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Hierarchical ZSM-5 (Z1) were synthesized via a simple hydrothermal activation-crystallization method using silica sol and sodium aluminate as raw materials without adding any organic ammonium template. Based on the above synthesis method, sucrose, lignin and microcrystalline cellulose were added as mesoporous template to produce three hierarchical ZSM-5 (SZ，LZ and CEZ) respectively・ Further catalytic co-cracking of cellulose and low density polyethylene (LDPE) was carried out to investigate the effect of reaction temperature, catalyst acidity and pore size on the distribution of cracked products・ The highest yield of BTX (benzene, toluene and xylene) (21.6%) was obtained at 550 °C over Z1 for cocracking of cellulose/LDPE at 450 ~600 °C. Co-cracking experiments were carried out under the optimized temperature of 550 °C using different catalysts・ The CEZ-10 obtained the highest yield of BTX (26.1%) and good coke・resistance・ Compared to separately cracking of LDPE，co-cracking yield a higher BTX increased by 8.3% over CEZ-10. The results indicate that catalytic co-cracking of cellulose and LDPE contributes to the generation of BTX. [ABSTRACT FROM AUTHOR]

Plastic films have been widely adopted to improve plant growth in agriculture, covering soil temperature, evaporation reduction, and water conservation in the soil. The most extensively-used materials are polyethylenes (PEs) for agricultural mulching applications, due to their excellent tensile strength and resistance to degradation, such as the low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and copolymer poly (ethylene-vinyl acetate) (EVA). However, conventional film is made of polyethylene, leading to serious "White Pollution". Therefore, degradable materials can be expected to improve the polluted environment. Among them, crop straw can serve as the biggest renewable material with a variety of sources on the earth. Particularly, film mulching can be one of the most important approaches for the growth of crops. Normally, the degradable mulch film is commonly composed of biobased materials that rely on the biodegradable effects of sunlight (ultraviolet rays) and soil microorganisms. Furthermore, the biodegradable mulch film can be decomposed into carbon dioxide, water, and minerals, indicating a friendly environment. Moreover, the degradation rate of biodegradable films is influenced by the chemical components of the polymers. Crop straw can be obtained from corn, rice, wheat, sorghum, soybean, or sugar cane, indicating an abundant source of biomaterials. For instance, 700 million tons of various types of crop straw have been generated each year in China. Many attempts have been made to manufacture wood-based composites with agricultural residues, such as straw. Crop straw is an abundant agricultural residue with higher ash content, leading to the potential additional application as fodder. This study aims to improve the comprehensive utilization rate of crop straw. The straw film was made of rice straw by the in-situ polymerization, and tested as the ridge mulch for the crops. The results demonstrate that the mechanical properties of the straw fiber film were significantly enhanced by the modification. XRD results show that the crystallinity index of the modified film increased to 64.42% (raw film=38.11%). The enhancement in the crystallinity of the straw fiber film can be attributed to the functional additives, which penetrated into the amorphous region of cellulose. Microfibriles were obtained in the amorphous region, particularly close to the crystalline region, resulting in an increase in the width of the crystalline region of cell wall cellulose microfibril. The contact angle of the modified mulching film increased from 95.35° to 118.43°. Thermogravimetric (TG) analysis results indicated that the thermal stability of the modified film was improved after treatment. Moreover, the different chemical bonds in the unmodified and modified films revealed the chemical cross-linking between the film fibers and modifier after FTIR analysis. XPS analysis showed that there was an increase in the atomic concentration ratio of oxygen and carbon in the straw fiber base membrane after modification, indicating that the chemical cross-linking reaction between the modifier and the mulch fiber resulted in the increase of oxygen-containing functional groups. SEM-EDXA indicated that the modifier was uniformly dispersed in the fiber film, indicating an improvement in the mechanical properties. The experiment of tobacco mulch showed that the straw fiber base membrane improved the overall level of tobacco planting. Overall, the superior properties of the modified straw fiber film can make great potential for agricultural application. [ABSTRACT FROM AUTHOR]

The use of natural fibers (NF) as reinforcement in polymer composites have been an interesting option to improve their mechanical properties and to decrease production costs since several crops can produce large amounts of NF with low cost. This is particularly attractive for polymer waste recycling that depends of the production of cheap materials to be economically viable. Elephant grass (Pennisetum purpureum schum) is a tropical climate plant of fast growth with high potential for production of NF. However, studies on the use of P. purpureum fibers as reinforcement in polymers, mainly for recycled polymers, have been restricted. The aims of this study was to evaluate the action of the P. purpureum fibers on the properties of composites using matrix of low-density polyethylene waste (LDPE-w) as well as to verify the behavior of recycled polymer when submitted to the accelerated photochemical aging using UVA radiation. LDPE-w and LDPE-w composite with P. purpureum fibers (LDPE-composite) were analyzed at different aging times by tensile and impact tests, melt flow rate, scanning electron microscopy and Fourier transform infrared. It was verified that P. purpureum fibers induce defects in matrix of LDPE-w, decreasing the performance of mechanical properties. Similar effect also occurs when LDPE-w is submitted to the first hours of accelerated aging. On the other hand, effects of stabilization of the degradation on the polymer matrix can be attributed to the P. purpureum fibers at high aging times. Thus, P. purpureum presents high potential for use as reinforcement in recycled thermoplastic waste. [ABSTRACT FROM AUTHOR]

Filled biodegradable plastics can be prepared by mixing natural polymer materials with polymer. However, the addition of natural macromolecules leads to the instability of its mechanical properties, and the filled degradable plastics need further study. Modified LDPE/algae powder composites were prepared by using low density polyethylene (LDPE) as matrix, algae powder (spirulina) as filler, lubricant (polyethylene wax), compatibilizer (maleic anhydride grafted polyethylene) and plasticizer (glycerol) as additives. Its mechanical properties, thermal properties and biodegradability were tested. The results show that the modified LDPE/30% algae powder composite has the best mechanical properties, and the bending strength is 9.638 84 MPa, which is 15.7% higher than that of unmodified LDPE/30% algae powder. The highest degradation rate of modified LDPE/30% algae powder composite is 22.5% after 30 d of degradation under anaerobic conditions. Compared with pure LDPE material, the modified LDPE/30% algae powder composite has potential market application value as a biodegradable plastic. [ABSTRACT FROM AUTHOR]

With the combination of injection molding and gas pressure sintering, ceramic shaped parts with small size and high precision can be prepared in large quantities at low cost. In this paper, low density polyethylene (LDPE) and ethylene-vinyl acetate copolymer (EVA) were used as binders to prepare silicon nitride green bodies under injection temperature of 165 °C and injection pressure of 85 MPa. The complete silicon nitride injection molding process route was obtained by thermal degreasing process and sintering kinetics test. The effect of feedstock solid content on green body density, sintering density and Vickers hardness and the non-Newtonian index change of feedstock at 140 ~ 160 °C were studied. The results show that the optimum solid content of feedstock is 52. 42% (volume fraction). The density of silicon nitride injection green body prepared under this condition is 2. 10 g/cm³, the sintering density is 3. 23 g/cm³, and the Vickers hardness is (15. 24 ± 0. 34) GPa. The non-Newtonian index of feedstock is smallest at 160 °C, that is, the rheological of feedstock is the best at this temperature. [ABSTRACT FROM AUTHOR]

The main objective of this work is to validate an in-line micro-slit rheometer and a micro-extrusion line, both designed for the in-line monitoring and production of filaments for 3D printing using small amounts of material. The micro-filament extrusion line is first presented and its operational window is assessed. The throughputs ranged between 0.045 kg/h and 0.15 kg/h with a maximum 3% error and with a melt temperature control within 1 °C under the processing conditions tested for an average residence time of about 3 min. The rheological micro slit is then presented and assessed using low-density polyethylene (LDPE) and cyclic olefin copolymer (COC). The excellent matching between the in-line micro-rheological data and the data measured with off-line rotational and capillary rheometers validate the in-line micro-slit rheometer. However, it is shown that the COC does not follow the Cox–Merz rule. The COC filaments produced with the micro-extrusion line were successfully used in the 3D printing of specimens for tensile testing. The quality of both filaments (less than 6% variation in diameter along the filament's length) and printed specimens validated the whole micro-set-up, which was eventually used to deliver a rheological mapping of COC printability. [ABSTRACT FROM AUTHOR]

In the present study, the life cycle of two milk packaging containers (Polyethylene terephthalate PET and low-density polyethylene; LDPE) was assessed with an emphasis on different product-life scenarios in Iran. The functional unit was adjusted to work on one ton of plastic milk packaging containers. The system boundary included all life cycle stages, including resin production, packaging production, collection, transportation, and waste management (mechanical recycling, landfill, incineration). In the production sector, the resin was produced from raw materials and mechanical recycling was defined as producing granules from milk packaging containers. The granules obtained from recycling were used in the production of fruit baskets and disposable agricultural irrigation pipes. The first waste scenario included 10% recycling, 80% landfill, and 10% incineration. The second scenario consisted of 50% recycling, 20% landfill, and 30% incineration. The third scenario had 65% recycling, 10% landfill, and 25% incineration. Input data included using resources (water, raw materials), energy (electricity, fuels), and all emissions based on the function unit. The impact categories consisted of global warming, ozone depletion, fuel consumption, and toxicity to humans. SimaPro 9 software was run and the IMPACT + 2002 assessment method was employed to assess the environmental impact. According to the findings, the recycling process performed better than the landfill and incineration processes in all scenarios. The third scenario was determined as the most beneficent one in waste disposal of the two containers. In all effective categories, except air pollutants, the life cycle impact of PET was greater than that of LDPE. Furthermore, the life cycle impact of PET was greater than that of LDPE in all phases of the cycle except transportation. [ABSTRACT FROM AUTHOR]

The application of agricultural plastic products such as mulch, greenhouse covers, and silage films is increasing due to their economic benefits in providing an early and better‐quality harvest. However, mechanical abrasion of these plastic materials by soil particles could result in generation of microplastic (MP) pollutants that could harm soil organisms and impact food safety. This study aims to better understand the physicochemical mechanisms resulting in the fragmentation of low‐density polyethylene (LDPE). Herein, we used pellets and films to study the impacts of abrasive wear forces on their surface morphology variations and fragmentation behavior. An innovative laboratory approach was developed to abrade the plastic surface under controlled normal loadings and abrasion durations. The investigation of the plastics' surface morphology variations due to the abrasion process revealed microcutting as the dominant process at low normal force (4 N). However, a combination of microploughing and microcutting occurred for new LDPE films by increasing the normal force to 8 N. Despite the significant surface morphology variations of the new LDPE film due to the abrasion process; the water contact angle did not alter. Furthermore, the fragmentation behavior of photodegraded LDPE pellets and films was compared to the new plastics. The extent of MPs (3 µm < dp < 162 µm) generation due to fragmentation was studied using fluorescence microscopy imaging. The localized stress and strains at the contact sites of plastic and sand particles resulted in abrasion of the plastic surface. According to the results, the normal loadings and duration of abrasion played a significant role in the degree of fragmentation of plastics. Increasing the normal loading applied during the abrasion process from 2 to 8 N linearly increased the number of generated plastic fragments by more than five times for pellets and more than three times for film. Photodegradation significantly enhanced the extent of MPs fragmentation. Moreover, the limitations of this study and the implications for agricultural soil health were discussed. [ABSTRACT FROM AUTHOR]

In recent years, research into replacing synthetic fibers with natural fibers as reinforcements in thermoplastic composites has developed rapidly. The main objective of this work is to produce eco-friendly and cost-effective composite material. This material consists of natural fiber of sugarcane bagasse as the reinforcing component and thermoplastic polymer of low-density polyethylene as a matrix. The injection molding technique was used to produce the test samples. The fabricated composite contained 30 wt.% sugarcane bagasse. The effects of natural fiber sugarcane bagasse content, chemical treatment, and the addition of maleic anhydride as coupling agent on the composite degradation were studied. The degradation of sugarcane bagasse/low-density polyethylene composite under ultraviolet radiation and the thermal degradation were investigated. In addition, the amount of absorbance ultraviolet radiation by the fabricated composites was studied using ultraviolet-visible spectroscopy in the range from 200–800 nm. The effect of carbon black particles added to the fabricated composite on the degradation by ultraviolet exposure was also investigated. The results showed that the compatibilized sugarcane bagasse/low-density polyethylene composites at 3 wt.% maleic anhydride concentration revealed a higher decomposition temperature (466°C) than that of the uncompatibilized composites (460°C). This ensures that the thermal degradation temperature was improved by using the maleic anhydride coupling agent. Moreover, using the coupling agent showed significant resistance to degradation by ultraviolet exposure. Furthermore, the addition of 2.5 wt.% carbon black enabled more resistance to degradation by ultraviolet exposure. [ABSTRACT FROM AUTHOR]

Plastic is common material widely used all over the world. Plastic manufacturing crosses 150 million tonnes per year. Plastic is involved in all activities of human life. So, waste of plastics is also increasing gradually. This paper focuses on recycling waste plastic and making plastic composite construction material (PCCM) that include fine and coarse aggregate along with three types of waste plastic, i.e. high density polyethylene (HDPE), low density polyethylene, and polyethylene terephthalate. In this research, 27 mixes of plastic composite construction materials (PCCM) have been made, in which plastic is softened or melted up to a semi-liquid state with the help of used engine oil and mixed with aggregate. This material has been evaluated for various properties such as compressive strength, flexural strength, split tensile strength, density, and water absorption. HDPE with fine aggregate gives better results. [ABSTRACT FROM AUTHOR]

The present investigation reports the results of experiments related to the conversion of low-density polyethylene (LDPE) waste carry bags to fuel through an economic catalytic pyrolysis method in a batch reactor using zinc oxide (ZnO) as the catalyst. Plastics are highly beneficial for the day-to-day activities of human beings; however, their decomposition is limited due to their strong covalent bonding. Degradation of these big molecules into smaller ones or monomers has been attempted by several researchers in recent decades, with limited success. Pyrolysis is one of the ideas used to convert plastics, with the crowded structure of polymers, into fuel rather than small molecules. Among these plastics, LDPE is widely used as carry bags throughout the world, and, herein, the results of catalytic pyrolysis of the conversion of LDPE into fuel are reported. A compact laboratory-scale batch reactor, specially designed at our laboratory, was used to carry out the pyrolysis process. Different dosages of ZnO were used as a catalyst to carry out the pyrolysis at a specific temperature. The optimal dosage of ZnO for a 50 g waste LDPE batch was found to be 0.6 g to get the maximum oil yield. The yielded oil was analyzed chemically through Fourier transform infrared spectroscopy (FTIR) and a Reformulyzer M4 Hydrocarbon Group Type Analyzer. Evaluation of physical and chemical exergy along with exergetic efficiency of the process was carried out. The described experiments and the results represent a small but significant step toward curbing the menace of plastic solid wastes, which are degrading the environment and human life worryingly, and allowing them to be utilized for generating low-cost fuel for transportation and other applications. [ABSTRACT FROM AUTHOR]

Precise simulation of the topology structure of low‐density polyethylene (LDPE) chain is significant for product properties research. However, the chain structure symbolization methods in literature all rely on specially designed methods or temporary tricks, which are hard to understand and may induce some deviations in branch distribution prediction. To overcome this problem, a graph theory assisted Monte Carlo algorithm is developed for chain topology structure simulation of LDPE. The new symbolization method provides better accuracy and is much easy for code implementation and integration in other software. In detail, the average long chain branching predicted by this method is always smaller than that predicted by traditional methods, and much closer to the experimental results. Furthermore, the predicted topology structure information of LDPE chains can be provided as input data for molecular dynamics simulation to study the crystal process, and the predicted crystallinity and density also show good agreement with experiments. [ABSTRACT FROM AUTHOR]

The involvement of microorganisms in low-density polyethylene (LDPE) degradation is widely studied across the globe. Even though soil, landfills, and garbage dumps are reported to be promising niches for such organisms, recently the involvement of wood decay fungi in polyethylene degradation is highlighted. In light of this, 50 fungal samples isolated from decaying hardwoods were assessed for their wood degradation ability and for their depolymerization enzymatic activities. For the LDPE deterioration assay, 22 fungal isolates having wood decay ability and de-polymerization enzymatic activities were selected. Fungal cultures with LDPE sheets (2 cm x 10 cm x 37.5 μm) were incubated in the presence and in the absence of wood as the carbon source (C) for 45 days. Degradation was measured by weight loss, changes in tensile properties, reduction in contact angle, changes of functional groups in Fourier-transform infrared spectroscopy, Scanning electron microscopic imaging, and CO2 evolution by strum test. Among the isolates incubated in the absence of wood, Phlebiopsis flavidoalba out-performed the other fungal species showing the highest percentage of weight reduction (23.68 ± 0.34%), and the lowest contact angle (64.28° ± 5.01). Biodegradation of LDPE by P. flavidoalba was further supported by 46.79 ± 0.67% of the mass loss, and 3.07 ± 0.13% of CO2 emission (mg/L) in the strum test. The most striking feature of the experiment was that all the isolates showed elevated degradation of LDPE in the absence of wood than that in the presence of wood. It is clear that in the absence of a preferred C source, wood decay fungi thrive to utilize any available C source (LDPE in this case) showing the metabolic adaptability of fungi to survive under stressful conditions. A potential mechanism for LDPE degradation is also proposed. [ABSTRACT FROM AUTHOR]

Low-density polyethylene is one of the basic polymers used in medicine for a variety of purposes; so, the relevant improvements in functional properties are discussed here, making it safer to use as devices or implants during surgery or injury. The objective of the laboratory-prepared material was to study the antimicrobial and biocompatible properties of low-density polyethylene composites with 3 wt. % hybrid nanoclay filler. We found that the antimicrobial activity was mainly related to the filler, i.e., the hybrid type, where inorganic clay minerals, vermiculite or montmorillonite, were intercalated with organic chlorhexidine diacetate and subsequently decorated with Ca-deficient hydroxyapatite. After fusion of the hybrid nanofiller with polyethylene, intense exfoliation of the clay layers occurred. This phenomenon was confirmed by the analysis of the X-ray diffraction patterns of the composite, where the original basal peak of the clays decreased or completely disappeared, and the optimal distribution of the filler was observed using the transmission mode of light microscopy. Functional property testing showed that the composites have good antibacterial activity against Staphylococcus aureus, and the biocompatibility prediction demonstrated the formation of Ca- and P-containing particles through an in vitro experiment, thus applicable for medical use. [ABSTRACT FROM AUTHOR]

During laundering, synthetic textiles (polyester, polyamide, etc.) can release small fiber debris with a length of <5 mm. These are a type of microplastics (MPs), usually referred to as microfibers (MFs), which are considered high-concern pollutants due to their continuous and cumulative entrance into the environment. Currently, as far as we know, there are no feasible alternatives to remove them. In this work, four new and sustainable filtering systems are proposed to retain the MFs emitted from domestic washing machines. The filters contain a replaceable cartridge partially filled with recycled low-density polyethylene pellets. The four designed filtering systems of different sizes were tested in a household washing machine determining the retention efficiency of the MFs after several washing cycles. It was found that all four assessed filter arrangements have a good performance for retaining MFs from the washers' effluents. Filter F1 (diameter of 4 cm and a height of 30 cm) started retaining more than 50% of the MFs, at the 10th washing cycle, the retention climbed to 66%, while in the 20th washing cycle, its retention was greater than 80%. MFs retention was higher for filter F2 (diameter of 6.3 cm and a height of 41 cm), achieving a performance greater than 90% in the 20th washing cycle. Filter F3 was arranged by turning the F1 model flow upside down and the retention efficiency is higher compared with filter F1 values, reaching a retention efficiency of almost 100% in the 15th washing cycle. Finally, filter F4 arrangement was developed using the existing washing machine filter, obtaining better performance than the F1 and F2 filters, reaching efficiencies higher than 90% at the 20th washing cycle. In summary, depending on the arrangement, the microfiber retention efficiency was estimated between 52% and 86% in the 1st washing cycle and up to 83% to 99% in the 20th. Additionally, all arrangements demonstrated that the cartridges may last for more than 30 washing cycles before needing to be replaced. [ABSTRACT FROM AUTHOR]

In this study, antibacterial low-density polyethylene (LDPE) composites were prepared using a silver-based antibacterial agent (Ag agent) and compatibilizer (linear low-density polyethylene-g-maleic anhydride (LLDPE-g-MA)), and their thermal, mechanical, and antibacterial properties were examined. The crystallization temperatures of the compatibilizer/antibacterial composites were higher than those of the composites prepared without a compatibilizer. LDPE is a crystalline material, and the addition of LLDPE-g-MA reduced the PE content and enthalpy of the composite and improved the dispersibility of the Ag agent between the substrates. The antibacterial activity test revealed that the addition of the Ag agent and compatibilizer to LDPE composites enhanced their antibacterial effects. [ABSTRACT FROM AUTHOR]

Background: Oiti (Licania tomentosa [Benth.] Fritsch) is an option for urban forestation and rural environments that require shading by plants, so studying the plant environment to obtain quality seedlings is essential. The present study aimed to evaluate oiti seedlings in different protected environments with or without reflective material on a cultivation bench. Methods: The following protected environments were evaluated: an agricultural greenhouse covered with a low-density polyethylene film and a thermo-reflective screen with 42%/50% shading under the film; an agricultural screenhouse with an aluminized screen with 35% shading; an agricultural screenhouse with a black screen with 30% shading; and an agricultural screenhouse with a black screen with 18% shading. Production systems with and without photosynthetically active radiation-reflecting material (aluminized screen, Aluminet®) on the cultivation bench were assessed in each protected environment. Results: There was no interaction between the environmental factors; however, the environments influenced height, stem diameter, root dry matter, and total biometric relationships and growth rates. The reflective material did not improve the quality of oiti seedlings. The ratio of shoot and root dry matter was, on average, 71% for the shoots and 29% for the roots. The photosynthetically active radiation received by oiti seedlings ranged from 600 to 1,100 µmol m-2 s-1. Conclusions: The greenhouse with 42%/50% shading screen under the film and the black screen with 30% shading were the best environments for the formation of Licania tomentosa seedlings. The reflective material on the cultivation bench did not result in better quality oiti seedlings. [ABSTRACT FROM AUTHOR]

The increased use of bioplastics in the market has led to their presence in municipal solid waste streams alongside traditional fossil-based polymers, particularly low-density polyethylene (LDPE), which bioplastics often end up mixed with. This study aimed to assess the impact of cellulose acetate plasticized with triacetin (CAT) on the mechanical recycling of LDPE. LDPE–CAT blends with varying CAT content (0%, 1%, 5%, 7.5%, and 10% by weight) were prepared by melt extrusion and analyzed using scanning electron microscopy, Fourier-transform infrared spectroscopy, thermal analysis (thermogravimetric and differential scanning calorimetry), dynamic rheological measurements, and tensile tests. The results indicate that the presence of CAT does not significantly affect the chemical, thermal, and rheological properties of LDPE, and the addition of CAT at different levels does not promote LDPE degradation under typical processing conditions. However, the addition of CAT negatively impacts the processability and mechanical behavior of LDPE, resulting in the reduced quality of the recycled material. Thus, the presence of cellulose-based bioplastics in LDPE recycling streams should be avoided, and a specific sorting stream for bioplastics should be established. [ABSTRACT FROM AUTHOR]

In order to improve the environmental problems caused by the extensive use of plastics, this paper introduced a new strategy to add and modify the physical structure, which could not only reduce the use of plastics, but also improve the mechanical properties of bamboo plastic composites. In this work, the bamboo-woven structure was introduced into the bamboo fiber/low density polyethylene (LDPE) composites to enhance the mechanical properties. Besides, to enhance the interfacial compatibility, maleic anhydride (MA) and polyvinyl alcohol (PVA) were used to modify LDPE and bamboo-woven structure, respectively. The mechanical properties of the prepared PVA-bamboo-woven structure/bamboo fiber/MA-LDPE composites were greatly improved. The bamboo plastic composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, water contact angle (WCA) test and mechanical property test. The results showed that the bamboo-woven structure/bamboo fiber/MA-LDPE composite has superior properties at 45% bamboo fiber content. The tensile strength reached to 33.842 MPa, which was increased by 65.01% compared to the bamboo fiber/MA-LDPE composites, and the bending strength reached to 36.6585 MPa increased by 81.46% in relation to the bamboo fiber/MA-LDPE composites. In addition, even a large number of hydrophilic bamboo fibers and bamboo-woven structure were carried by the composites, a good hydrophobicity was still maintained and the WCA reached to 93.71°. The composites with excellent mechanical properties and hydrophobicity provided a reference for the use of bamboo fibers in environmentally friendly packaging materials. [ABSTRACT FROM AUTHOR]

Plastic waste elimination is more important for environmental pollution. Alternate fuel is essential for future IC engine applications because of fossil fuel availability. This study focuses on both challenges by creating combustion energy for direct injection CI engines from the wastes with lesser NOx emissions. Plastic wastes of low-density polyethylene (LDPE) have the most negligible recycling value based on their collection point of view from municipal wastes. Conversion of this LDPE plastic waste into alternate fuel for CI engines by pyrolysis will provide value for that waste. The combustion, emission, and performance of neat pyrolyzed oil of LDPE plastic wastes (POLPW) were studied with exhaust gas recirculation (EGR; 0%, 10%, and 20%) in a 1500 rpm 5.2 kW engine on different loads. 20% of EGR used POLPW fuel produced 31.63% of brake thermal efficiency and 62.28% reduction in NOx (596 ppm) than diesel at maximum load. Pyrolyzed oil of low-density polyethylene plastic wastes can be utilized as a 100% substitute fuel in CI engines with an EGR of 20%. This will provide alternate fuel and low-value plastic waste downcycling, initiating environmental pollution reduction. [Display omitted] • Using one time used plastic waste to generate combustion energy for engine. • Downcycling of low-density polyethylene environment waste by pyrolysis with 80% yield. • Neat pyrolyzed LDPE oil usage is possible with all loads in the engine. • Neat oil with 20% exhaust recirculation have 31.36% brake thermal efficiency. • Compared to diesel, 62.82% of NOx emissions were reduced. [ABSTRACT FROM AUTHOR]

Direct current (DC) power transmission systems have received great attention because it can easily integrate many types of renewable energies and have low energy loss in long-distance and large-capacity power transmission for electricity global sharing. Nanoparticles (NPs) have a positive effect on the insulation properties of polymers, but weak interaction between NPs and polymer matrix greatly decreases the effort of NPs on the enhancement of insulation properties, and thereby limits its engineering application. In this work, grafting strategy was used to link the modified NPs and polymer matrix to improve their interactions. Silica NPs (SiO2-NPs) were modified by 3-(methacrylyloxy) propyl-trimethoxysilane (MPS) to introduce highly active groups on the SiO2-NPs surface, followed by the pre-irradiated linear low-density polyethylene (LLDPE) being easily grafted onto the MPS modified SiO2-NPs (MPS-SiO2-NPs) in the melt blending process to obtain LLDPE-g-MPS-SiO2-NPs nanocomposites. Fourier-transform infrared (FT-IR) spectrum and X-ray photoelectron spectroscopy (XPS) confirm the successful incorporation of MPS into SiO2-NPs. Transmission electron microscopy (TEM) verifies that the modified SiO2-NPs exhibits more uniform distribution. The rheology result shows that the interaction between MPS-SiO2-NPs and LLDPE significantly improves. More importantly, the LLDPE-g-MPS-SiO2-NPs nanocomposites displays superior DC breakdown strength to that fabricated by conventional modification methods. When the addition of MPS-SiO2-NPs is 0.1 wt%, the highest DC breakdown strength values of 525 kV/mm and 372 kV/mm are obtained at 30 °C and 70 °C, respectively, and high DC breakdown strength can be well maintained in a wide loading range of NPs. [ABSTRACT FROM AUTHOR]

Purpose To compare small bowel distension and side effects between a diluted polyethylene glycol (PEG) solution and a low-density (0.1% w/v) barium sulfate suspension (LDBSS) for CT enterography (CTE) preparation. Materials and Methods Total 173 consecutive patients who underwent CTE were enrolled in this study. The LDBSS (1 L) was used in 50 patients, and the diluted iso-osmotic PEG solution (1 L) was used in 123 patients. Two blinded radiologists independently scored jejunal and ileal distensions on a 5-point scale. To compare side effects between the two groups, the patients reported whether they had immediate complications after the administration of the oral contrast media. Results For ileal and jejunal distension, the diluted PEG solution showed no difference from the LDBSS for either reader (ileum: reader 1, median, 4; 4, interquartile range, 3-4; 3-4, p = 0.997; reader 2, median, 4; 4, interquartile range, 3.3-4.0; 3-4, p = 0.064; jejunum: reader 1, median, 2; 2, interquartile range, 2-3; 2-3, p = 0.560; reader 2, median, 3; 2, interquartile range, 2-3; 2-3, p = 0.192). None of the patients complained of immediate complications following administration of either of the oral contrast media. Conclusion The diluted PEG solution showed comparable bowel distension compared to LDBSS and no immediate side effects; thus, it can be a useful alternative. [ABSTRACT FROM AUTHOR]

This study focuses on the development of low-density polyethylene matrix nanocomposite films for food packaging industry and aims at improving low-density polyethylene oxygen barrier properties while maintaining other relevant characteristics, such as processability, easy post-processing, optical and mechanical properties. low-density polyethylene nanocomposites, with 1 and 2.5 wt.% nanoclay (NC) and also compatibilized with 5 wt.% polyethylene grafted with maleic anhydride (PE-g-MA), were prepared and used to produce blown films. The nanocomposites were characterized in terms of their morphology, thermal, rheological, mechanical, barrier and optical properties, through scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), rheological measurements, tensile tests, water vapor transmission, oxygen permeability tests and spectrophotometry. The results demonstrated good NC dispersion in the polymer matrix and decreased oxygen permeability in the compatibilized nanocomposite films. All the other properties did not significantly change when compared to neat low-density polyethylene. Overall, the film properties were improved with the added nanoclay and PE-g-MA and, have potential for food packaging. [ABSTRACT FROM AUTHOR]

An effective non-covalent compatibilization method for graphite and low-density polyethylene is reported. To obtain this result, pyren-1-yl-stearate (P1S) was synthesized, characterized and mixed with graphite to provide a better dispersion in polyethylene matrix. The P1S improves the dispersion of carbon filler in polyethylene through non-covalent compatibilization: the pyrenyl group gives π−π stacking interactions with graphite and the stearyl chain provides van der Waals interaction with the polymer chain (specifically London dispersion forces). In this study, different P1S/graphite fillers were prepared with a ratio by weight of 90/10 and 50/50, respectively, by using manual and ball-milling mixing. Their stability, interaction and morphology were evaluated through TGA, RX, and SEM. Thermogravimetric analyses showed that ball-milling mixing is more effective than manual mixing in promoting π−π stacking interactions of molecules such as P1S ester containing an alkyl chain and aromatic rings. The role of ball milling is confirmed by X-ray diffraction measurements since it was possible to observe both exfoliation and intercalation phenomena when this technique was used to mix the P1S ester with graphite. SEM analyses of polyethylene containing 1% of the carbon fillers again highlighted the importance of ball milling to promote the interaction of the ester with graphite and, simultaneously, the importance of the alkyl chain in order to achieve polyethylene-graphite compatibilization. [ABSTRACT FROM AUTHOR]

Plastic waste is starting to threaten marine waters, especially microplastics. This micro-sized plastic can be consumed by marine biota. The accumulation of microplastics in the bodies of marine biota can threaten humans who consume them. The purpose of this study was to analyze the risk level of microplastic (polystyrene) exposure through the consumption of blood clams in the coastal area of Pao Village, Tarowang District, Jeneponto Regency. This type of research is a descriptive analysis with the Environmental Health Risk Analysis (EHRA) approach. The samples in this study were 30 respondents and 125 blood clams (anadara granosa). Data were obtained by interview using a questionnaire, identifying MPs in shells in the laboratory, and identifying polymer types using FTIR-spectroscopy. The results showed that 68 MPs of microplastics were found in blood clams (anadara granosa) samples. The dominant shapes were lines and blue. The types of polymers from the FTIR results are Polystyrene (PS), Low-density polyethylene (LDPE), Polyvinyl chloride (PVC), and Polyethylene (PE). The average non-carcinogenic daily intake (Intake) is 0.00012 mg/kg/day, the average risk level (RQ) is 0.0006, and the daily intake value is ≤0.2 (RfD Styrene), so it is said to be safe and the risk level value (RQ) ≤ 1, then categorized as the risk of exposure to MPs in humans through consumption of blood clams is still categorized as safe. The route of exposure to MPs in humans is not only through blood clams, so efforts to control the risk of exposure to MPs in humans are still needed. [ABSTRACT FROM AUTHOR]

Silica aerogels are viewed as potential thermal insulation materials because they are highly porous, adiabatic and lightweight. The lack of mechanical strength and hygroscopicity are the main barriers to their application. In order to tackle these issues, a direct sol-blending-gel combing freezing drying (SBG-FD) technique is used to create trimethylchlorosilane (TMCS)-modified natural polysaccharide-reinforced chitosan-silica aerogel (CS-T-SA) in this work. This brand-new CS-T-SA possesses three-dimensional network structure, and its thermal conductivity reaches 0.0360 W m−1 k−1 at 30 °C with bulk density as low as 0.0485 g cm−3 and volume shrinkage to a minimum of 5%. Hydrophobic modification with TMCS gives the composite aerogel a promisingly high hydrophobicity with the water contact angle of 135.1°. In comparison to conventional silica aerogels, the chitosan-silica aerogels exhibit improved mechanical characteristics, with no brittle rupture up to at least 80% strain and stress at 80% strain values of 0.285–0.486 MPa. Remarkably, aerogel monoliths can be machined and sculpted using tools. This demonstration to produce monolithic and machinable, mesoporous aerogels with low-density from bio-sourced, renewable and nontoxic precursors, combined with good thermal stability and hydrophobicity opens up new possibilities for biopolymer-silica aerogel applications and represents a significant approach toward the commercialization of biopolymer-silica aerogels. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • This study firstly provided detailed photograph and spectrum evidence on particle accumulation in thrombi. • A quantity of micoparticles including those from synthetic materials such as pigments and plastics were detected in thrombi. • Particles were all block-shaped and varied from 2.1 to 26.0 μm in size, among which 69% were smaller than 10 μm. Environmental microparticle is becoming a global pollutant and the entire population is increasingly exposed to the microparticles from artificial materials. The accumulation of microparticles including microplastics and its subsequent effects need to be investigated timely to keep sustainable development of human society. This study aimed to explore the accumulation of environmental particles in thrombus, the pathological structure in the blood circulation system. Patients receiving cardiovascular surgical operations were screened and twenty-six thrombi were collected, digested and filtered. Non-soluble microparticles were enriched on the filter membrane and then were analyzed and identified with Raman Spectrometer. The associations of particle status (presence or absence) or particle number in the thrombus and clinical indicators were examined. One strict quality control-particle detection system was designed to eliminate environmental contaminations. Among twenty-six thrombi, sixteen contained eighty-seven identified particles ranging from 2.1 to 26.0 μm in size. The number of microparticles in each thrombus ranged from one to fifteen with the median reaching five. All the particles found in thrombi were irregularly block-shaped. Totally, twenty-one phthalocyanine particles, one Hostasol-Green particle, and one low-density polyethylene microplastic, which were from synthetic materials, were identified in thrombi. The rest microparticles included iron compounds and metallic oxides. After the adjustment for potential confounders, a significantly positive association between microparticle number and blood platelet levels was detected (P < 0.01). This study provides the first photograph and Raman spectrum evidence of microparticles in thrombi. A large number of non-soluble particles including synthetic material microparticles could accumulate in arteries, suggesting that the risk of microparticle exposure was under-estimated and the re-evaluation of its health effects is urgently needed. There will be a series of reports on assessing the health effects of microparticle exposure in humans in the future and this research provided clues for the subsequent research. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastic (MP) contamination is a globally recognised issue in aquatic environments, and recently, there has been an increase in investigations focusing on lake contamination, revealing significant amounts of dispersed MPs. However, our understanding of the ingestion and effects of MPs on organisms living in lake ecosystems remains limited. This study aims to develop an effective protocol for assessing the ingestion of MPs by the talitrid amphipod Cryptorchestia garbinii, with the goal of verifying and evaluating the biological effects following ingestion. Individuals sampled from the shores of Lake Albano were exposed to four different polymers, namely low-density polyethylene (PE), polyethylene terephthalate (PET), polyester (PES), and polypropylene (PP), under laboratory conditions. To deliver MPs through the diet, we decided to employ DECOTABs (DEcomposition and COnsumption TABlets) which have been successfully used as a food source in aquatic toxicity tests. At the end of the experiments, we employed the solvatochromic and fluorescent dye Nile red to detect and quantify the MPs present in the digestive tube contents of the animals. The results clearly demonstrate the ingestion of the supplied polymers through the tabs, validating this method of exposure as effective. Furthermore, the measurement of glucose, glycogen, and lipid levels reveals that within 24 h of ingestion, MPs had an impact on the macromolecules involved in the energy metabolism of C. garbinii. This research underscores the suitability of this species as a model organism for studying MP uptake and its effects. [ABSTRACT FROM AUTHOR]

Plastic waste generated from the widespread use of low-density polyethylene (LDPE) has raised significant environmental concerns due to its slow degradation. This review article explores the progress in LDPE nanocomposites for photodegradation, emphasizing strategies, mechanisms, and applications. Incorporating inorganic nanoparticles like titanium dioxide (TiO2), zinc oxide (ZnO), and iron oxide (Fe2O3) into LDPE has been examined to enhance its properties and biodegradability. These nanoparticles strengthen LDPE's mechanical, thermal, and barrier characteristics, thereby improving its overall performance. Various techniques have been employed to optimize the concentration and size of nanoparticles to attain the desired properties. Photodegradation, employing sunlight to break down LDPE into smaller fragments, has effectively decomposed plastic waste and reduced its environmental impact. Artificial UV light sources and additives like sensitizers and biological agents such as enzymes and microorganisms can enhance photodegradation. The incorporation of inorganic nanoparticles in LDPE significantly improves its properties and biodegradability. Research into LDPE nanocomposites for their degradation under sunlight shows potential in addressing the environmental challenges caused by plastic waste. This advancement opens the door to a wide range of applications for LDPE nanocomposites, offering a sustainable alternative to traditional plastics. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are an emerging environmental health concern due to their widespread occurrence in food sources such as fish, meat, chicken, honey, sugar, salt, tea and drinking water, thereby posing possible risks to human health. This study aimed to observe the existence of MPs in the crop and gizzard of the farm chicken, a significant food source in Pakistan. Twenty-four chicken samples were taken from eight poultry farms across Punjab, Pakistan. A total of 1227 MP particles were found from 24 samples (crop and gizzards) originating from the 8 poultry farms. In all, 429 MP particles were found in 24 chicken crops, with a mean of 17.8 ± 12.1 MPs/crop. In contrast, 798 MP particles were found in 24 chicken gizzards, with a mean of 33.25 ± 17.8 MPs/gizzard. Comparatively larger particles, ranging between 300–500 µm, were more abundant (63%) than other considered sizes (300–150 µm [21%] and 150–50 µm [16%]). Additionally, fragments were the dominant type of shape in both sample types (crop [64%] and gizzard [53%]). The predominant colours of particles extracted from gizzards and crops were yellow (32%) and red (32%), respectively. Chemical characterisation of these particles detected four types of polymers: polyvinyl chloride (PVC) at 51.2%, followed by low-density polyethylene (LDPE) at 30.7%, polystyrene (PS) at 13.6% and polypropylene homopolymer (PPH) at 4.5%. In conclusion, we provide evidence for MPs in the gizzards and crops of farmed chickens which may originate from contaminated poultry feed. Only a few studies have been reported globally to assess MPs ingestion in chickens. The current study is the first report from Pakistan. It could be a valuable addition to support MPs literature to establish a relationship between MPs contamination and intake through the food chain. [ABSTRACT FROM AUTHOR]

Pyrolysis has been proven as a method to reduce plastic waste and produce useful products, especially liquid fuels. However, plastic pyrolysis also produces gases and char as by-products which are being investigated for useful products. Therefore, our present study aims to investigate the char characteristics of plastic pyrolysis for further use as briquettes. Seven samples of char byproducts from the pyrolysis process of low-density polyethylene (LDPE) plastic at various reaction temperatures and catalyst types were studied. The proximate test is used to determine the properties of char such as moisture content, ash, volatile matter, and fixed carbon while the bomb calorimeter is used to determine the calorific value. Briquettes are formed by mixing 4 grams of char and 0.5-1 gram of binder (1% starch and 90% water). The briquettes were formed into solid cylinders with a diameter of 1.75 cm and formed with a pressure of 10 kg/cm2. Furthermore, the impact resistance index (IRI) was used to test the performance of the briquettes and showed an IRI value between 100 and 200. However, of the seven char samples tested, three of them were impossible to process into briquettes because they melted during the combustion test. [ABSTRACT FROM AUTHOR]

Plastic is one of the main pollutant sources that are difficult to decompose and then carried into the ocean and fragmented into smaller parts (microplastics) due to UV radiation and water currents. Their small size means that microplastics are often ingested by aquatic organisms, such as fish. This research aimed to determine the presence, abundance, and types of microplastics in the digestive tract of four dominant fishes landed at Lengkong Fish Auction Point, Cilacap, Central Java, i.e. threadfin (Eleutheronema tetradactylum), mackerel (Rastrelliger sp.), threadfin bream (Nemipterus japonicus), and hairtail (Trichiurus lepturus). We found microplastics in the digestive tract of four selected fishes with a frequency of occurrence of 100%. The concentration of microplastics in fish digestive tracts is relatively high, with a value range of 12 ±2.86 to 28.33 ±8.11 particles·ind.-1. Microplastics were found in films, fibres, fragments, and granule shape types with various colours: brown, purple, blue, black, green, transparent, and yellow. The polymers found were polystyrene (PS), nylon, acrylonitrile butadiene styrene (ABS), polyurethane (PU), polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE). The present study provides baseline data for microplastics contamination in commercial fish species landed at Lengkong Fish Auction Point, Cilacap, Central Java, Indonesia. The fact that we discovered PU, the most harmful polymer, piques our attention. [ABSTRACT FROM AUTHOR]

Covering material is an important tool to reduce damage from extreme weather events, especially in horticultural species. However, physiological and biochemical responses to covering material are still limited in woody plants. Thus, this study aimed to evaluate covering material effects on photosynthetic and antioxidant performance in blueberry cv. Legacy to high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) covering treatments under field conditions during two consecutive seasons. Our results showed that net photosynthesis (Pn) was reduced in LDPE compared to uncovered treatment during the first season. Interestingly, Pn increased 10% in HDPE compared to uncovered and LDPE treatments. Stomatal conductance (gs) was not affected by covering material; meanwhile, the transpiration (E) only showed a 22% increment in LDPE. HDPE exhibited the highest chlorophyll a in the 2018/2019 season compared to the uncovering treatment, as well as chlorophyll b and chlorophyll a/b ratio, but during the 2017/2018 season. A tendency to decrease chlorophyll a level in uncovered plants and LDPE treatment was observed during the 2018/2019 season. Antioxidant activity showed no differences among covering materials. By contrast, phenols increased in LDPE treatment followed by control plants, showing HDPE treatment the lower values during 2018/2019. In conclusion, this study demonstrated that blueberry plants subjected to HDPE treatment showed better Pn and chlorophyll levels than uncovered and LDPE treatments, which could be associated with the diffuse transmittance in HDPE, whereas a high E and phenols were observed in LDPE, whereas intrinsic water use efficiency was lower, which is related to high direct transmittance in this covering material during the summer season. Core Ideas: High‐density polyethylene (HDPE) showed better Pn and chlorophyll levels than uncovered and low‐density polyethylene (LDPE) treatment.High transpiration and phenols concentration were observed in LDPE, related to high direct transmittance in this covering material.A low WUEint were observed in LDPE compared to HDPE, particularly during the second season. [ABSTRACT FROM AUTHOR]

The thermal and rheological behavior of blends of a Fischer–Tropsch (F‐T) wax with linear low‐density polyethylene (LLDPE) were investigated by differential scanning calorimetry and cone‐and‐plate rheometry. F‐T wax is used as a possible low‐cost processing aid alternative for LLDPE masterbatch applications. The melting‐ and crystallization thermograms indicated a two‐phase solid‐state morphology and full compatibility in the fully molten material. Both the high‐melting and low‐melting phase contained co‐crystalized wax and polymer. Rheological data of F‐T wax‐LLDPE blends over the full composition range was also obtained. The zero‐shear viscosity data was adequately predicted by the Friedman and Porter mixing rule: η=wpηp1/α+wwηw1/αα with α = 3.4. This implies that the melt viscosity is dominated by the effects of polymer chain entanglement and that the main consequence of adding the wax is to reduce the concentration of the polymer present. The complex viscosity also fitted this model albeit with α = 4.81. All Han plots, that is, plots of the logarithm of the storage modulus (G') against the logarithm of the loss modulus (G"), were linear. Within the experimental uncertainty, they were essentially unaffected by variations in blend composition, temperature and the applied angular frequency. Additionally, Cole–Cole plots were also in agreement that wax‐LLDPE blends are miscible at melt state. This supports full miscibility of the F‐T wax‐LLDPE blend system down to temperatures as low as 120°C. [ABSTRACT FROM AUTHOR]

Polyethylene is a versatile polymer suitable for a large variety of flexible and rigid packaging applications. Its mechanical and rheological properties can be tuned across a wide range by controlling its molecular architecture, such as the amount and distribution of olefinic comonomers (short chain branching), long chain branching, and molecular weight distribution. Linear low‐density polyethylene (LLDPE) is known for its high toughness which enables downgauged film structures and low‐density polyethylene (LDPE) is known for its excellent shear thinning and melt strength which enables enhanced processability and high throughput, such as on blown film lines. In order to obtain a balance of toughness and processability on films produced on blown film lines, blends of LLDPE and LDPE are commonly used. In this paper, we describe additive‐based approaches, including a new product, DOWLEX™ (TM = trademark of the Dow Chemical Company ("Dow") or an affiliated company of Dow) GM AX01, which enhances melt strength and other rheological properties of polyethylene, enabling fabrication of films with lower LDPE content while still maintaining excellent rheological properties and higher toughness versus conventional LLDPE/LDPE blends. The higher toughness enables downgauging without loss of mechanical properties, which in turn reduces consumption of polymer resulting in a more sustainable solution. [ABSTRACT FROM AUTHOR]

Τhe replacement of food packaging additives and preservatives with bio-based antioxidant/antibacterial compounds has been a common practice in recent years following the trend of bioeconomy and nanotechnology. Such bio-additives are often enclosed in nanocarriers for a controlled release process. Following this trend in this work, a thymol (TO)-rich activated carbon (AC) nanohybrid was prepared and characterized physicochemically with various techniques. This TO@AC nanohybrid, along with the pure activated carbon, was extruded with low-density polyethylene (LDPE) to develop novel active packaging films. The codenames used in this paper were LDPE/xTO@AC and LDPE/xAC for the nanohybrid and the pure activated carbon, respectively. X-ray diffractometry, Fourier-transform infrared spectroscopy, and scanning electron microscopy measurements showed high dispersity of both the TO@AC nanohybrid and the pure AC in the LDPE matrix, resulting in enhanced mechanical properties. The active film with 15 wt.% of the TO@AC nanohybrid (LDPE/15TO@AC) exhibited a 230% higher water/vapor barrier and 1928% lower oxygen permeability than the pure LDPE film. For this active film, the highest antioxidant activity referred to the DPPH assay (44.4%), the lowest thymol release rate (k2 ≈ 1.5 s−1), and the highest antibacterial activity were recorded, resulting in a 2-day extension of fresh pork fillets' shelf-life. [ABSTRACT FROM AUTHOR]

Microplastics have been studied on biota and other environmental domains, such as soils. Despite the importance of groundwater as a resource for millions of people worldwide as drinking water and personal hygiene, domestic, agricultural, mining, and industrial purposes, there are very few studies concerning microplastics in this domain around the world. We present the first study in Latin America addressing this topic. Six capped boreholes were analyzed in terms of abundance, concentration, and chemical characterization, at three different depths, from a coastal aquifer in Northwest Mexico. This aquifer is highly permeable and affected by anthropogenic activities. A total of 330 microplastics were found in the eighteen samples. In terms of concentration, the interval ranged from 10 to 34 particles/L, with an average of 18.3 particles/L. Four synthetic polymers were identified: isotactic polypropylene (iPP), hydroxyethylcellulose (HEC), carboxylated polyvinyl chloride (PVC), and low-density polyethylene (LDPE); with iPP being the most abundant (55.8%) in each borehole. Agriculture activities and septic outflows are considered the potential regional sources of these contaminants into the aquifer. Three possible transport pathways to the aquifer are suggested: (1) marine intrusion, (2) marsh intrusion, and (3) infiltration through the soil. More research about the occurrence, concentration, and distribution of the different kinds of microplastics in groundwater is needed to have a better understanding of the behavior and health risks to organisms, including human beings. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel bio‐based flame retardant, MHPA, was synthesized with magnesium hydroxide (MH) and phytic acid (PA) and was added to low‐density polyethylene (LDPE) with melamine cyanurate (MCA) to investigate the flame retardant, mechanical property and thermal stability of the LDPE composites. The limit oxygen index (LOI) and cone calorimeter test (CCT) results showed that the combination of MHPA and MCA can increase the LOI of LDPE composite to 21.6%, and its peak of heat release rate (pHRR), total heat release (THR) and total smoke production (TSP) values reduced by 46.8%, 20%, and 31.6% respectively compared with pure LDPE, while the residue after CCT was increased to 24.4%. Moreover, the addition of MCA can effectively improve the thermal stability of LDPE/MHPA composites and suppress their early decomposition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pyrolysis of virgin and LDPE and PP wastes was performed in a pilot setup. • GC × GC was applied to identify and quantify the composition of the pyrolysis oils. • Identification of optimal temperature and pressure for pyrolysis. • The formation of preferentially propylene oligomers during PP pyrolysis. • Plastic contaminations such as PVC and biomass intensify the coke formation. Due to the complexity and diversity of polyolefinic plastic waste streams and the inherent non-selective nature of the pyrolysis chemistry, the chemical decomposition of plastic waste is still not fully understood. Accurate data of feedstock and products that also consider impurities is, in this context, quite scarce. Therefore this work focuses on the thermochemical recycling via pyrolysis of different virgin and contaminated waste-derived polyolefin feedstocks (i.e., low-density polyethylene (LDPE), polypropylene (PP) as main components), along with an investigation of the decomposition mechanisms based on the detailed composition of the pyrolysis oils. Crucial in this work is the detailed chemical analysis of the resulting pyrolysis oils by comprehensive two-dimensional gas chromatography (GC × GC) and ICP-OES, among others. Different feedstocks were pyrolyzed at a temperature range of 430–490 °C and at pressures between 0.1 and 2 bar in a continuous pilot-scale pyrolysis unit. At the lowest pressure, the pyrolysis oil yield of the studied polyolefins reached up to 95 wt%. The pyrolysis oil consists of primarily α-olefins (37–42 %) and n -paraffins (32–35 %) for LDPE pyrolysis, while isoolefins (mostly C 9 and C 15) and diolefins accounted for 84–91 % of the PP-based pyrolysis oils. The post-consumer waste feedstocks led to significantly less pyrolysis oil yields and more char formation compared to their virgin equivalents. It was found that plastic aging, polyvinyl chloride (PVC) (3 wt%), and metal contamination were the main causes of char formation during the pyrolysis of polyolefin waste (4.9 wt%). [ABSTRACT FROM AUTHOR]

Breathable films were prepared based on linear low-density polyethylene (LLDPE), calcium carbonate (CaCO3), and aluminum (Al; 0, 2, 4, and 8 wt.%) using extrusion molding at a pilot scale. These films must generally be able to transmit moist vapor through pores (breathability) while maintaining a barrier to liquids; this was accomplished using properly formulated composites containing spherical CaCO3 fillers. The presence of LLDPE and CaCO3 was confirmed by X-ray diffraction characterization. Fourier-transform infrared spectroscopy results revealed the formation of Al/LLDPE/CaCO3 composite films. The melting and crystallization behaviors of the Al/LLDPE/CaCO3 composite films were investigated using differential scanning calorimetry. Thermogravimetric analysis results show that the prepared composites exhibited high thermal stability up to 350 °C. Moreover, the results demonstrate that surface morphology and breathability were both influenced by the presence of various Al contents, and their mechanical properties improved with increasing Al concentration. In addition, the results show that the thermal insulation capacity of the films increased after the addition of Al. The composite with 8 wt.% Al showed the highest thermal insulation capacity (34.6%), indicating a new approach to transform composite films into novel advanced materials for use in the fields of wooden house wrapping, electronics, and packaging. [ABSTRACT FROM AUTHOR]

Low density Polyethylene (LDPE) in various forms has become a part of life. Its accretion due to non degradable nature is concern, endangering life on earth. Amongst various methods of LDPE disposal bioremediation is regarded as ecofriendly & widely accepted. Current investigation was an attempt to isolate potent PE degrading fungus from municipal landfill soils of Bhopal, India loaded with plastic waste.16 fungal isolates were recorded from the site; PE deteriorating fungus was screened using mineral salt agar medium amended with 3% LDPE powder as sole carbon source. The isolate Penicillium citrinum showed fast fungal colony growth in screening medium was selected for biodegradation study. P.citrinum showed 38.82 ± 1.08% weight loss of untreated LDPE pieces; to improve the degradation capacity nitric acid pretreatment was performed; biodegradation was significantly stimulated by 47.22 ± 2.04% after it's pretreatment. Laccase, lipase, esterase & manganese peroxidase activities were assayed by spectrophotometer. LDPE biodegradation was analyzed by weight loss %, change in pH during fungal growth, field emission scanning electron microscopy (FE-SEM), fourier transform infrared spectroscopy (FTIR) & thermogravimetric analysis (TGA). FTIR spectra showed appearance of new functional groups assigned to hydrocarbon biodegradation, confirming enzymatic role in process. Changes in FTIR spectra of LDPE samples (untreated & pretreated) before & after biodegradation & surface changes in the biodegraded LDPE (indicated from FE-SEM) confirmed depolymerization of LDPE. Further changes in thermal decomposition rates of biodegraded samples in comparison to control, validate biodegradation. This is the first report signifying high competence of P.citrinum in LDPE degradation without prior pretreatment. [ABSTRACT FROM AUTHOR]

Background: Plastic is one of the most widely used materials worldwide in various fields, including packaging and agriculture. Its large quantities require proper disposal and for this reason more and more attention is paid to the issue of degrading plastic. Thanks to the production of non-specific enzymes, fungi are able to attack complex and recalcitrant xenobiotics such as plastics. In recent years, several spectroscopic methods were used to study the plastic degradation ability of different fungal species. Among these, Fourier transform infrared (FT-IR) and FT-Raman spectroscopy techniques are the most used. Surface-enhanced Raman scattering (SERS) spectroscopy is a powerful technique which uses metal nanoparticles (NPs) to enhance the Raman signal of molecules adsorbed on the NPs surface. In this work, the isolation of different fungi from field-collected plastic debris and the ability of these isolates to growth and colonizing the low-density polyethylene (LDPE) were explored by using scanning electron microscope (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and SERS spectroscopies. Results: Forty-seven fungal isolates belonging to 10 genera were obtained; among them only 11 were able to grow and colonize the LDPE film. However, after 90 days trial, only one isolate of Cladosporium cladosporioides (Clc/1) was able to carry out the initial degradation of the LDPE film. In particular, based on SEM observations, small cavities and depressed areas of circular shape were visible in the treated samples. Additionally, ATR-FTIR, normal Raman and SERS analyses supported the structural changes observed via SEM. Notably, ATR-FTIR and normal Raman spectra showed a significant decrease in the relative intensity of the methylene group bands. Similarly, the SERS spectra of LDPE after the fungal attack, confirmed the decrease of methylene groups bands and the appearance of other bands referring to LDPE polyphenolic admixtures. Conclusions: These results suggest that Cladosporium cladosporioides Clc/1 is able to carry out an initial degradation of LDPE. Moreover, combining ATR-FTIR, Raman and SERS spectroscopies with SEM observations, the early stages of LDPE degradation can be explored without any sample pretreatment. [ABSTRACT FROM AUTHOR]

Chemically recyclable polymers that can depolymerize into their constituent monomers are attractive candidates to replace non‐recyclable petroleum‐derived plastics. However, the physical properties and mechanical strengths of depolymerizable polymers are commonly insufficient for practical applications. Here we demonstrate that by proper ligand design and modification, aluminum complexes can catalyse stereoretentive ring‐opening polymerization of dithiolactone, yielding highly isotactic polythioesters with molar masses up to 45.5 kDa. This material can form crystalline stereocomplex with a Tm of 94.5 °C, and exhibits mechanical performances comparable to petroleum‐based low density polyethylene. Exposure of the polythioester to aluminum precatalyst used to synthesized it resulted in depolymerization to pristine chiral dithiolactone. Experimental and computational studies suggest that aluminum complexes have appropriate binding affinity with sulfide propagating species, thereby avoiding catalyst poisoning and minimizing epimerization reactions, which has not been accessible using other metal catalysts. Overall, aluminum catalysis provides access to performance‐advantaged stereoregular recyclable plastics as a promising alternative to petrochemical plastics, thus incentivizing improved plastic sustainability. [ABSTRACT FROM AUTHOR]

Interlining is a very important accessory in the garment industry and is used between two layers of fabric in the garment to support the appearance and stance of the garment. In fusible interlinings, petroleum‐based synthetic materials such as polyamide, polyester, high‐density polyethylene (HDPE), low‐density polyethylene (LDPE), and various copolymers are used as the bonding material. Since these polymers do not degrade over time in nature, they do not support environmentally friendly production. This study aimed to produce fully biodegradable (100%) fusible interlinings by using environmentally friendly biodegradable polymers instead of traditional ones and thus develop eco‐friendly garment with their help. Firstly, fusible interlinings were produced by coating three different polymers, one conventional (HDPE) and the other two biodegradable (PLA and PCL) on the cotton base fabric by knife coating technique. In the second stage, these fusible interlinings were applied to a 100% cotton shirting fabric, and their performance and biodegradability tests were performed. According to the results, it was revealed that these interlinings could be used in the production of completely biodegradable clothes. [ABSTRACT FROM AUTHOR]

A novel facilitated transport film was prepared by coating polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/aminated sodium lignosulfonate on TiO2/ZnO‐modified low‐density polyethylene (LDPE). Monoethanolamine (MEA), diethanolamine (DEA), ethylenediamine (EDA), diethylenetriamine (DETA), tetramethylpiperidine amine (TEMP), and acrylamide (AM) were selected to modify sodium lignosulfonate (Ls) for enhancing the selectivity and permeability of CO2/O2. The fabricated Ls were characterized by fourier transform infrared (FTIR), thermogravimetric test (TG), and scanning electron microscopy (SEM). The CO2 permeability and CO2/O2 selectivity were improved with the increase in the amount of amine groups. Compared with the addition of Ls modified by alcohol amine, the composite film has higher selectivity to CO2 after the addition of DETA‐Ls or TEMP‐Ls. The selectivity of the 1:3:3EDA/MEA‐Ls‐g‐AM composite film reached 13.7, and CO2 permeability increased by 5.54 times. The storage test also demonstrated that the composite films have better freshness retention ability. As a result, modified LDPE coated by PVA/PEG/aminated Ls has the potential as an active modified atmosphere packaging material. [ABSTRACT FROM AUTHOR]

An attempt was undertaken to elevate production of aromatic compounds through co‐upcycling of polystyrene (PS) and low‐density polyethylene (LDPE). The plastics samples were upcycled at 400 °C with catalyst H‐ZSM‐5. Compared to single plastic upcycling, co‐upcycling PS and LDPE demonstrated high advantages: lowered reaction temperature (390 °C), medium reaction rate (−1.35 %/°C), low yield to coke (1.62 % or less) and enhanced aromatics yield (42.9–43.5 %). In‐situ FTIR results demonstrated a constant production of aromatics in the 1 : 1 mixed plastic while in pure plastics, aromatic production quickly dropped. Compared to single PS upcycling, co‐upcycling PS with PE produced more monocyclic aromatic hydrocarbons (MAHs) at close to 43.0 % versus 32.5 % and less polycyclic aromatic hydrocarbons (PAHs) at 16.8–34.6 % versus 49.5 %. From these data, the synergy between PS and LDPE were confirmed and the mechanism in which they increased MAHs production was proposed. [ABSTRACT FROM AUTHOR]

The need to reach carbon neutrality as soon as possible has made the use of recycled materials widespread. However, the treatment of artificial marble waste powder (AMWP) containing unsaturated polyester is a very challenging task. This task can be accomplished by converting AMWP into new plastic composites. Such conversion is a cost-effective and eco-friendly way to recycle industrial waste. However, the lack of mechanical strength in composites and the low filling content of AMWP have been major obstacles to its practical application in structural and technical buildings. In this study, a composite of AMWP/linear low-density polyethylene (LLDPE) filled with a 70 wt% AMWP content was fabricated using maleic anhydride-grafted polyethylene as a compatibilizer (MAPE). The mechanical strength of the prepared composites is excellent (tensile strength ~18.45 MPa, impact strength ~51.6 kJ/m2), making them appropriate as useful building materials. Additionally, laser particle size analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and thermogravimetric analysis were used to examine the effects of maleic anhydride-grafted polyethylene on the mechanical properties of AMWP/LLDPE composites and its mechanism of action. Overall, this study offers a practical method for the low-cost recycling of industrial waste into high-performance composites. [ABSTRACT FROM AUTHOR]