bitumen. The virgin bitumen model was validated by density, radial distribution function (RDF), and glass transition temperature (Tg). The interaction behaviors were characterized based on diffusion coefficient and concentration distribution. The results showed that LDPE/CR blends were able to improve the rheological properties and storage stability, especially in LDPE-8/CR-modified bitumen. From the microscopic analysis, it was also observed that a network of LDPE/CR blends in the modified bitumen was well dispersed. Furthermore, the addition of LDPE/CR blends inhibited the aggregation behavior of the light component and slowed down the diffusion rate of bitumen molecules. The research findings provide insights for improving the storage stability of bitumen. [ABSTRACT FROM AUTHOR]

This research investigates the microbial degradation of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) plastics by Bacillus sp., Proteus sp., Pseudomonas sp., and Salmonella sp. The study employs a systematic approach, isolating microorganisms from plastic-contaminated soil and subjecting them to a series of biochemical tests for identification. The research evaluates the weight loss of LDPE and HDPE over two months, revealing varying degrees of degradation among the bacterial strains. Results suggest a potential greater susceptibility of HDPE to microbial degradation. Scanning Electron Microscopy (SEM) analysis provides high-resolution images of the plastic surface, indicating structural changes and biofilm formation during degradation. The findings highlight the unique enzymatic capabilities of each strain and underscore the significance of SEM in elucidating microbial interactions with plastics. The study prompts discussions on optimization, synergistic effects, and the identification of key enzymes in plastic degradation, emphasizing the importance of microbial strategies for waste management. Overall, this research contributes valuable insights into the potential of bacterial strains for addressing plastic pollution challenges. [ABSTRACT FROM AUTHOR]

Plastic recycling facilities (PRF) are one of microplastic sources that may release into the environment. This study aims to identify the abundance and characteristics of microplastics potentially released from a PRF in Indonesia. Analysis of raw materials in the influent of the wastewater treatment plant (WWTP) showed a microplastic abundance of 485 particles/L. The dominant type of microplastic was the 2.5 μm - 5 mm size of fragmented highdensity polyethylene (HDPE). In the effluent of floating clarifier 3, the microplastic abundance detected was 98 particles/L, with low-density polyethylene (LDPE) as the dominant fragmented plastic ranging from 1.2-2.5 μm. Meanwhile, in the WWTP sludge, microplastics were identified with an abundance of 364.81 particles/kg. The microplastics found in the sludge were predominantly in the fragment form, composed of HDPE, with sizes ranging from 0.2-2.5 µm. This information is crucial for understanding the extent to which PRFs contribute to microplastic pollution in the environment. These findings emphasize the importance of implementing more effective wastewater management technologies in PRFs to reduce the release of microplastics into the environment. [ABSTRACT FROM AUTHOR]

Active food packaging incorporated with natural plant extracts as food preservatives, which will totally replace chemical preservatives gradually, are of major interest. Sequentially to our and other scientists' previous work, in this paper we present the results of a study on the development of a novel active food packaging film based on the incorporation of a natural-halloysite/carvacrol-extract nanohybrid with the commercially used low-density polyethylene. The corona-treatment procedure was employed to incorporate a natural preservative on to the optimum final film. Packaging films are formatted with and without incorporation of natural-halloysite/carvacrol-extract nanohybrid and are coated externally, directly or via corona-treatment, with carvacrol essential oil. Mechanical, physicochemical, and preservation tests indicated that the low-density polyethylene incorporated perfectly with a natural-halloysite/carvacrol-extract nanohybrid. The extra external coating of the film with pure carvacrol extract using the corona-treatment technique led to approximately 100% higher Young Modulus values, slightly decreased ultimate strength by 20%, and exhibited almost stable elongation at break properties. The water vapor and oxygen properties were increased by 45 and 43%, correspondingly, compared to those of pure low-density polyethylene film. Finally, the antioxidant activity of the corona-treated film increased by 28% compared to the untreated film coated with carvacrol because of the controlled release rate of the carvacrol. [ABSTRACT FROM AUTHOR]

The accumulation of microplastics (MPs) in the environment has been a bottleneck for scientific society. Several approaches have been described as possibilities for reducing MPs in aquatic and terrestrial ecosystems; however, most of them are not environmentally friendly. Filamentous fungi (Ff) cells are currently considered a promising solution as a treatment for MPs. Therefore, the present study reports the potential ability of Ff isolated from mangrove sediments to biodegrade low-density polyethylene MPs (LDPEMPs). Six Ff strains were grown in batch cultures for 28 days, and one of them, Aspergillus sp. (AQ3A), showed the most prominent profile to biodegrade polymeric compounds. After morphological and molecular analysis, all strains were identified as belonging to the genera Aspergillus (MQ1C, AQ2A and AQ3A), Penicillium (MQ1A), and Trichoderma (MQ1B and MQ2A). The strain Aspergillus sp. (AQ3A) showed the most promising results with a LDPEMPs reduction rate of 47% and biomass formation of 0.0890 g·mL−1. Complementary studies with Aspergillus sp. (AQ3A) using Fourier-transform infrared spectroscopy (FTIR) highlighted changes in the molecular structure of LDPEMPs. These results indicate that Ff can contribute to the biodegradation of LDPEMPs. However, other parameters, mainly associated with the enzymes that are involved in this biodegradation process, need to be explored. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are prevalent environmental pollutants due to their durable composition, extensive use, and improper disposal. Despite their widespread presence, rivers have received less attention in microplastic research than other water bodies. This study focused on investigating the origins, prevalence, spatial distribution, and physicochemical characteristics of microplastics in the surface waters of the Balu River, located in Dhaka, Bangladesh. Surface water samples were collected at six sampling sites of Balu River (each about 1–5 km apart) adjacent to the footwear industry, jute factory, textile mill, paper mill, agro and beverage factory, and cement plant. The study found that the average concentration of microplastics in the sampled water bodies was 102.5 ± 12.83 (items/l). Samples near the textile mill had the highest microplastic abundance (122 ± 18 items/l), while the cement plant had the lowest (58.5 ± 8 items/l). Analysis using a stereomicroscope revealed that fibers (29%), microplastics smaller than 100 µm (45%), and transparent microplastics (19%) were the most prevalent types observed in terms of shape, size, and color, respectively. Furthermore, scanning electron microscopy (SEM) observation suggested the potential for additional degradation of these microplastics into smaller particles, potentially reaching the nanoplastic scale. Additionally, Fourier transform infrared (FTIR) analysis identified 07 distinct polymer types among the microplastics: nylon (24%), polyvinyl chloride (19%), high-density polyethylene (17%), low-density polyethylene (14%), polystyrene (12%), polypropylene (7%), and nitrile (7%). The findings of this study serve as a crucial indicator of microplastic contamination, providing valuable insights into the sources and magnitude of microplastic pollution within the significant freshwater ecosystem of Balu River, Bangladesh, particularly focusing on its river systems. [ABSTRACT FROM AUTHOR]

There is always a vital need for more robust, affordable, and multifunctional materials to satisfy the demands of industrial consumers. Therefore, polymer matrix composites (dual and hybrid matrix) have become popular with multiple fillers to meet these needs. Graphene nano-platelet (GNP) and Carbon fibre (CF) are popular among those fillers due to their superior properties, such as good mechanical, thermal, and electrical properties. Low density polyethylene (LDPE), Polystyrene (PS), GNP, and CF are popular and heavily used in the packaging, automotive, and aerospace industries. However, it would be good to look at how these areas have evolved over the last few decades. Hence, this review focuses on a comparison of LDPE and PS as a matrix and GNP and CF as a filler, considering the content that determines the overall performance of blends and composites. The literature was screened for the last few decades. The blends and/or composites produced by a twin-screw extruder were included. A total of 1628 relevant papers were retrieved from all databases. Based on the review, it was deduced that more research should be needed in areas such as the aerospace industry to identify optimum content. Most of the analysis showed that factors such as filler surface area, dispersion, and content affect overall blends and composites' performance in terms of mechanical properties, especially elastic modulus and tensile strength, and other properties. Based on the review, it was realised that using 20 and 30 wt%, 2 and 30 wt%, 2 and 4 wt%, and 20 and 30 wt% filler was the most common combination giving the optimum content for LDPE, PS, GNP, and CF, respectively. EMS and TSH changes of the composites were calculated according to their optimum content. Overall, LDPE and PS are good in packaging areas, but their mechanical properties still need to be improved for use in industries such as automotive, aerospace etc. Due to the advantages of GNP and CF, they are used in different applications, such as electrical devices, medical tools, and automobile vehicles. However, these properties are affected easily by interfacial adhesion, dispersion, and aggregation. Many researchers have searched these parameters and analysed how to prevent the negative effects of these parameters. In conclusion, this review will be helpful for researchers and industrial people to be aware of the state-of-the-art of carbon-based composites and the evolution of LDPE, PS, GNP, and CF.

In recent decades, plastic waste management has become one of the main environmental challenges for today's society. The excessive consumption of so-called single-use plastics causes continuous damage to ecosystems, and it is necessary to find alternatives to recycle these products. In this work, a mechanical and hygrothermal characterisation of novel plaster composites incorporating LDPE waste in their interior was carried out. Thus, prefabricated plasterboards have been designed with a partial replacement of the original raw material with recycled LDPE in percentages of 5–10–15% by volume. The results show how these new composites exceeded the 0.18 kN minimum breaking load in panels in all cases, while decreases in density and thermal conductivity of up to 15% and 21%, respectively, were obtained. In addition, an increase of 3.8%in thermal resistance was obtained by incorporating these new gypsum boards in lightweight façade walls through simulations. In this way, a new pathway was explored for the recovery of these wastes and their subsequent application in the construction sector. [ABSTRACT FROM AUTHOR]

In this paper, linear low-density polyethylene (LLDPE) fibers were stabilized by ultraviolet ray (UV) irradiation, which provided a new treatment method for fabricating carbon fiber precursors. LLDPE chips were blended with a photo-initiator 4-chlorobenzophenone (4-CBP) and a crosslinker 1,2-polybutadiene (1,2-PB) to obtain spun particles, and then they were melt spun into the fibers. Then, UV irradiation of the as-spun fibers was performed to obtain precursors. An orthogonal experimental design investigated the effects of the ingredient ratio LLDPE:1,2-PB and UV irradiation time on the fiber gelation. The results show that the factor's order of influence was: ingredient ratio > UV irradiation time. The fiber gelation reaches a maximum of 67.51% at a dosage ratio of LLDPE:1, 2-PB of 97:2, and a UV irradiation time of 30 min. The UV irradiation introduced the crosslinking structure of LLDPE fibers, and the melting temperature of UV-XLPE fibers shifts toward lower temperatures, and the crystal size of the fibers decreased with increasing UV irradiation time. However, longer irradiation time does not beneficially affect the gelation degree. The low cost and feasible crosslinking method in this study offer the possibility of wide application of low-cost polyethylene-based carbon fibers. [ABSTRACT FROM AUTHOR]

The disposal and management of waste lithium-ion batteries (LIBs) and low-density polyethylene (LDPE) plastics pose significant environmental challenges. Here we show a synergistic pyrolysis approach that employs spent lithium transition metal oxides and waste LDPE plastics in one sealed reactor to achieve the separation of Li and transition metal. Additionally, we demonstrate the preparation of nanoscale NiCo alloy@carbon nanotubes (CNTs) through co-pyrolysis of LiNi0.6Co0.2Mn0.2O2 and LDPE. The NiCo alloy@CNTs exhibits excellent catalytic activity (Eonset = ~0.85 V) and the selectivity (~90%) for H2O2 production through the electrochemical reduction of oxygen. This can be attributed to the NiCo nanoalloy core and the presence of CNTs with abundant oxygen-containing functional groups (e.g., –COOH and C–O–C), as confirmed by density function theory calculations. Overall, this work presents a straightforward and green approach for valorizing and upcycling various waste LIBs and LDPE plastics. Waste lithium-ion batteries and low-density polyethylene plastics present environmental issues. Herein, the authors demonstrate a synergistic pyrolysis approach for efficient and selective lithium extraction and upgrading of transition metal-carbon composites. [ABSTRACT FROM AUTHOR]

Featured Application: The findings from this research may have a specific and so far unique application in creating new packaged food products that are not traditionally distributed as such. The results show that the selection of proper packaging material with good thickness, transparency and permeability characteristics along with favorable storage conditions can help to preserve the antioxidant compounds of fresh-cut nettle leaves for 14 days. Green leafy vegetables are very challenging in terms of storage and preservation, while packaging in controlled conditions with the selection of appropriate polymer material is crucial for maintaining their nutritional value and quality. Various packaging materials have different gas and water vapor permeability as well as physicochemical properties that can create a specific environment inside the package, therefore affecting the chemical composition, sensory characteristics, and overall quality of packed leafy vegetables. Stinging nettle is an edible plant with a high antioxidant content, making it a valuable leafy vegetable. Therefore, this study aimed to evaluate the influence of four packaging materials (biaxially oriented polypropylene (BOPP), low-density polyethylene (LDPE), polyamide/polyethylene (PA/PE), and polylactic acid (PLA)) on the antioxidant content of packed fresh nettle leaves during 14-day storage. Ascorbic acid content was the highest after 6 days of storage, equally well preserved in all tested films, with an average of 86.74 mg/100 g fm (fresh mass). After 14 days of storage, the total phenolic content was best preserved when packed in LDPE. The content of caffeoylmalic and chlorogenic acids was the highest in LDPE after 6 days. In addition, leaves packed in LDPE after 6 days of storage had the highest content of all photosynthetic pigments. According to FRAP analysis, the antioxidant capacity was best maintained in LDPE (at the 14th day, the measured capacity was 43.61 µmol TE/g). This study shows that the type of packaging material (BOPP, LDPE, PA/PE, and PLA) and storage duration (6 and 14 days) have a great impact on the level of antioxidant compounds in the nettle leaves, where LDPE and BOPP can be highlighted as the most favorable for the preservation of total and individual phenolic compounds, photosynthetic pigments, and antioxidant capacity. [ABSTRACT FROM AUTHOR]

Four-dimensional-printed smart materials have a wide range of applications in areas such as biomedicine, aerospace, and soft robotics. Among 3D printing technologies, fused deposition molding (FDM) is economical, simple, and apply to thermoplastics. Cross-linked polyethylene (XLPE) forms a stable chemical cross-linking structure and shows good shape-memory properties, but the sample is not soluble or fusible, which makes it hard to be applied in FDM printing. Therefore, in this work, a new idea of printing followed by irradiation was developed to prepare 4D-printed XLPE. First, low-density polyethylene (LDPE) was used to print the products using FDM technology and then cross-linked by gamma irradiation was used. The printing parameters were optimized, and the gel content, mechanical properties, and shape-memory behaviors were characterized. After gamma irradiation, the samples showed no new peak in FTIR spectra. And the samples exhibited good shape-memory capabilities. Increasing the irradiation dose increased the cross-linking degree and tensile strength and improved the shape-memory properties. However, it also decreased the elongation at break, and it did not affect the crystallization or melting behaviors of LDPE. With 120 kGy of irradiation, the shape recovery and fixity ratios (Rr and Rf) of the samples were 97.69% and 98.65%, respectively. After eight cycles, Rr and Rf remained at 96.30% and 97.76%, respectively, indicating excellent shape-memory performance. [ABSTRACT FROM AUTHOR]

This study focuses on the Kadalundi estuary, Kerala's first community reserve, investigating the prevalence and impacts of microplastics on both the estuarine environment and selected fish species. This study presents the initial evidence indicating the consumption of microplastic particles by 12 commercially important edible fish species inhabiting the Kadalundi estuary. Analysis revealed significant accumulations of microplastic fibers within the surface water. In examining 12 fish species from demersal and pelagic habitats, microplastics were found in both the gastrointestinal tracts and gills. In the digestive tracts, microplastic fragments constituted the highest proportion (46%), while in the gills, microplastic fibers were dominant (52.4%). This study observed a prevalence of blue microplastics over other colors in both water and fish samples. Notably, demersal species showed a higher incidence of ingested microplastics. Polymer analysis identified Polypropylene (PP), Nylon, Low-Density Polyethylene (LDPE), Polyethylene (PE), Polypropylene isotactic (iPP), PE 1 Octene copolymer, and Rayon in water samples, while fish samples predominantly contained LDPE, PP, PE, and Nylon. Risk assessment utilizing the Polymer Hazard Index (PHI) categorized certain polymers as posing minor to moderate risks. Pollution Load Index (PLI) computations indicated moderate to high levels of microplastic contamination across various sampling sites in the estuary. Principal Component Analysis (PCA) revealed a lack of correlation between fish size and microplastic ingestion, underscoring environmental factors' influence on microplastic intake. The study emphasizes the implications of microplastic pollution on the fragile ecosystem of the Kadalundi estuary, posing potential risks to biodiversity and human health. [ABSTRACT FROM AUTHOR]

To fulfil the European Green Deal targets and implement a circular economy, there is an urgent need to increase recycling rates of packaging materials. However, before recycled materials can be used in food contact applications, they must meet high safety standards. According to the European Food Safety Authority (EFSA), a worst-case scenario must be applied and unknown substances must be evaluated as being potentially genotoxic. The Ames test, which detects direct DNA-reactive effects, together with chromatographic analysis is very promising to complement risk assessment. This study aims to evaluate the effectiveness of functional barriers in ten different samples, including virgin and recycled LDPE foils. FT-IR analysis did not show major differences between virgin and recycled films. Light microscopy revealed differences in quality and an increased number of particles. GC-MS analysis detected and quantified 35 substances, including eight unknowns. Using a miniaturized version of the Ames test, four of ten samples tested positive in two individual migrates up to a dilution of 12.5%. All virgin LDPE materials tested negative; however, recycled material F showed an increased mutagenic activity, with an n-fold induction up to 28. Samples with functional barriers lowered migration and reduced mutagenicity. Nonetheless, further investigations are needed to identify possible sources of contamination. [ABSTRACT FROM AUTHOR]

This document is a corrigendum for an article titled "Plastic biodegradation by in vitro environmental microorganisms and in vivo gut microorganisms of insects." The corrigendum addresses errors in the article, including an error in a section title and incorrect information in Tables 2 and 3. The corrected information is provided, and the authors state that these errors do not change the scientific conclusions of the article. The corrigendum also includes a note from the publisher stating that the claims expressed in the article are solely those of the authors and do not necessarily represent the views of the publisher or affiliated organizations. The provided document is a list of references for various scientific studies on the biodegradation of plastic by different insect larvae. The studies explore the ability of larvae from species such as Tribolium confusum, Zophobas atratus, Tenebrio molitor, Galleria mellonella, and others to degrade different types of plastics, including polystyrene and polyethylene. The research examines the effects of plastic diets on the gut microbiota of the larvae and investigates the potential for complete digestion and biodegradation of plastics. The studies provide valuable insights into the role of insects in plastic waste management and offer potential solutions for plastic pollution. [Extracted from the article]

Pyrolysis is a promising technology for transforming waste plastics (WPs) into high-value products. In the near future it will play a key role in the circular economy, as a sustainable and environmentally friendly method of managing this waste. Although the literature reports on the pyrolysis of plastics, it is focused on pure polymers. On the other hand, the state-of-the-art knowledge about the pyrolysis of mixed and contaminated WPs is still scarce. Industrial waste processing usually uses polymer mixtures containing various impurities that influence the pyrolysis process during chemical WPs recycling. In the paper the pyrolysis of three types of WPs: low density polyethylene (LDPE), polyvinyl chloride (PVC) and polyvinyl butyral (PVB) from repeated mechanical recycling of plastics, as well as their binary and ternary mixtures, is considered. The influence of particular components on the pyrolysis process is analyzed. The aim is to determine synergistic behavior of the mixtures during the pyrolysis process, which is important for increasing the efficiency and quality of the obtained bioproducts. Methods such as thermogravimetric (TG/DTG) analysis coupled with Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy (MS) are used. The variations in the initial and final temperature of pyrolysis, mass loss and mass loss rate are determined. The content of PVC significantly lowers the initial temperature and mass loss and increases the final temperature. The pyrolysis of the considered mixtures shows a noticeable synergism—in the initial stage of pyrolysis up to a temperature around 450 °C, the mass loss is accelerated compared to what is predicted by simple superposition. The inhomogeneity of the mixtures as well as the waste origin causes a significant variation in the activation energy. Three main conclusions are obtained: (i) if the waste does not contain PVC, the pyrolysis is nearly complete at a temperature around 500 °C at a heating rate of 10 °C/min, whereas PVC is not fully processed even at 995 °C; (ii) the synergistic effects affect significantly the pyrolysis process by accelerating some steps and lowering the activation energy; and (iii) the presence of PVC noticeably lowers the temperature of the first stage of PVB pyrolysis. The investigation results prove that chemical recycling of mixed LDPE, PVC and PVB waste can be an effective method of plastic waste management. [ABSTRACT FROM AUTHOR]

In recent years, the research and development in conductive polymer composites (CPCs) had gained considerable interests in both industry and academia as potential materials for electronic interconnects. These composites require to have the ability to conduct electric while maintaining sufficient flexibility while withstanding the bending, twisting, or stretching during service. To achieve the desired composite properties, the processing method and the parameters involved plays important role and ought to be investigated. In this study, the effect compounding parameters on the preparation of linear-low density polyethylene/carbon black (LLDPE/CB) polymer composite were carried out. Factors namely filler loadings, screw speed and maximum barrel temperatures were selected and their effects on the tensile properties and conductivity were analyzed in this research. It was observed that the increasing of filler loadings from 5 wt.% to 10 wt.% has increased the electrical conductivity from 1.11x10-2 S/m to 1.46x10-2 S/m. The pareto chart shows that the filler loading was important factors to the result of composite conductivity. Moreover, the main effect plot shows that the filler loading has the highest mean effect on conductivity as it is important for the formation of conducting path in composite. It was also established that the pareto chart also shows that filler loading and barrel temperature have the highest significant effect on LLDPE/CB polymer composite tensile properties. The changes in the combinations of factors affect the tensile properties as revealed by the main effect plots for LLDPE/CB CPCs. [ABSTRACT FROM AUTHOR]

A study was carried out on the luminescence excitation spectra and photoluminescence (PL) spectra as well as the luminescence kinetics of low-density polyethylene composites with different contents of CaGa2S4:Eu2+ phosphor filler. The phospholuminescence was attributed to the 4f65d → 4f7 transition of the Eu3+ ion and was greatest when the filler concentration was 7 vol.%. The dependence of the PL intensity on the excitation power density up to 0.3 W/cm2 was found to be linear, indicating that these phosphors can be used as visible radiation sources in various lighting systems. [ABSTRACT FROM AUTHOR]

Recently, plastic wastes are considered a main environmental problem, and many bacterial isolates were tested to biodegrade them. The low-density polyethylene (LDPE) plastic sheets were tested to be degraded by a marine bacterial consortium. The potent marine plastic degrading isolates were biochemically identified as Bacillus licheniformis, Bacillus subtilis, and Paenibacillus xylanilyticus using the BIOLOG identification system. The identification of the most potent plastic-degrading bacterium was confirmed as Bacillus licheniformis FMMA using the 16S rRNA gene sequence. This bacterial consortium was physiologically adjusted as follows: pH 7, temperature 35°C, inoculum size 4ml/ 100ml (1.0X107CFU/ ml), and an incubation period of 30 days. It led to 34.1% plastic loss of weight. The mechanical properties (maximum force and the elongation% at break) of these treated LDPE plastic sheets showed 7.49N and 112.2%, respectively, compared to that of B. licheniformis FMMA, which showed a 25.5% plastic weight loss, with maximum force and elongation% at a breakpoint of 8.9N and 114.2%, respectively. In addition, the plastic biodegradation was also estimated through a scanning electron microscopy and Fourier transform-infrared (FTIR) spectroscopy, were a great reduction in the intensity of the -CH2 peak appeared at 2900cm-1, and the disappearance of the -OH peak at 3500cm-1 was observed. [ABSTRACT FROM AUTHOR]

It is crucial to initiate appropriate storage conditions for garlic depending on its properties. Fungal contamination can reduce the quality of garlic through changes in its properties which result in its aroma alteration. This study aimed to evaluate the effects of treatments such as fungal infection (FI), material of packaging (MP), and storage duration (SD) on various characteristics of garlic. An electronic nose was used complementarily to trace the aroma changes as a non‐destructive indicator. The Fusarium oxysporum (FS), Alternaria embellisia (AL), and Botrytis allii (BT) fungi were adopted for inoculation. The low‐density polyethylene (LDPE) and silicone nano‐emulsions (SNE) were used for packing samples. The data were analyzed by diverse approaches such as ANOVA, PLS, PCA, LDA, and BPNN. The results revealed that the evaluated properties changed during the storage. The implementation of treatments altered the intensity of these changes. The highest values of weight loss (21.14%), color changes (50.21), and acidity (7.48) were observed in the FS‐infected samples kept in LDPE for 28 days. The accuracy of PCA, LDA, and BPNN in the multivariate analysis of aroma had an increasing‐decreasing trend. The best accuracy of PCA in categorizing the FI and MP treatments achieved in the twelfth day of storage (96%). The optimal accuracy of classifications based on FI and MP treatments was obtained at d#12 (100%) and d#24 (100%), respectively. The PLS exposed that the aroma changes in garlic had a high correlation with the changes of studied properties (R2 ≥.7), except for the mechanical properties. [ABSTRACT FROM AUTHOR]

There is always a vital need for more robust, affordable, and multifunctional materials to satisfy the demands of industrial consumers. Therefore, polymer matrix composites (dual and hybrid matrix) have become popular with multiple fillers to meet these needs. Graphene nano-platelet (GNP) and Carbon fibre (CF) are popular among those fillers due to their superior properties, such as good mechanical, thermal, and electrical properties. Low density polyethylene (LDPE), Polystyrene (PS), GNP, and CF are popular and heavily used in the packaging, automotive, and aerospace industries. However, it would be good to look at how these areas have evolved over the last few decades. Hence, this review focuses on a comparison of LDPE and PS as a matrix and GNP and CF as a filler, considering the content that determines the overall performance of blends and composites. The literature was screened for the last few decades. The blends and/or composites produced by a twin-screw extruder were included. A total of 1628 relevant papers were retrieved from all databases. Based on the review, it was deduced that more research should be needed in areas such as the aerospace industry to identify optimum content. Most of the analysis showed that factors such as filler surface area, dispersion, and content affect overall blends and composites' performance in terms of mechanical properties, especially elastic modulus and tensile strength, and other properties. Based on the review, it was realised that using 20 and 30 wt%, 2 and 30 wt%, 2 and 4 wt%, and 20 and 30 wt% filler was the most common combination giving the optimum content for LDPE, PS, GNP, and CF, respectively. EMS and TSH changes of the composites were calculated according to their optimum content. Overall, LDPE and PS are good in packaging areas, but their mechanical properties still need to be improved for use in industries such as automotive, aerospace etc. Due to the advantages of GNP and CF, they are used in different applications, such as electrical devices, medical tools, and automobile vehicles. However, these properties are affected easily by interfacial adhesion, dispersion, and aggregation. Many researchers have searched these parameters and analysed how to prevent the negative effects of these parameters. In conclusion, this review will be helpful for researchers and industrial people to be aware of the state-of-theart of carbon-based composites and the evolution of LDPE, PS, GNP, and CF. [ABSTRACT FROM AUTHOR]

This research work focuses on the development and analysis of copper-filled linear low-density polyethylene (LLDPE) coatings deposited on LLDPE substrate via a thermocompression process. A dry mechanical mixing technique is employed to mix the copper–LLDPE powders. This relevant technology aims to develop new solid lubricating layered composite coatings without a negative environmental impact. Four different materials of the coatings are considered, i.e., LLDPE + 2 wt.% Cu, LLDPE + 6 wt.% Cu, LLDPE + 10 wt.% Cu and LLDPE + 20 wt.% Cu. The microstructural characterizations indicate a good degree of dispersion and adhesion between the continuous and dispersed phases at 20 wt.% Cu coatings. The mechanical properties of the pure polymer and the fully filled composite materials are investigated experimentally using tensile tests and Micro-Vickers hardness. The stiffness, hardness and mechanical strength of the composites are enhanced. Friction tests are also carried out via a linear reciprocating sliding tribometer. The incorporation of copper powder has a significant improvement on the friction and wear properties of the developed coatings. Higher copper powder loading provides a lower friction coefficient and wear volume loss. The best tribological performances are obtained with the LLDPE + 20 wt.% Cu coating. The wear mechanism of the LLDPE substrate is severe adhesive wear, and it becomes mild abrasive wear in case of the 20 wt.% Cu coating. [ABSTRACT FROM AUTHOR]

Plastic recycling facilities deal with single‐ and mixed‐stream plastic waste. Clean single‐stream waste is sold as clean flake, or the flake is converted to pellets for material handling. The flake conversion process uses a conventional melt‐phase extruder to convert extruded filaments that are cooled and then pelletized. Friction extrusion (FE), a solid phase processing technique that has successfully extruded metal and metal matrix composites with desired properties, has never been utilized to address its ability to process plastic wastes. In this study, FE was performed on single‐stream low‐density polyethylene (LDPE) and single‐stream polypropylene (PP). Consolidated filaments of 2.5 mm diameter were extruded from different polymers. The energy efficiency of FE was estimated based on extrusion rates. A potentially 50%–80% reduction in energy cost was calculated for FE compared to the conventional melt extrusion process. Thermal properties of pellets and extruded filaments were measured to evaluate the effects of FE process on the molecular and morphological structures of LDPE and PP. The thermal properties of PP before and after FE were not significantly changed. For LDPE, the melting and crystallization temperatures increased by 3 and 7°C while the degree of crystallinity decreased by 3%, probably associated with side chain realignment under shearing. Highlights: Direct extruded polyolefin into filaments without melting via friction extrusion.Estimated over 50% energy reduction compared melt extrusion process.This novel mechanical process does not degrade polyolefin material. [ABSTRACT FROM AUTHOR]

Heat shrink sleeves (HSS) are multilayer polymers that provide corrosion resistance for welding joints of steel pipes. Within the HSS structure, the adhesive layer is a blend of components, such as ethylene vinyl acetate (EVA) and linear low‐density polyethylene (LLDPE). In this study, a systematic approach was employed to investigate the effect of the rheology and blend composition of the maleic anhydride‐modified EVA and maleic anhydride‐modified LLDPE (EVA‐g‐MA/LLDPE‐g‐MA) adhesive layer, prepared by melt processing, on its adhesion properties. Various characterization techniques were employed to investigate the local morphology of the prepared blends at different zones. Peel strength tests were used to characterize the adhesion strength of the prepared adhesives. Our findings demonstrate that the local distribution of EVA‐g‐MA within LLDPE‐g‐MA plays a crucial role in the adhesion strength of the adhesive. The results show that the adhesion strength enhanced by nearly 45% as the composition of EVA‐g‐MA at the surface went up by 20%, shifting the failure location from the epoxy/adhesive interface to the bulk of the adhesive layer. Our hypothesis of the decrease of EVA‐g‐MA intrachain bonding and increase in the EVA‐g‐MA free chain amount in the presence of LLDPE‐g‐MA to improve the adhesion properties was corroborated through our calorimetry results where the relative EVA‐g‐MA crystallinity decreased as LLDPE‐g‐MA was introduced to the blend. The findings of our study highlight the importance of rheological behavior and blend composition in obtaining optimized performance of adhesives within the HSS structure. Highlights: Compression molding of EVA‐g‐MA/LLDPE‐g‐MA induces a layered morphology.Local distribution EVA‐g‐MA/LLDPE‐g‐MA components influence their adhesion.EVA‐g‐MA at the interface improves the adhesion of EVA‐g‐MA/LLDPE‐g‐MA.LLDPE‐g‐MA suppresses the EVA‐g‐MA crystallinity.EVA‐g‐MA/LLDPE‐g‐MA composition affects adhesion at different temperatures. [ABSTRACT FROM AUTHOR]

Advanced recycling offers a unique opportunity for the circular economy, especially for mixed and contaminated plastics that are difficult to recycle mechanically. However, advanced recycling has barriers such as poor selectivity, contaminant sensitivity, and the need for expensive catalysts. Reported herein is a simple yet scalable methodology for converting mixed polyethylene (high-density and low-density polyethylene recycled polyethylene) into upcycled waxes with up to 94% yield. This high yield was possible by performing the reaction at a mild temperature and was enabled by using inexpensive and reusable table salt. Without table salt, in otherwise identical conditions, the plastic remained essentially undegraded. These upcycled waxes were used as prototypes for applications such as water- and oil-resistant paper, as well as rheology modifiers for plastics. Their performance is similar to that of commercial wax as well as rheology modifiers. A preliminary economic analysis shows that the upcycled waxes obtained by this table salt-catalyzed approach offer three times more revenue than those reported in the literature. This pioneering discovery opens the door for a circular economy of plastics in general and polyolefins in particular. [ABSTRACT FROM AUTHOR]

This study examines the applicability of an unknown composition waste plastic bag sample as bitumen modifier. The waste components were initially characterized to identify the type of plastics and the level of impurity. Asphalt binder performance was examined for rutting, thermal, and age resistance. The results revealed that the waste plastic bags, predominantly consisted of Low-Density Polyethylene (LDPE) and Linear Low-Density Polyethylene (LLDPE) and contained 6.1% impurities. The binder tests indicated that the waste plastic bags enhanced the rutting resistance of bitumen by one grade, with its modification more similar to LLDPE, rather than LDPE. The thermal degradation and aging properties of the modified binders demonstrated that the bitumen modified by the waste plastic bags exhibited slightly lower resistance to temperature and aging compared to virgin LDPE and LLDPE. This was attributed to the impurities contained in the waste plastic. In conclusion, the analyzed waste plastic bags proved to be suitable for use in binder modification, presenting a viable alternative to virgin LLDPE. [ABSTRACT FROM AUTHOR]

The physical properties as well as thermal and electrical stability of copper particles can be improved by surface protection, which mainly depends on the coating material. Our study was, therefore, focused on the rheological, thermal, mechanical and electrical characterization of polymer composites by comparing uncoated (Cu), silver-coated (Cu@Ag) and silica-coated (Cu@Si) copper flakes in low-density polyethylene at various volume concentrations (up to 40%). Interactions among particles were investigated by rheological properties, as these indicate network formation (geometrical entanglement), which is important for mechanical reinforcement as well as establishing an electric pathway (electrical percolation). The results showed that geometrical and electrical percolation were the same for Cu and Cu@Si, ~15%, while, surprisingly, Cu@Ag exhibited much lower percolation, ~7.5%, indicating the fusion of the Ag coating material, which also decreased crystal growth (degree of crystallinity). Furthermore, the magnitude of the rheological and mechanical response remained the same for all investigated materials, indicating that the coating materials do not provide any load transfer capabilities. However, they profoundly affect electron transfer, in that, Cu@Ag exhibited superior conductivity (74.4 S/m) compared to Cu (1.7 × 10−4 S/m) and Cu@Si (1.5 × 10−10 S/m). The results obtained are important for the design of advanced polymer composites for various applications, particularly in electronics where enhanced electrical conductivity is desired. [ABSTRACT FROM AUTHOR]