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In low‐density polyethylene (LDPE) production, low‐molecular‐weight species are used as chain transfer agents (CTAs). They reduce the degree of polymerization, which has an impact on the polymer properties, such as processability. To specifically adjust the product properties, a detailed understanding of the transfer kinetics to CTAs is indispensable. Thus, the transfer activity of various primary, secondary, and tertiary alcohols as well as diols was investigated experimentally between 120 °C and 250 °C at 2000 bar. The results were evaluated using the Mayo and chain length distribution (CLD) method, and the latter was found to give more reliable results. It was observed that the hydroxy group systematically increases transfer activity compared to alkanes. Additionally, a linear increase of transfer activity with the number of hydrogen atoms is found. [ABSTRACT FROM AUTHOR]

The aim of this research is to develop a composite antibacterial film for food packaging using low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyethylene-graft-maleic anhydride (PE-g-MA), and incorporating chitosan (CS) particles onto which ajwan essential oil (AEO) is adsorbed. The films were characterized using various techniques, including Fourier-transform infrared spectroscopy (FTIR), Gas chromatography/mass spectroscopy (GC-MS), X-ray diffraction (XRD), tensile testing, oxygen transmission rate (OTR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and antibacterial assays. FTIR results confirmed the presence of CS and/or AEO in the films. Mechanical testing indicated a decrease in tensile strength and an increase in elongation at break with the addition of AEO, while CS reduced elongation. In the sample containing only 7.5% chitosan (PE-7.5-0), the oxygen permeability was reduced to 910 cm2/m2·day·bar due to the presence of CS. However, the inclusion of AEO in the sample (PE-0-10) increased the oxygen permeability to 2200 cm2/m2·day·bar, which is higher than that of the control sample (PE-0-0) with an oxygen permeability of 1680 cm2/m2·day·bar. The antibacterial activity results demonstrated a synergistic inhibitory effect of CS and AEO. Data from GC-MS and inhibition zone (IZ) tests indicated that while chitosan alone does not exhibit significant antibacterial activity due to its incorporation in the bulk of the film, its combination with AEO enhances antibacterial efficacy. This enhancement occurs as the oil is adsorbed and protected from evaporation during the film formation process. Overall, the findings from this research suggest that the composite film PE-7.5-10, which possesses suitable mechanical properties and significant antibacterial activity, could be an effective candidate for food packaging applications. [ABSTRACT FROM AUTHOR]

In the present work, sugarcane bagasse (SCB) fibers were used as natural reinforcement to low-density polyethylene matrix to benefit from and get rid of unexploited Egyptian natural resources in bio-composites applications. The samples were prepared by injection molding processes using various fiber content (10 wt%, 20 wt% and 30 wt%). The fibers were treated chemically with 3% sodium hydroxide (NaOH) to improve compatibility and adhesion with the matrix. Maleic anhydride was added as a coupling agent to improve interfacial adhesion. The mechanical properties such as tensile and flexural tests were performed according to ASTM standards. The chemical resistance of fabricated composites was also examined. The results indicated that the alkali treatment modified the fiber surface and increased the interaction between the fiber and the matrix. They also showed that adding the coupling agent improved the interfacial adhesion between the fibers and the polyethylene. Additionally, the results showed that the maximum improvement of the fabricated composites with various fiber loadings was found at the 30 wt% treated coupled composites with tensile strength (17.5 MPa) and flexural (19.6 MPa). This reflected an enhancement in tensile strength by 41% and flexural strength by 72% at 30 wt% fiber compared to the neat polymer, respectively. The results also indicated that chemical resistance decreased with increasing fiber content. But it was found that the chemical resistance for aqueous solution 3.5 wt% Nacl was enhanced when the coupling agent was used. The greatest improvement in the resistance was observed for coupled treated SCB composite, followed by coupled untreated SCB composites. This reflected that the addition of maleic anhydride (MAPE) along with the composites improved the chemical resistance of the composites for aqueous solution 3.5 wt% Nacl. [ABSTRACT FROM AUTHOR]

Hydrocracking catalysis is a controllable route to plastic waste upgrading. However, the mismatched acid site-driven C-C cleavage and C=C hydrogenation process on metal restrict the efficiency and selectivity in conventional metal/acid bi-functional catalyst. Herein, we introduce Al deficiency in Si-O(H)-Al structural units of Pt/zeolite socony mobil-5 (Pt/ZSM-5) through discharge driven reduction (DR) process to precisely control the ratio of metal to acid, achieving hydrocracking of low-density polyethylene (LDPE) waste at 270 °C with 87.7% conversion and liquid fuel (C5-C21) selectivity of 77.8%. Pair distribution function (PDF) and nuclear magnetic resonance (NMR) spectroscopy demonstrate the partial absent Al sites further resulting short-range local disorder Si-O(H)-Al. Upon pyridine infrared spectroscopy (Py-IR) and CO diffuse reflectance Fourier-transform infrared (CO DRIFT) analysis, the extraction of Al modulates Brønsted acid density of Pt/ZSM-5 with DR process (Pt/Z5DR), improves the interaction between Pt and ZSM-5 support, enhances the cationic of Pt. The metal-acid balance and electron-deficient Pt favor the matching speed of light olefins hydrogenation and the cracking of macromolecule intermediates. Moreover, density functional theory (DFT) calculations identify the thermodynamic stability of Pt/Z5DR and moderate adsorption capability towards light olefins. This work confirms the great potential of precisely controlled molar of metal to acid in metal/zeolite catalysts for LDPE upcycling, providing a viable path for dealing with PE plastic wastes. [ABSTRACT FROM AUTHOR]

Low‐Density Polyethylene (LDPE) reactors have the potential for rupture because of thermal runaway from auto‐accelerating chemistry. Pockets of unmixed, highly reactive, LDPE constituents, called hot spots, are often generated by conditions within the reactor and are the main source of thermal runaway. Because of this, there is a need to define thresholds of hot spot conditions that produce runaway. Computational Fluid Dynamics is used to study an isolated LDPE sphere with varying initial temperature, initial catalyst concentration, and volume to determine which combinations promote thermal runaway. It is found that increasing both initial temperature and initial catalyst concentration increased thermal runaway likelihood, while, counter‐intuitively, hot spot volume has no effect. An LDPE runaway map is provided to quantify the combinations that result in safe reactor operation. This allows manufacturers to make more informed control actions and to determine safe reactor conditions based on local mixture composition and temperature alone. [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]

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]

Low-density polyethylene (LDPE) is identified as the primary constituent (approximately 18.9%) in plastic waste pollution. Crystalline structure, high molecular weight, and hydrophobic nature make LDPE recalcitrant to degradation. In the current study, the biodegradation of LDPE was studied by using three novel Malaysian mangrove bacterial isolates Brevundimonas naejangsanensis (strain MGS1), Arthrobacter crystallopoietes (strain SW4), and Arthrobacter pokkalii (strain PD2). Biodegradation of UV-treated LDPE was determined by the gradual increase in microbial count and production of laccase and lipase enzymes over a period of thirty days. All the isolates reduced the weight of the residual polymer and modified the chemical structure of LDPE by forming carbonyl and hydroxyl groups as a result of oxidation reactions by enzymes. Strain MGS1 reduced the maximum weight by 4.64 ± 0.5% and produced maximum laccase (2.19 ± 0.15 U/mL) and lipase enzyme (1.35 ± 0.05 U/mL). Field emission scanning electron microscopy (FESEM) showed visual images of bacterial colonization, and surface erosion (cracks/holes) on the LDPE surface. The production of enzymes reduced the hydrophobicity of the LDPE as evidenced by the biofilm formation, addition of new functional groups, surface erosion, and weight loss. The study is significant in addressing the biodegradation of plastic waste in Malaysia by exploring the mangrove microbiome. [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]

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]

Plastic waste can exist naturally for hundreds of thousands of years and harm humans, animals, and the environment. In this study, the energy and exergy performances (absorbed energy, energy efficiency, absorbed exergy, and exergy efficiency) of LDPE (low-density polyethylene) plastic particles assisted by microwave heating based on the experimental data as affected by microwave power, feeding load, and chamber volume were evaluated and analyzed. The results showed that as the microwave power raised from 500 to 900 W, the feeding load changed from 10 to 30 g, and the chamber volume decreased from 200 to 100 ml, (a) the absorbed energy at the heating time of 60 min increased from 19.73 kJ, 5.84 kJ, and 22.71 kJ to 37.69 kJ; (b) the energy efficiency for the whole heating process increased from 1.10%, 0.32%, and 1.26% to 2.09%; (c) the absorbed exergy at the heating time of 60 min increased from 0.308, 0.091, and 0.091 to 0.724 kJ; and (d) the exergy efficiency for the whole heating process increased from 0.017, 0.005, and 0.023 to 0.040%, respectively. [ABSTRACT FROM AUTHOR]

Abstract The aim of this research is to develop a composite antibacterial film for food packaging using low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyethylene-graft-maleic anhydride (PE-g-MA), and incorporating chitosan (CS) particles onto which ajwan essential oil (AEO) is adsorbed. The films were characterized using various techniques, including Fourier-transform infrared spectroscopy (FTIR), Gas chromatography/mass spectroscopy (GC-MS), X-ray diffraction (XRD), tensile testing, oxygen transmission rate (OTR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and antibacterial assays. FTIR results confirmed the presence of CS and/or AEO in the films. Mechanical testing indicated a decrease in tensile strength and an increase in elongation at break with the addition of AEO, while CS reduced elongation. In the sample containing only 7.5% chitosan (PE-7.5-0), the oxygen permeability was reduced to 910 cm2/m2·day·bar due to the presence of CS. However, the inclusion of AEO in the sample (PE-0-10) increased the oxygen permeability to 2200 cm2/m2·day·bar, which is higher than that of the control sample (PE-0-0) with an oxygen permeability of 1680 cm2/m2·day·bar. The antibacterial activity results demonstrated a synergistic inhibitory effect of CS and AEO. Data from GC-MS and inhibition zone (IZ) tests indicated that while chitosan alone does not exhibit significant antibacterial activity due to its incorporation in the bulk of the film, its combination with AEO enhances antibacterial efficacy. This enhancement occurs as the oil is adsorbed and protected from evaporation during the film formation process. Overall, the findings from this research suggest that the composite film PE-7.5-10, which possesses suitable mechanical properties and significant antibacterial activity, could be an effective candidate for food packaging applications.

Abstract 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 With the development of industry and modern manufacturing, nondegradable low-density polyethylene (LDPE) has been widely used, posing a rising environmental hazard to natural ecosystems and public health. In this study, we isolated a series of LDPE-degrading fungi from landfill sites and carried out LDPE degradation experiments by combining highly efficient degrading fungi in pairs. The results showed that the mixed microorganisms composed of Alternaria sp. CPEF-1 and Trametes sp. PE2F-4 (H-3 group) had a greater degradation effect on heat-treated LDPE (T-LDPE). After 30 days of inoculation with combination strain H-3, the weight loss rate of the T-LDPE film was approximately 154% higher than that of the untreated LDPE (U-LDPE) film, and the weight loss rate reached 0.66 ± 0.06%. Environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) were used to further investigate the biodegradation impacts of T-LDPE, including the changes on the surface and depolymerization of the LDPE films during the fungal degradation process. Our findings revealed that the combined fungal treatment is more effective at degrading T-LDPE than the single strain treatment, and it is expected that properly altering the composition of the microbial community can help lessen the detrimental impact of plastics on the environment.

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.

Multiwalled carbon nanotubes (MWCNTs) were prepared from low‐density polyethylene (LDPE) plastic waste using FeMo(x)@MgO catalysts with several FeMo contents (x=10, 30, and 50 %). Pyrolysis of waste LDPE and growth of CNTs over FeMo/MgO catalysts were performed at 450 and 750 °C, respectively. The results indicated that FeMoO4, Fe2(MoO4)3, MgFe2O4, MgMoO4, and Mg2Mo3O11 species were the main components of the calcined catalyst containing 50 %FeMo. However, free monometallic iron oxides and bimetallic oxides (MgFe2O4, and MgMoO4) were the components of the calcined catalyst containing 10 %FeMo. The FeMo content was found to correlate with the yield and quality of the carbon product. TEM images of the spent catalysts proved the formation of MWCNTs at all FeMo contents. The FeMo(30)/MgO catalyst was the most active in CNT production. Raman spectroscopy results proved the generation of the best quality MWCNTs at 30 %FeMo content. XRD analysis of the spent catalysts demonstrated that nanocomposite of Fe3C, Mo2C, MgO, and MWCNTs (FeMoC(x)@MgO/CNTs) was successfully synthesized. The electrochemical performance of FeMoC(x)@MgO/CNTs composites was evaluated as low‐cost supercapacitor nanoelectrodes. Large specific capacity values of 806, 978, and 1180 F g were achieved at the current density of 0.1 A g using nanocomposites with 10, 30, and 50 %FeMo contents, respectively. [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]

With the development of industry and modern manufacturing, nondegradable low-density polyethylene (LDPE) has been widely used, posing a rising environmental hazard to natural ecosystems and public health. In this study, we isolated a series of LDPE-degrading fungi from landfill sites and carried out LDPE degradation experiments by combining highly efficient degrading fungi in pairs. The results showed that the mixed microorganisms composed of Alternaria sp. CPEF-1 and Trametes sp. PE2F-4 (H-3 group) had a greater degradation effect on heat-treated LDPE (T-LDPE). After 30 days of inoculation with combination strain H-3, the weight loss rate of the T-LDPE film was approximately 154% higher than that of the untreated LDPE (U-LDPE) film, and the weight loss rate reached 0.66 ± 0.06%. Environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) were used to further investigate the biodegradation impacts of T-LDPE, including the changes on the surface and depolymerization of the LDPE films during the fungal degradation process. Our findings revealed that the combined fungal treatment is more effective at degrading T-LDPE than the single strain treatment, and it is expected that properly altering the composition of the microbial community can help lessen the detrimental impact of plastics on the environment. [ABSTRACT FROM AUTHOR]

Low-density polyethylene (LDPE) is widely used in food packaging and agricultural mulching, but its disposal generates macro, meso and microplastics that infiltrate the food chain and carry harmful substances. The present study aimed to improve remediation strategies for soils contaminated with LDPE and enhance the survivability of Eisenia fetida. The study dissolved LDPE in trichloroethylene and treated it with starch, hydrogen peroxide, nitric acid and acetic acid, initiating thermo-oxidative reactions. The treatment decreased LDPE's crystallinity index from 48.48% to 44.06% (single treatment), 44.06% to 40.02% (double treatment) and 40.02% to 32.98% (triple treatment), achieving a 15.5% reduction in crystallinity. LDPE microplastics with 40.02% crystallinity showed lower mortality rates in Eisenia fetida earthworms compared to those with 44.06% and 32.98% crystallinity and untreated LDPE. When introduced to E. fetida, microbiota in the earthworm casts included unidentified species from Pseudomonas and Zoopagomycota, known polyethylene degraders. Microbial analysis of treated LDPE microplastics showed changes in gut microbiota, including potential degraders from Aeromonas and Malassezia restricta. XRD (X-ray diffraction techniques analyses) and FTIR(Fourier Transform Infrared Spectroscopy) analyses provided insights into distinct LDPE degradation patterns, identifying hydroxyl and carboxylic groups as functional groups. The study also investigated the ability of altered microflora with treated microplastics to degrade LDPE, favouring decreased earthworm mortality rates. The crystallinity index of treated polyethylene further reduced from 40.02% to 23.58% after 21 days of exposure to E. fetida. This research advances the understanding of oxidised plastics' ecological impacts and will help to develop environmentally sustainable and biodegradable LDPE. [ABSTRACT FROM AUTHOR]

Technological growth and biodegradable waste natural fibers are significant choices in polymer matrix composite preparation because of their distinct qualities from monopoly matrix. During the fabrication process, the natural fiber faces poor compatibility and lack of adhesive behavior, resulting in reduced tensile strength and stiffness of the composite. The theme of the research is expanding the mechanical behavior of low‐density polyethylene (LDPE) composite by the exposure of sodium hydroxide‐treated coir fiber (CF) and barium titanate (BaTiO3) through an injection molding route. Influences of CF and BaTiO3 on metallographic, tensile, flexural, and impact strength and microhardness of LDPE composite are evaluated, and its outcomes are compared with mono LDPE. The surface morphology of the developed composite is exposed to homogenous dispersion of BaTiO3 with effective adhesive bonding with CF, which facilitates superior mechanical properties. The LDPE hybrid composite consists of 30 wt% CF and 2.5 wt% of BaTiO3 and is exploited about 69 ± 1.5 MPa of tensile strength, 54 ± 0.5 MPa of flexural strength, 4.9 ± 0.01 J of impact energy, and 31 ± 1.5HV of microhardness, this is greater than the mono LDPE (unreinforced). The enriched LDPE hybrid composite is suggested for automotive dashboard applications. [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]

Cellulose acetate (CA) is a sustainable alternative to low-density polyethylene (LDPE), which is a major source of plastic waste. However, the barrier properties and mechanical strength of CA may limit its application as single-use food plastic packaging. This study aims to overcome these limitations by incorporating polyethylene glycol (PEG) 1450 ranging from 10 to 50% w/w. PEG 1450 improved water vapor barrier but increased moisture content, though both values remained similar up to 50% w/w PEG 1450. CA bioplastic films showed significantly higher (p < 0.05) UV–Vis absorbances at 40% w/w PEG 1450, suggesting that a high concentration of PEG 1450 can prevent lipid oxidation but also increase opacity as reflected on the physical appearance. The reduced transparency was caused by aggregation and physical exclusion of PEG 1450 from the CA matrix which was observed under a scanning electron microscope (SEM). Meanwhile, PEG 1450 was miscible and compatible with CA at low concentration. In terms of mechanical properties, inclusion of PEG 1450 at 10 and 20% w/w improved the tearability of CA bioplastic films. In short, the incorporation of PEG 1450 improved barriers against UV and water vapor and tearability, making it superior to commercial LDPE plastic in some respects but lacking in others. Nonetheless, its advantages make it suitable for producing single-use food packaging, hence potentially replacing LDPE. [ABSTRACT FROM AUTHOR]

Plastics have been consistently produced for their practicality and convenience; however, unmanaged plastics often end up in the ocean and decompose into nano-plastics through photolytic decomposition and weathering, negatively affecting marine life. This can eventually affect humans via the food chain, highlighting the need for effective solutions. Microbial biodegradation has been proposed as a solution to minimize the impact of nano-plastics on the environment, and degradation byproducts can be used in microbial metabolic pathways. In this study, 57 bacterial strains were isolated and identified from a waste treatment facility. Bacterial strains with lipase activity were selected on Tween80 agar plates. Additionally, strains capable of growing on minimal salt agar plates supplemented with low-density polyethylene (LDPE) beads were selected. Incubation in a minimal salt medium with LDPE beads as the sole carbon source led to the selection of Pseudomonas plecoglossicida SYp2123, which is capable of degrading LDPE. This strain was subjected to high cell density culture, and Fourier-transform infrared spectroscopy revealed chemical changes on the surface of LDPE beads. Additionally, field-emission scanning electron microscopy confirmed substantial biodegradation of the surface. P. plecoglossicida SYp2123 was able to degrade LDPE beads. This discovery shows that P. plecoglossicida can potentially be used as an environmentally friendly approach for tackling issues associated with polyethylene waste. [ABSTRACT FROM AUTHOR]

Fused filament fabrication (FFF) has been widely adopted due to its simplicity and cost‐effectiveness. But until now, its application materials are still limited. Polyolefin material is one of the most commonly used plastics. However, low‐density polyethylene (LDPE) is rarely used in FFF due to the inadequate strength of the filaments and the warpage of the printed parts. In this work, polystyrene (PS) is added to LDPE to obtain blend filaments. After that, the filaments are used to validate the possibility of in situ microfibrillation directly in the process. The results show that the addition of PS can significantly improve the bending strength, bending modulus, and hardness without affecting the heat resistance and crystal transition of the composite. Besides, the PS dispersed phase can form microfibers under the influence of the shear field. The formation of microfibers can significantly enhance the mechanical properties of composites. The tensile strength and Young's modulus increase by 140% and 221%, respectively. The warping deformation and surface morphology of printed parts are also improved. This study provides a new idea for utilizing low‐strength polyolefin in 3D printing and achieving performance enhancement. [ABSTRACT FROM AUTHOR]

A multi-objective optimization (MOO) technique to produce a low-density polyethylene (LDPE) is applied to address these two problems: increasing conversion and reducing operating cost (as the first optimization problem, P1) and increasing productivity and reducing operating cost (as the second optimization problem, P2). ASPEN Plus software was utilized for the model-based optimization by executing the MOO algorithm using the tubular reactor model. The multi-objective optimization of multi-objective Bonobo optimisers (MOBO-I, MOBO-II and MOBO-III) are utilised to solve the optimization problem. The performance matrices, including hypervolume, pure diversity, and distance, are used to decide on the best MOO method. An inequality constraint was introduced on the temperature of the reactor to prevent run-away. According to the findings of the study, the MOBO-II for Problems 1 and 2 was the most effective MOO strategy. The reason is that the solution set found represents the most accurate, diversified, and acceptable distribution points alongside the Pareto Front (PF) in terms of homogeneity. The minimum operating cost, the maximum conversion and productivity obtained by MOBO-II are Mil. RM/year 114.3, 31.45 %, Mil. RM/year 545.3, respectively. [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]

The co-pyrolysis of polyethylene terephthalate (PET) with low-density polyethylene (LDPE) and high-density polyethylene (HDPE) was carried out in a batch steel pyrolyzer in order to convert the PET into pyrolysis oil as its pyrolysis alone resulted in wax and gases. The study also aimed to increase the aromatic content of pyrolysis oil by the interaction of degradation fragments of linear chains of LDPE and HDPE with the benzene ring of PET during the pyrolysis. The reaction conditions were optimized for a higher yield of pyrolysis oil which were found to be 500 °C pyrolysis temperature with a heating rate of 0.5 °Cs−1, 1 h reaction time and 20 g of the initial mass of polymer mixture having 20% PET, 40% LDPE and 40% HDPE. Waste aluminium particles were applied as an economical catalyst in the process. The thermal co-pyrolysis yielded 8% pyrolysis oil, 32.3 wax, 39.7 wt% gases and 20% coke while the catalytic co-pyrolysis produced 30.2% pyrolysis oil, 4.2% wax, 53.6 wt% gases and 12% coke. The fractional distillation of catalytic oil resulted in 46% gasoline range oil, 31% kerosene range oil and 23% diesel range oil. These fractions resembled the standard fuels in terms of their fuel properties as well as FT-IR spectra. The GC-MS analysis revealed that the catalytic co-pyrolysis favoured the formation of relatively short-chain hydrocarbons with olefins and isoparaffins as major components while the thermal co-pyrolysis formed long-chain paraffins. The naphthenes and aromatics were also found in higher amounts in the catalytic oil compared with the thermal oil. [ABSTRACT FROM AUTHOR]

Polymer-modified bitumen undergoes phase separation during storage due to a lack of compatibility between the polymers and bitumen. However, phase separation can be minimized via the addition of various compatibilizers. This study investigated low-density polyethylene (LDPE)-modified bitumen blends at 3, 6, 9, and 12% concentration of LDPE sourced from waste plastic films. Furthermore, the combined compatibilizers (1% of maleic anhydride-grafted polyethylene (PE-g-MA) and 0.15% sulfur) were added to LDPE-modified blends. The combination of compatibilizers significantly improved the softening point and storage stability while subsequently increasing the compatibility between recycled plastics (LDPE) and bitumen. The addition of PE-g-MA and sulfur decreased the melting temperature of LDPE up to 10 °C due to the swelling of the polymers compared to blends prepared with LDPE only. Higher thermal stability was observed for LDPE blends with PE-g-MA and sulfur than for the blends with LDPE only. The major weight loss for LDPE–based blends and LDPE blends in the presence of PE-g-MA and sulfur occurred at 380–520 °C and 400–540 °C, respectively. LDPE blends in the presence of compatibilizers showed lower phase angle at higher temperatures than neat LDPE blends, suggesting that the compatibilizers tend to form a complete polymer–bitumen network. It was concluded that incorporation of both sulfur and PE-g-MA enhanced the compatibility, thermal characteristics, and rheological properties of waste plastic-modified bitumen. [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]

Cross‐linking of polymers is an efficient method to tailor the end‐use properties of polymer materials. Cross‐linking using a chemical agent, e.g., dicumyl peroxide (DCP), allows for a spatially uniform network formation in the melt state. In addition, it is also associated with side reactions which influence the final properties of the plastic part. This work investigates the influence of DCP concentration on the tribological properties of a cross‐linked low‐density polyethylene (LDPE) grade. In particular, high DCP concentrations up to 20 phr are chosen in order to explore the effect of a high degree of cross‐linking. The viscoelastic properties below and above the melting temperature are studied in detail to support the interpretation of the tribological results. Rheological investigations allow one to monitor the cross‐linking of the long‐chain branched LDPE. The data and the subsequent optical analysis show that wear already is significantly reduced at a low DCP concentration of 1 phr because of the covalent bonds caused by cross‐linking. A high DCP concentration of 20 phr yields an increase of coefficient of friction which can be explained by the low stiffness and the resulting high contact area in the case of highly cross‐linked LDPE. [ABSTRACT FROM AUTHOR]

It is very necessary to take into account the importance of asphalt mixtures in providing high-performance asphalt roads, especially with the increase in traffic loads at the present time. So, the proposed methodology entails the selection of design binder amount not solely based on volumetric data but also on mixed performance tests. These performance tests assess the vulnerability of dense graded mixes to various anticipated failure modes that may arise in the flexible pavement during its service life. Indirect tensile strength is a notable performance testing method that is frequently employed. The indirect tensile strength test is recommended for assessing the comparative excellence of asphalt mixes in conjunction with laboratory mix design testing. Additionally, it aids in estimating the susceptibility of the mix to rutting or cracking. In this study, an in-depth analysis has been performed to assess the mechanical features of tensile strength, focusing on its comparison across various asphalt mixes. Fifteen asphalt mixes, with and without additives, were meticulously prepared and subjected to rigorous laboratory testing. A test was performed to assess the tensile strength of the mix utilizing the indirect tensile (ITS) strength testing method. Additionally, it is worth noting that there are three distinct variations of thin Hot Mix Asphalt (HMA) mixes based on aggregate gradation, specifically utilizing 12.5mm, 9.5mm, and 4.75mm Nominal Maximum Aggregate Size (NMAS). Furthermore, it is essential to mention that a single type of asphalt binder is employed, characterized by its penetration grade falling within the range of 40-50. Moreover, to enhance the features of the neat asphalt binder, two distinct types of polymers, namely Crumb Rubber Modifier (CRM) and Low-Density Polyethylene (LDPE), were employed as additives. These polymers were incorporated into the asphalt binder to augment its performance further. The blending operations were conducted utilizing a 15% crumb rubber modifier (CRM) content, along with varying percentages of low-density polyethylene (LDPE) added to the original asphalt binder at ratios of 2.5, 5, 7.5, and 10. The findings have demonstrated that the tensile strength of modified asphalt mixes exhibits an upward trend as the nominal maximum size is augmented, as observed through the utilization of the indirect tensile test. The improvement of the ITS of control mixes was further augmented by incorporating additives. In this study, it has been observed that the Indirect Tensile (ITS) magnitudes exhibit an upward trend to the NMAS and the concentration of polymers. Furthermore, it has been observed that ITS exhibits an upward trend as the Low-Density Polyethylene (LDPE) content is augmented in the presence of Crumb Rubber Modifier (CRM). [ABSTRACT FROM AUTHOR]

The mutual effects and the structure of interface in blends of low-density polyethylene (PE) and polycaprolactone (PCL) with different ratios of components (differing by 10 wt %) were studied. The creation of blended composites of this kind based on one polymer capable of photodegradation under the action of ultraviolet radiation and another polymer prone to hydrolytic degradation under the action of microbiota makes it possible to obtain materials with an enhanced ability to undergo fast abiotic and biotic degradation after use. Blended films with high PCL contents (over 80 wt %) showed mutual compatibility of polymers, forming a developed interfacial layer, which imparts increased tensile strength and hardness to the film. The phase inversion ranges were determined to be 10–30 wt % PCL (continuous PE phase with a discontinuous PCL phase), 40–60 wt % PCL (net-in-net structure) and 70–90 wt % (continuous PCL phase with a discontinuous PE phase). The composite containing 70 wt % PCL was characterized by the greatest defectiveness of internal structure, and the composite with 90 wt % PCL had the most optimum set of both mechanical and technological properties. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the efficiency of biosynthesized zinc oxide nanoparticles in fungal supernatant grown in kitchen wastewater with microelectronic sludge (FKMW-ZnO NPs) to be used in the degradation low-density polyethylene (LDPE) in aqueous solution. The photocatalysis process was optimized using response surface methodology as a function of four independent factors included LDPE concentrations x 1 (100–500 mg/100 mL), FKMW-ZnO NPs concentrations x 2 (10–100 mg/100 mL), time x 3 (1–6 h) and pH x 4 (4–9). The maximum photocatalysis of LDPE was 45.43% optimized with 229.96 mg LDPE/100 mL, 100 mg FKMW-ZnO NPs/100 mL at pH 7 and after one hour with R2 is 0.7377. Microstructure and chemical structure analysis showed a significant change in the chemical structure of the photocatalysis of LDPE because of FKMW-ZnO NPs. The mathematical predication model using a radial basis function neural network ensemble system (RBFNNES) provided more accurate prediction model 89.2857% with R2 = 0.8688. However, RBFNNES revealed that FKMW-ZnO NPs and LDPE have unstable behaviour towards the investigated factor and the interaction between these factors where the error was increasing with the increasing the time of neural network which indicates that the obtained efficiency in the optimization study might be not applicable in the large scales or in different environmental factors. More optimization with a wide range of factors is required to understand the applicability of FKMW-ZnO NPs in remediation of LDPE in the environment. [ABSTRACT FROM AUTHOR]

Optimization on an industrial scale is a complex task that involves fine-tuning the performance of large-scale systems and applications to make them more efficient and effective. This process can be challenging due to the increasing volume of work, growing system complexity, and the need to maintain optimal performance. Due to the significant power required for compression and the high costs of reactant materials, optimizing low-density polyethylene (LDPE) production to provide maximum productivity with a reduction of energy cost is required. However, it is not a simple process because the optimization problem of the LDPE tubular reactor consists of conflicting objective functions. Multi-objective neural network algorithm (MONNA) is a metaheuristic optimization method that provides a versatile and robust approach for solving complex, contradictory targets and diverse optimization problems that do not rely on specific mathematical properties of the problem. It is inspired by the structure and information-processing capabilities of biological neural networks. MONNA iteratively proposes solutions, evaluates its performance, and adjusts its approach based on feedback, which avoids complex mathematical formulations. In this work, we implement Multi-objective optimization neural network algorithm (MONNA) in LDPE tubular reactor for maximising productivity, conversion and minimising energy costs with three scenario of problem optimization, i.e. maximising productivity and reducing energy cost for the first problem (P1); increasing conversion and reducing energy costs for the second problem (P2); and increasing productivity and reducing by-products for the third problem (P3). The results show that the highest productivity, highest conversion, and lowest energy are 545.1 mil. RM/year, 0.314, and 0.672 mil. RM/year. The extreme points in the Pareto Front (PF) for various bi-objective situations provide practitioners with helpful information for selecting the best trade-off for the operational strategy. According to their preferences, decision-makers can use the resulting Pareto to decide on the most acceptable alternative. The decision variable plots show that both initiators in the reacting zone highly affected the optimal solution with the opposite action.

In this study, the weldability of wood–plastic composites (comprising 50 % wood flour and 50 % low-density polyethylene) was examined using an innovative self-reacting friction stir welding tool featuring a double-stationary shoulder design. The tool, made from hardened K340 Isodur tool steel with a hardness of 60 HRc, was tested by varying the tool rotational speed (600 to 2200 rpm) and linear welding speed (0.2 to 0.6 mm/s) across five different Revolutions Per Distance (RPD) values, which measure energy input per unit length. The visual appearance, macrostructure, and mechanical properties of the welded specimens were assessed. A statistical regression equation was developed to relate the RPD and rotational speed to the relative flexural strength of the specimens. The tool design produced high-quality welds with a uniform welding nugget and minimal defects. The relative flexural strength values for the samples ranged from 62.85 % to 99.18 % in the entry region and 66.64 % to 92.14 % in the exit region.

The common use of plastics in daily life has engendered gigantic amounts of waste plastics, which have a detrimental influence on the environment. Researchers have proposed several strategies for the recycling of waste plastics and their products. Among these, one strategy is to use them in the construction industry, particularly in asphaltic pavements. This study thus focused on the utilization of waste plastics, specifically Low-Density Polyethylene (LDPE) and High-Density Polyethylene (HDPE), as an additive in Asphalt Concrete (AC) mixes. Indirect Tensile Strength (ITS), Flow Time (FT), and Dynamic Modulus (DM) tests were used to investigate the moisture damage, permanent deformation, fatigue performance, and DM of the LDPE and HDPE modified AC mixes. According to the laboratory test results, the LDPE and HDPE modified AC mixes offer more resistance to moisture damage compared to the Control AC mixes. It was also concluded that asphalt mixes modified with the LDPE and HDPE attained 2.07 times and 1.26 times superior resistance to permanent deformation than the Control mixes. Furthermore, the LDPE and HDPE modified AC mixes outperformed the DM values of the Control mixes by 2.06 times and 1.41 times, respectively. In addition, it was determined that the LDPE and HDPE modified AC mixes exhibit 1.72 times and 1.39 times greater fatigue parameter values than their counterpart, suggesting superior fatigue resistance performance. The statistical models developed using Response Surface Methodology (RSM) revealed the highest values of the Coefficient of Determination (>0.80), adequate precision (>4.0), and lack-of-fit tests, indicating the model’s adequacy for predicting the response.

[Display omitted] After grafting the N , N -dimethyl- N , N -diallylammonium chloride (DADMAC) polymer to low-density polyethylene (LDPE) using plasma, the polyethylene surface acquired wettability with water. The synthesized graft copolymer turned out to be bactericidal against gram-positive Staphylococcus aureus and gram-negative Escherichia coli. [ABSTRACT FROM AUTHOR]

Introduction The aim of the research was to demonstrate the efficiency of microorganisms and the effectiveness of biodegradation techniques on Low-density polyethylene (LDPE) plastics. The research question was: What is the efficiency of LDPE-degrading microorganisms and the effectiveness of biodegradation techniques? Methods The systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles were obtained from Scopus, Web of Science (WOS), Embase, and Google Scholar. The DeCS/Mesh search terms were: Low-density polyethylene, efficiency, biodegradation, microbial consortia, fungi, bacteria. Inclusion criteria were: scientific articles that included bacteria, fungi, and microbial consortia reported as LDPE degraders that report the percentage of weight loss; articles published from January 2010 to October 2022, and publications in Spanish and English with open access. Exclusion criteria were: studies that do not report gravimetry, the biodegradation time of LDPE, and the genus or species of the polyethylene-degrading microorganism. Results Out of 483 studies found, 50 were included in this Systematic Review (SR). The most frequent study techniques were scanning electron microscopy (SEM), gravimetry, and fourier transform infrared spectroscopy (FTIR), and in the case of microorganisms, the most studied belonged to the genus Pseudomonas, Bacillus, and Aspergillus. Regarding the isolation place, the most frequent mentioned in the reviewed articles were landfill soil and sanitary landfill soil. The efficiency of LDPE-degrading microorganisms was higher in bacteria such as Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp., which obtained a range of DE of 9.00-70.00%, 24.00-64%, 1.15 – 61.00%, 45.00%, and 1.5-40% with DT of 4-150, 120, 4-150, 30, and 30-120 days, respectively; in the case of fungi, the main microorganisms are Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii with efficiencies of 54.34, 48.78, and 46.34%, in 90 days, respectively; and the most efficient microbial consortia were from Enterobacter spp. and Pantoea sp. with 38.00 – 81.00%, in 120 days; and, Pseudomonas protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp. with 55. 00 – 75.00% in 120 days. Conclusions The most efficient microorganisms in LDPE degradation are Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp.; in fungi Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii; and in microbial consortia, those formed by Enterobacter spp. and Pantoea sp., and that of P. protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp.; and the most effective techniques used in LDPE biodegradation are SEM, gravimetry, and FTIR.

Introduction The aim of the research was to demonstrate the efficiency of microorganisms and the effectiveness of biodegradation techniques on Low-density polyethylene (LDPE) plastics. The research question was: What is the efficiency of LDPE-degrading microorganisms and the effectiveness of biodegradation techniques? Methods The systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles were obtained from Scopus, Web of Science (WOS), Embase, and Google Scholar. The DeCS/Mesh search terms were: Low-density polyethylene, efficiency, biodegradation, microbial consortia, fungi, bacteria. Inclusion criteria were: scientific articles that included bacteria, fungi, and microbial consortia reported as LDPE degraders that report the percentage of weight loss; articles published from January 2010 to October 2022, and publications in Spanish and English with open access. Exclusion criteria were: studies that do not report gravimetry, the biodegradation time of LDPE, and the genus or species of the polyethylene-degrading microorganism. Results Out of 483 studies found, 50 were included in this Systematic Review (SR). The most frequent study techniques were scanning electron microscopy (SEM), gravimetry, and fourier transform infrared spectroscopy (FTIR), and in the case of microorganisms, the most studied belonged to the genus Pseudomonas, Bacillus, and Aspergillus. Regarding the isolation place, the most frequent mentioned in the reviewed articles were landfill soil and sanitary landfill soil. The efficiency of LDPE-degrading microorganisms was higher in bacteria such as Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp., which obtained a range of DE of 9.00-70.00%, 24.00-64%, 1.15 – 61.00%, 45.00%, and 1.5-40% with DT of 4-150, 120, 4-150, 30, and 30-120 days, respectively; in the case of fungi, the main microorganisms are Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii with efficiencies of 54.34, 48.78, and 46.34%, in 90 days, respectively; and the most efficient microbial consortia were from Enterobacter spp. and Pantoea sp. with 38.00 – 81.00%, in 120 days; and, Pseudomonas protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp. with 55. 00 – 75.00% in 120 days. Conclusions The most efficient microorganisms in LDPE degradation are Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp.; in fungi Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii; and in microbial consortia, those formed by Enterobacter spp. and Pantoea sp., and that of P. protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp.; and the most effective techniques used in LDPE biodegradation are SEM, gravimetry, and FTIR.

The distribution structure of dielectric fillers is attracting more attention in designing composites with excellent dielectric properties and energy storage performances. Barium titanate (BT) and polyvinylidene fluoride (PVDF) were introduced to low‐density polyethylene (LDPE) to build the dielectric structure by modulating the phase structure of PVDF/LDPE and the distribution behavior of BT. The results showed that BT particles can be selectively distributed in the phase structure of PVDF/LDPE by controlling the surface modification of BT, which contributed much to the enhancement of dielectric properties and energy storage performances. The dielectric constant and discharge energy density of the composites with the selective distribution of core‐shell structured BT@PE in the LDPE phase of PVDF/LDPE blend were increased by 51% and 95% in comparison with PVDF/LDPE blend, respectively. By simulating with finite element analysis (FEA), the increased internal polarization and the decreased electric field distortion of PVDF/LDPE/BT@PE due to BT@PE distributed in the LDPE phase and the small dielectric constant difference between the LDPE/BT@PE phase and PVDF phase were the factors to enhance the dielectric constant and breakdown strength, which consequently enhance the energy storage performances of the composites. Highlights: Phase structure constructed with BT and BT@PE selectively distributed in PVDF/LDPE.Co‐enhanced dielectric constant and breakdown strength of PVDF/LDPE/BT@PE.Modulated polarization and electric field due to BT@PE in the LDPE phase of composites. [ABSTRACT FROM AUTHOR]

The work investigated the effect of three types of metal sludge as an oxo-decomposing additive to polyethylene. Mechanical characteristics were studied before and after complex climatic exposure in a three-factor climate chamber (heat, light, humidity). Using infrared spectroscopy, an accumulation of oxygen-containing groups in polyethylene with sludge was shown in comparison with pure polyethylene after climatic tests. The catalytic effect of two metal slurries on the oxidative destruction of polyethylene was shown. [ABSTRACT FROM AUTHOR]