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Polyvinyl Chloride (PVC) drives innovation across industries due to its properties like exceptional cost-performance ratio, versatility, and sustainability. PVC is the third most widely used plastic globally, surpassed only by [...]

The University of California, Berkeley, developed a new catalytic chemical process that has the potential to revolutionize plastic recycling by converting waste polyethylene (PE) and polypropylene (PP) into valuable monomers. [...]

Microplastics pollution represents a stringent global issue. Their accumulation in the aquatic environment remains complicated due to the abundance, distribution, and resulting environmental effects they induce. Recently, assessing the toxicity level on aquatic organisms has gained scientific interest. Due to the diverse types and sizes of polymers present in the environment, the detection and evaluation of their effects are still a challenging issue. Polyethylene (PE) and polystyrene (PS) are the most commonly used polymers and are therefore predominantly detected in both marine and freshwater aquatic environments. This paper aims to evaluate the effects of Red Nile-stained PE and PS, tested in different particle sizes (PE 40-48, 125, >125 µm, and PS 20, 200, 430 µm) on Daphnia magna, and highlight them through microscopic analysis. Acute toxicity tests conducted over a 48-hours exposure did not reveal significant toxicity effects in terms of mortalities compared to the controls. Red Nile staining allowed the visualization of the shapes and sizes of the tested microplastics and their entry pathways into the Daphnia bodies. PS of 20 µm size was detected in the digestive tract of Daphnia, indicating as primary pathway of entry into the body of aquatic organisms. No acute toxic effects were recorded as a result of direct exposure to PE and PS particles. However, sub lethal effects such as feeding and growth disturbances, which could affect organisms in the long term, are suspected.

The following is an investigation of structural changes in a stretched polyethylene foil using a Raman microscope with polarization-resolving optical components. Introduction Applying mechanical force to a polymer film aligns [...]

Forte Products is rotomolding the 13-foot polyethylene vessel IDEA 2023: Part seven of a series INTERNATIONAL DESIGN EXCELLENCE AWARDS Brunswick Corp. hopes to introduce pleasure boating to a new generation [...]

Synthesis and catalytic application of polymeric-based nanocomposites are important subjects among researchers due to their high lipophilicity as well as high chemical and mechanical stability. In the present work, a novel nanocomposite material involving ionic liquid and high-density polyethylene supported tungstate (PE/IL-WO4=) is synthesized, characterized and its catalytic application is investigated. The coacervation method was used to incorporate 1-methyl-3-octylimidazolium bromide ([MOIm] [Br]) ionic liquid in high-density polyethylene, resulting in a PE/IL composite. Subsequently, tungstate was anchored on PE/IL to give PE/IL-WO4= catalyst. The PXRD, FT-IR, EDX, TGA, and SEM analyses were used to characterize the PE/IL-WO4= composite. This material demonstrated high catalytic efficiency in the synthesis of bioactive tetrahydrobenzo[a]xanthen-11-ones under green conditions. The recoverability and leching tests were performed to investigate the stability and durability of the designed PE/IL-WO4= catalyst under applied conditions.

Innovative Thermoplastic Aerogel Filter Media for Air Filtration In a groundbreaking endeavor, mechanically recyclable thermoplastic materials were harnessed to craft lightweight and highly efficient aerogel filter media for air filtration. [...]

Objectives. To obtain and study the properties including degradability of polymer composite materials (PCM) based on low-density polyethylene (LDPE) obtained by introducing an environmentally friendly additive comprising an oxo-decomposing additive (ODA) based on an amphiphilic polymer-iron metal complex, which accelerates the process of polymer degradation.Methods. PCMs based on LDPE and ODA were produced by processing in laboratory extruders in the form of strands, granules, and films. Thermodynamic properties were determined by differential scanning calorimetry in the temperature range 20-130 °C. In order to assess the performance characteristics (physical and mechanical properties) of the PCM, tensile strength and elongation at break were determined. The biodegradability of PCM was evaluated by Sturm's method, with the biodegradation index being determined by the amount of CO2 gas released as a result of microorganism activity, as well as composting by placing the PCMs for six months in biohumus. Changes in physical and mechanical properties and water absorption of the films during storage were evaluated. The photochemical degradability of the PCM was determined by exposing it to ultraviolet radiation for 100 h (equivalent to approximately one year of exposure of the films under natural conditions). The appearance of the composite samples following removal from the biohumus was determined using an optical microscope with ×50 magnification in transmitted and reflected light.Results. Following biodegradation by composting, the physical and mechanical properties of PCMs decrease by an average of 40.6%. This is related to the structural changes that occur in composites during storage in biohumus, i.e., the formation of a looser structure due to the development of large clusters of microorganisms that affect the formation of microcracks. It leads to the stage of fragmentation of the polyethylene matrix and indicates the progress of biological degradation of composites. In this case, the water absorption of the composite samples was 63% after 96 h of exposure. The biodegradability index determined by the Sturm method after 28 days of bubbling had changed by 82%, indicating an intensive biodegradation process. Exposure to ultraviolet radiation for 96 h resulted in the complete destruction of the PCMs, which turned into small “flakes.” This method is the most effective for the degradation of LDPE- and ODA-based PCMs.Conclusions. According to the results of the study of ODA-containing PCMs based on an amphiphilic polymer-iron metal complex, the tested filler-modifier can be recommended for the production of PCMs offering an accelerated degradation period.

The paper analyzes the prospects of using a heat-accumulating material consisting of metallized polyethylene granules. X-ray diffraction analysis has been used to study the influence of the number of heating and cooling cycles of the heat-accumulating material on the change in the degree of crystallinity of polyethylene. It was shown that the proposed heat-accumulating material showed a low resistance and a significant decrease in the degree of crystallinity of polyethylene under the experimental conditions. The crystal structure of polyethylene did not change during cyclic heating and cooling. Grounded on the obtained experimental results, it was determined that a high degree of polyethylene crystallinity is being kept for 200–300 heating-cooling cycles.

The usage of cellulosic fibers as fillers for thermoplastics has generated great interest due to their numerous advantages and benefits compared to conventional fibers. This article examines a comparative study on the mechanical, thermal, and morphological properties of polypropylene/polyethylene (PP/PE)/cellulose (sugarcane bagasse (SCB) and softwood (SW)) blend composites prepared through melt compounding. The morphology of the obtained PP/PE/SCB and PP/PE/SW blend composites was investigated using scanning electron microscopy (SEM). The X-ray diffraction (XRD) analysis showed reduced crystallinity of the PP/PE blend after fiber interaction. Thermal results showed that the PP/PE/SW blend was more thermally stable compared to the PP/PE/SCB blend. Additionally, the onset temperature of main degradation decreased with th e incorporation of extracted celluloses. Differential scanning calorimetry (DSC) analysis revealed that the introduction of SCB or SW raw fiber and extracted celluloses did not significantly change the melting and crystallization behavior of the PP/PE blend. Dynamic mechanical analysis (DMA) revealed that the storage modulus of the PP/PE/SCB raw and PP/PE/SW raw materials were lower than their corresponding cellulose blend composites across the temperature range studied.

Low-density polyethylene (LDPE) is a staple in flexible plastic packaging, but ink contaminants pose challenges in mechanical recycling. You can also read Advancements in LDPE Synthesis and Recycling. Recycling is [...]

The plastics market demands sustainable alternatives to conventional fossil-based plastics. Bio-Polyethylene emerges as a promising solution, offering environmental advantages and maintaining performance. You can also read: Advancements in LDPE Synthesis [...]

Recycled plastics are making steady gains in major end-use markets. The latest example came on Oct. 26 when Revolution Co., of Little Rock, Ark., said it received a Letter of [...]

The crosslinking behavior of polyethylene (PE) determines its exceptional performance and application. In this study, we investigated the crosslinking behaviors of different PE resins through model simulation and rheological methods. Specifically, the mathematical equation of “S” model was established for PE resin. According to this equation, the optimal maximum gel content for high-density polyethylene (HDPE) was found to be around 85%. Moreover, the maximum crosslinking degrees for different PE resins depended largely on their density and molecular weight. The melt viscosities before crosslinking in PE resins were highly influenced by their melt index. The higher melt indexes resulted in the lower storage moduli, improving melt processability during processing. In addition, the crosslinking rates of PE resins were strongly influenced by peroxide concentration, independent of PE resin structures. For high molecular weight and low-density PE resins, they exhibited decreased ti values, increased A0 values, and decreased k6 values. However, there were no noticeable variations in the values of k2 and phi among different PE resins. All simulated modeling outcomes showed remarkable consistency with the experimental rheological data. These findings are of strong significance in the industrial manufacture of PE resin.

This work reports a facile fabrication method to modify exfoliated molybdenum disulfide (e-MoS2) nanosheets with magnetite nanoparticles with various size distribution. The obtained materials have been utilized as nanofillers of polyethylene to enhance its thermal properties and flame retardance. The incorporation of magnetite modified MoS2 nanosheets leads to the reduction of the peak heat release rate. The best thermal conductivity has been noticed for composites with e-MoS2/Fe3O4 with 2 wt. % of nanofillers. The lowest CO emission was observed for the PE/e-MoS2 composite containing also 2 wt. % of Fe3O4. All composites with exfoliated MoS2 exhibited greater thermal properties in respect to the pristine polyethylene.

Low-density polyethylene (LDPE), a pivotal plastic, is conventionally manufactured under extreme conditions, featuring robust aliphatic C-C bonds that hinder effective recycling. Despite its widespread use in packaging, merely 5% of [...]

Abstract Plastic waste is a serious environmental issue, and polyethylene (PE) is a significant component. The chemically inert nature of PE makes its recycling/upcycling process challenging. Thus, a novel method was demonstrated that enables the selective electrochemical functionalization and deconstruction of low‐density polyethylene (LDPE) by using low‐cost transition metal electrocatalysts at room temperature (23±2 °C) and low cell voltage (±1 V). Three different electrode and electrolyte combinations were studied for the oxidation of LDPE: copper metal/copper (II) ions, nickel metal/nickel (II) ions, and stainless steel/iron (II) and (III) ions. The copper and nickel electrode/electrolyte pairs showed a promising capability for oxidation and chain‐scission of LDPE. In contrast, the stainless‐steel and iron electrode/electrolyte pair showed no activity towards LDPE oxidation or depolymerization. The electrolysis of LDPE offers a new vista for the depolymerization and upcycling of plastics, further understanding of the process is needed.

In marine ecosystems, living organisms are continuously exposed to a cocktail of anthropogenic contaminants, such as microplastics (MPs) and endocrine disrupting compounds (EDCs). Being able to adsorb organic compounds, MPs would act as an additional contamination vector for aquatic organisms. To support this hypothesis, the sorption of six EDCs on MPs, including 4-t-butylphenol, 4-t-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, 17β-estradiol and its synthetic analog 17α-ethinylestradiol, has been investigated. These compounds belong to two contaminant families, alkylphenols and estrogens, included in the EU priority and watch lists of the Water Framework Directive. Sorption kinetics were studied onto polyethylene and polypropylene MPs under seawater conditions. MPs at a concentration of 0.400 mg mL−1 were added to a mix of the six EDCs, each at the individual concentration of 100 ng mL−1. The concentrations of contaminants were chosen to be close to environmental ones and comparable with those found in literature. The results demonstrated that the hydrophobicity of the compounds and the MP type are the two factors influencing the sorption capacity. The distribution coefficient (K d) of each compound was determined and compared to others found in the literature. A high affinity was demonstrated between 4-n-NP and PE, with a sorption reaching up to 2,200 ng mg−1.

The influence of intensity of the γ-irradiation on commercial high and low density polyethylene (LDPE and HDPE) granules (Kazanorgsintez PJSC, Kazan, Tatarstan, Russia) on their rheological and morphological properties at irradiation doses of 5 and 10 kGy was studied. Experiments in the oscillation mode revealed an increase in the dynamic moduli values with increasing radiation dose compared to the initial samples. At the same γ-irradiation doses, the HDPE samples compared to the LDPE ones showed the greatest changes in rheological properties, while the zero shear viscosity of HDPE increased by order of magnitude compared to the initial one at the irradiation dose of 10 kGy. Morphology analysis of supramolecular structures revealed an increase in cob-web-type structures for the irradiated sample in comparison with the initial sample, which may indicate the formation of branched structures under γ-irradiation.

Abstract Functional binders constitute a strategy to overcome several challenges that lithium‐sulfur (Li‐S) batteries are facing due to soluble reaction intermediates in the positive electrode. Poly (ethylene oxide) (PEO) and poly (vinylpyrrolidone) (PVP) are in this context a previously well‐explored binder mixture. Their ether and amide groups possess affinity to the dissolved sulfur species, which enhances the sulfur utilization and mitigates the parasitic redox shuttle. However, the immiscibility of PEO and PVP is a concern for electrode stability. Copolymers comprising ether and amide groups are thus promising candidates to improve the stability the system. Here, a series of poly (ethylene glycol‐block‐2‐ethyl‐2‐oxazoline) with various block lengths is synthesized and explored as binders in S/C composite electrodes in Li‐S cells. While the electrochemical analyses show that although the sulfur utilization and capacity retention of the tested electrodes are similar, the integrity of the as‐cast electrodes can play a key role for power capability.

Low density polyethylene is widely used in agricultural production. It is of low cost and able to significantly improve the quality of fruits. However, its decomposition under natural circumstances needs more than one hundred of years. If not removed in time, it is hazardous to the ecological environment and crops. Up to now, the removal techniques of polyethylene films are polluted, expensive, and difficult to employ. A novel method is proposed for in situ removal of polyethylene by an effective and environmental friendly technique with low cost. The Nb-modified SnO2 quantum dots are prepared for the efficient photocatalytic degradation of polyethylene under visible light. The green synthesis of the photocatalyst includes the procedures of hydrolysis, oxidation, and hydrothermal treatment in aqueous solution. The Nb-modified SnO2 has a band gap of 2.95 eV, which enhances its absorption of visible light. A degradation efficiency of 29% is obtained within 6 h under visible irradiation. The hydroxyl radicals (•OH) are main active species in the degradation process. The prepared Nb-SnO2 quantum dots demonstrate a promising application in the photocatalytic degradation of polyethylene, contributing a novel strategy for the in situ treatment of agricultural wastes.

A low-density polyethylene was hydrocracked to liquid hydrocarbons in autoclave reactors over catalysts containing Pt- and Al-modified MCM-48. Two kinds of Al-modified MCM-48 were synthesized for the reaction: Al-MCM-48 was synthesized using a sol–gel method by mixing Al(iso-OC3H7)3 with Si(OC2H5)4 and surfactant in a basic aqueous solution before hydrothermal synthesis, and Al/MCM-48 was synthesized using a post-modification method by grafting Al3+ ions on the surface of calcined Al/MCM-48. X-ray diffraction (XRD) patterns indicated that both Al-MCM-48 and Al/MCM-48 had a cubic mesoporous structure. The Brunauer–Emmett–Teller (BET) surface areas of Al-MCM-48 and Al/MCM-48 were larger than 1000 m2/g. 27Al Magic Angle Spinning-NMR (MAS NMR) indicated that Al3+ in Al-MCM-48 was located inside the framework of mesoporous silica, but Al3+ in Al/MCM-48 was located outside the framework of mesoporous silica. The results of ammonia temperature-programmed desorption (NH3-TPD) showed that the acidic strength of various samples was in the order of H-Y > Al/MCM-48 > Al-MCM-48 > MCM-48. After 4 MPa H2 was charged in the autoclave at room temperature, 1 wt % Pt/Al/MCM-48 catalyst showed a high yield of C9−C15 jet fuel range hydrocarbons of 85.9% in the hydrocracking of polyethylene at 573 K for 4 h. Compared with the reaction results of Pt/Al/MCM-48, the yield of light hydrocarbons (C1−C8) increased over Pt/H-Y, and the yield of heavy hydrocarbons (C16−C21) increased over Pt/Al-MCM-48 in the hydrocracking of polyethylene. The yield of C9−C15 jet fuel range hydrocarbons over the used catalyst did not decrease compared to the fresh catalyst in the hydrocracking of polyethylene to jet fuel range hydrocarbons over Pt/Al/MCM-48.

Sevenpack and Gerdau Graphene say new PE film marks a 'world first' Brazilian flexible polyethylene film producer Sevenpack has collaborated with nanotechnology firm Gerdau Graphene to commercialize what they claim [...]

Abstract In this work, different types of polyethylene (linear, spiral nanofibers and microspheres) were obtained via confined polymerization by a PPM‐supported Ziegler‐Natta catalyst. Firstly, the Ziegler‐Natta catalyst was chemical bonded inside the porous polymer microspheres (PPMs) supports with different pore diameter and supports size through chemical reaction. Then slightly and highly confined polymerization occurred in the PPM‐supported Ziegler‐Natta catalysts. SEM results illustrated that the slightly confined polymerization was easy to obtain linear and spiral nanofibers, and the nanofibers were observed in polyethylene catalyzed by PPMs‐1#/cat and PPMs‐2#/cat with low pore diameter (about 23 nm). Furthermore, the highly confined polymerization produced polyethylene microspheres, which obtained through other PPM‐supported Ziegler‐Natta catalysts with high pore diameter. In addition, high second melting point (Tm2: up to 143.3 °C) is a unique property of the polyethylene obtained by the PPM‐supported Ziegler‐Natta catalyst after removing the residue through physical treatment. The high Tm2 was ascribed to low surface free energy (σe), which was owing to the entanglement of polyethylene polymerized in the PPMs supports with interconnected multi‐modal pore structure.

A series of high-density polyethylene/Cloisite 20A/graphite nanocomposites were prepared via melt blending for the production of polymeric pipes for natural gas transfer. The microstructural, mechanical, thermal, electrical and barrier properties of prepared nanocomposites were investigated. An intercalated morphology was observed for prepared nanocomposites. Improved mechanical properties e.g. over 148 % increase in Young’s modulus were observed by incorporating the nanoparticles into the polyethylene matrix. The thermal analysis showed that the melting point of polyethylene was slightly increased by incorporating both fillers, i.e. Cloisite 20A and graphite in it, and the crystallinity was depended on the type of filler. The results showed that the MFI values decreased by incorporating the fillers into the polyethylene matrix and further decreases were observed by increasing the contents of the filler. It was also found that a considerable amount of electrical conductivity is created in graphite loaded nanocomposites. The natural gas permeability investigations revealed of more than 51 % decrease in the permeability by incorporating 5 wt.% of Cloisite 20A to the polyethylene. It was concluded that the prepared nanocomposites due to their enhanced mechanical, thermal and barrier properties along with the conductive nature are excellent materials to be used in the production of polymeric pipes in natural gas distribution and transportation networks.

After around 50 years of development, the key substance known as polyethylene has been extremely influential in a variety of industries. This paper investigates how polyethylene materials have been used in the domains of water, packaging, and medicine to advance contemporary society in order to comprehend the physical and chemical alterations that polyethylene undergoes after being subjected to long-term environmental variables (e.g., temperature, light, pressure, microbiological factors, etc.). For the safe operation of polyethylene materials, it has always been of the utmost importance to evaluate polyethylene’s service life effectively. This paper reviews some of the most common literature journals on the influence of environmental factors on the degradation process of polyethylene materials and describes methods for predicting the lifetime of degradable polyethylene materials using accelerated aging tests. The Arrhenius equation, the Ozawa–Flynn–Wall (OFW) method, the Friedman method, the Coats–Redfern method, the Kissinger method and Kissinger–Akahira–Sunose (KAS) method, Augis and Bennett’s method, and Advanced Isoconversional methods are all discussed, as well as the future development of polyethylene.

The objective of this study was to present a simple and environmentally friendly process combining low pressure (vacuum) and mechanical compression to convert low-density polyethylene (LDPE) foams into low-density foams (76–125 kg/m3) with negative tensile and compressive Poisson’s ratios (NPR). As a first step, four series of recycled LDPE foams (electronics packaging) with starting densities of 16, 21, 30 and 36 kg/m3 were used to determine the effect of different processing conditions including temperature and pressure. Based on the optimized conditions, the tensile and compressive Poisson ratios of the resulting auxetic foams reached −2.89 and −0.66, while the tensile and compressive modulus of the auxetic foams reached 40 kPa and 2.55 kPa, respectively. The foam structure of the samples was characterized via morphological analysis and was related to the mechanical properties before and after the treatment (i.e., foams with positive and negative Poisson’s ratios). The tensile and compressive properties (Young’s modulus, strain energy, energy dissipation and damping capacity) for these auxetic foams were also discussed and were shown to be highly improved. These auxetic foams can be applied in sports and military protective equipment. To the best of our knowledge, there is only one report on vacuum being used for the production of auxetic foams.

The aim of this research was to characterize and analyze the formulation of emulsified modification bitumen (EMB) as well as the industrial wastes used in the formulation. Bitumen being a non-renewable product with severe environmental issues arising lately led to the use of industrial wastes such as plastic and recycled base oil in this research. Physical characteristic studies were performed to analyze the decomposition temperature, boiling point, flash point, density, moisture content, element content in waste plastics, and flowability of bitumen emulsion. Eight ratios of modified bitumen were formulated and compared with the industrial grade bitumen. The modified bitumen with a penetration value of 103 mm and softening value at 49 °C was chosen for the emulsification process where three emulsifiers were added into the mixture of bitumen and water. These samples were compared with the industrial bitumen emulsion. From the analysis, the formulated emulsion was obtained from a mixture consists of 20% bitumen, 7% polymer, and 73% recycled base oil.

Objectives. Determination of the influence of molecular weight on the modulus of elasticity, yield, strength, and retardation processes in polyethylene.Methods. We used vane samples (thickness: 4 mm; length: 100 mm; width.: 10 mm) made by injection molding at p = 60 MPa, T = 210 °C, τ = 15 s from the following polyethylenes: HDPE 27773 (Stavrolen, Lukoil, Russia); BorSafe HE3490-IM (Borealis, Austria; black); CRP 100 Hostalen (Basell Polyolefins, Netherlands; black); Stavrolen PE4PP-25B (Stavrolen, Lukoil, Russia; black). The samples were in accordance with the defined standards for the AL 7000 LA-5 tensile testing machine. The study of relaxation characteristics was carried out in two modes: relaxation and retardation.Results. We obtained stress-strain diagrams at various temperatures under isothermal conditions (T = const) and determined the influence of polyethylene molecular weights on the modulus of elasticity, yield, and strength of polyethylenes. We have shown that under isothermal conditions, when the stress equals the yield strength, the removal of the external action results in a two-stage response. The first stage is the stress relaxation. The second stage characterizes the elastic features of the studied materials under the external action ε = const.Conclusions. We have established that temperature increase affects the physicomechanical characteristics of polyethylenes differently, depending on their molecular weights. The experiments have shown that when the stress exceeds the yield strength, at constant deformation, there is a complex response of the polyethylenes to external action. This response is characterized by two stress stages throughout the course of time. The first stage is characterized by asymptotic decrease in stress down to a constant value; the second stage is characterized by constant stress throughout the course of time. We have determined relaxation times for the relaxation stage (stage I) and calculated activation energy. We have also established that the activation energy depends on molecular weights of the polyethylenes. It has been shown that an increase in polyethylene molecular weight leads to a decrease in relaxation time and activation energy.

The recycling of waste materials has become an important topic worldwide. Wastes can be effectively used in concrete to improve its characteristics. This study aimed to research cement mortar’s physical properties, mechanical properties, and durability. In a cement mortar with a fixed water-to-binder ratio (W/B) of 0.5, waste polyethylene (PE) was added at sand volume ratios of 0%, 1%, 2%, 3%, and 4%. Cement was replaced with 0%, 10%, and 20% ground granulated blast furnace slag (GGBFS). The results showed that the slump and flow of mortar tended to decline as the added amount of waste PE increased, but they also increased with the increased replaced amount of GGBFS. The setting time of mortar was shortened as the waste PE increased but delayed as the amount of GGBFS increased. In terms of mechanical properties, the compressive strength of mortar declined as the replaced amount of waste PE increased. Using the GGBFS to replace part of the cement can improve the later mortar strength. This study found that when the added waste PE was within 2% and the replacement amount of GGBFS was 10%, the goal of recycling waste was reached most effectively, while maintaining the concrete’s mechanical properties.

We continue to examine the spectra of polymers because they are important materials, and this exercise makes for an excellent infrared (IR) spectral interpretation review. In this installment, we look [...]

This article describes the operation principle of an extrusion line for producing a polypropylene film for sleeves. The advantages and disadvantages of the technological and structural nature for an extrusion line are presented, as well as the stages of polymer sleeves with the calculation of technological parameters and a description of the main purpose of each stage. The film quality is described, such as the turbidity, coefficient of friction, glossiness, and breaking strength. The dependence of the milkiness on the average cooling temperature of the extruder head is defined. The glossiness dependence is calculated on the cooling temperature of the extruder head. The dependence of the friction coefficient on the cooling temperature of the extruder head was established. The influence of the crystallization line height on the glossiness of the film is defined. The influence of the crystallization line height on the milkiness is shown. The dependence of fluctuations in the average thickness (thickness difference) of the film on the thickness of the forming slot is found. The dependence of fluctuations in the average thickness (thickness difference) of the film and degree of inflation of the sleeve is discovered. The relationship between the quality parameter of the film and technological parameters of its production process has been determined. An automated system for temperature control has been developed in the production of polyethylene film by installing a temperature sensor with feedback.

Currently, halogen-free cable compositions are becoming increasingly common in the manufacture of cable compositions. The concept of halogen-free or “zero halogen” becomes a symbol of fire resistance, low-smoke characteristics, low toxicity of volatile products of combustion, the absence of the toxic, corrosive and irritating gas - hydrogen chloride - and other hydrogen halides in the volatile products. More and more manufacturers of cable products are beginning to pay increasing attention to the problems of processing, toxicity and fire safety. It should be noted that the requirements for improving the fire safety of cable products are constantly becoming tougher, since the main problem of most of these polymeric materials is their flammability, high smoke generation and high flame spread rate. In this regard, there is a burning question to increase these characteristics and bring them to the level of compounds based on PVC. The main way to increase the flame-retardant characteristics of halogenfree cable compositions is to introduce mineral fire retardants into these compositions. The study of the composition and packaging of these mineral fillers-flame retardants makes it possible to increase the level of flame-retardant characteristics of halogen-free cable compositions. The paper presents the results of studies on the thermal stability of cable compositions based on PE + EVA mixtures containing magnesium hydroxide crystalline hydrate as a filler-flame retardant. It is shown that cable compositions containing magnesium hydroxide crystal hydrate are characterized by higher heat resistance and thermal stability (~ 2-fold) compared to a polymeric matrix based on PE + SEVA. This allows to process them at high temperatures (more than 200°C) by extrusion and pressure casting.

Aroad-building project in Texas could validate one approach to an increasingly important requirement of flexible packaging design: sustainability. In February, Dow reported that it constructed two private roads at its [...]

Plastic litter is increasingly becoming pervasive in aquatic environments, characterized by circulatory patterns between different compartments and continual loading with new debris. Microplastic pollution can cause a variety of effects on aquatic organisms. This review presents the current knowledge of microplastics distribution and sorption capacity, reflecting on possible bioaccumulation and health effects in aquatic organisms. A model case study reveals the fate and toxic effects of glyphosate, focusing on the simultaneous exposure of aquacultured shrimp to polyethylene and glyphosate and their contact route and on the potential effects on their health and the risk for transmission of the contaminants. The toxicity and bioaccumulation of glyphosate-sorbed polyethylene microplastics in shrimp are not well understood, although individual effects have been studied extensively in various organisms. We aim to delineate this knowledge gap by compiling current information regarding the co-exposure to polyethylene microplastic adsorbed with glyphosate to assist in the assessment of the possible health risks to aquacultured shrimp and their consumers.

The toxic effect of microplastics on living organisms is emerging as a serious environmental issue nowadays. The biofilm formed on their surface by microorganisms can further increase the toxicity, but the mechanism of biofilm formation on microplastics is not yet fully understood because of the complexities of other factors. This study aimed to identify the factors with an important influence on biofilm formation on microplastic surfaces. The microtiter plate assay was used to evaluate the biofilms formed by Pseudomonas aeruginosa PAO1, a model microorganism, on four types of microplastics, including polyethylene, polystyrene, polypropylene, and polytetrafluoroethylene. The density of microplastics was found to be a key factor in determining the amount of biofilm formation because the density relative to water has a decisive effect on the behavior of microplastics. Biofilm formation on plastics with densities similar to that of water showed remarkable differences based on surface characteristics, whereas biofilm formation on plastics with a higher density was significantly influenced by particle movement in the experimental environment. Furthermore, biofilm formation was inhibited by adding a quorum quenching enzyme, suggesting that QS is critical in biofilm formation on microplastics. This study provides useful information on biofilm formation on microplastic surfaces.

Nowadays, the thermal and catalytic decomposition of plastic wastes by pyrolysis is one of the best alternatives to convert these wastes into quality fuel oils, thus replenishing some petroleum resources. This work studied the catalytic pyrolysis of polyethylene film waste from the remaining organic fraction on different catalysts under dynamic operating conditions in a batch reactor. These catalysts have been characterized through isotherms of adsorption-desorption with N2 and X-ray powder diffraction for structural characterization to see the differences in their use. The results obtained have been compared with the pyrolysis of the same material without a catalyst. Special attention has been paid to the similarities and differences with thermal pyrolysis. The characterization of the liquid fraction, including physical and chemical properties, has been carried out. The liquid yield varies from 37 to 43%; it has good calorific values of 46–48 MJ/kg, an average density of 0.82 g/cm3, and a fairly low viscosity compared to the product without the catalyst. Other properties like the American Petroleum Institute (API) gravity or pH were also determined and found to be similar to conventional fuels. Oils are mainly composed of paraffins, naphthenes, and aromatic hydrocarbons. The general distribution of carbons is C7 to C31. Finally, a detailed analysis of the composition of liquid products shows they present heavy naphtha, kerosene, and diesel fractions in different proportions in the function of the catalyst used.

Sliding tests with a polyethylene (PE) pin against aluminum (Al) and titanium (Ti) disks were conducted under dry conditions, in n-undecane and in ethanol using a unidirectional pin-on-disk machine to evaluate lubrication compatibility. Compared to the dry condition, n-undecane lubrication reduced friction of both the PE pin/Al disk pair and PE pin/Ti disk pair and increased the wear of the tested materials other than PE pin slid against Ti disk. Ethanol lubrication reduced friction and wear of the PE pin/Ti disk pair but increased those of the PE pin/Al disk pair. In all environments tested, the wear of the PE pin/Ti disk pair was lower than that of PE pin/Al disk pair. Profile measurements of the wear tracks on the disks, microstructural observation and chemical analysis of the worn surfaces were performed. The results suggest that the tribological behavior was influenced by the abrasive wear resistance of the metal, the permeability of the solvent into PE, chemical reactivity of the solvent and the thermal conductivity of the metal.

In the present work, Polyethylene- Rhodamine B composites at various concentration of Rhodamine B dye in 200 µm thickness were fabricated. Various influencing concepts like radiation time and concentration on photodegradtion of Rhodamine B in solid state was investigated. The oxidation was studied by FT-IR spectroscopy and it was shown that the oxidation products consisting carbonyl group are obtained. All samples exhibited significant changes in color with exposure conditions. Results indicated that the photodegradation efficiency was increased by rising radiation intensity, dye concentration and time of exposure. Also, it was showed that the photodegradation kinetics obeys a first-order kinetic model.

The high thermal conductivity and good insulating properties of boron nitride (BN) make it a promising filler for high-performance polymer-based thermal management materials. An easy way to prepare BN-polymer composites is to directly mix BN particles with polymer matrix. However, a high concentration of fillers usually leads to a huge reduction of mechanical strength and optical transmission. Here, we propose a novel method to prepare polyethylene/boron nitride nanoplates (PE/BNNPs) composites through the combination of electrostatic self-assembly and hot pressing. Through this method, the thermal conductivity of the PE/BNNPs composites reach 0.47 W/mK, which gets a 14.6% improvement compared to pure polyethylene film. Thanks to the tight bonding of polyethylene with BNNPs, the tensile strength of the composite film reaches 1.82 MPa, an increase of 173.58% compared to that of pure polyethylene film (0.66 MPa). The fracture stress was also highly enhanced, with an increase of 148.44% compared to pure polyethylene film. Moreover, the addition of BNNPs in PE does not highly reduce its good transmittance, which is preferred for thermal management in devices like light-emitting diodes. This work gives an insight into the preparation strategy of transparent and flexible thermal management materials with high thermal conductivity.

The annual global production of plastics reached 335 million metric tons in 2016. Most waste plastics are landfilled or enter the natural environment in an uncontrolled manner. Pyrolysis can convert waste plastics, such as polyethylene (PE), to smaller hydrocarbons that can be used as fuels or chemicals. In this work, pyrolysis of PE was studied by thermogravimetric analysis (TGA) and in a fluidized‐bed reactor. A kinetic model based on two parallel first‐order random‐scission steps was developed on the basis of the TGA results. PE was pyrolyzed in a fluidized‐bed reactor over the temperature range of 500–600 °C and at residence times of 12.4–20.4 s. The yield of gas‐phase products increased from 8.2 to 56.8 wt %, and the yield of liquid‐phase products decreased from 81.2 to 28.5 wt % as the temperature increased from 500 to 600 °C. Detailed analysis of the gas‐ and liquid‐phase products revealed their potential as precursors for production of fuels and chemicals. Gas‐phase products included hydrogen, C1–C4 paraffins, C2–C4 olefins, and 1,3‐butadiene. The major liquid‐phase products were mono‐olefins and cycloalkanes/alkadienes with smaller amounts of n‐paraffins, isoparaffins, and aromatics. The carbon‐number distribution of the fluidized‐bed pyrolysis products suggested contributions of nonrandom reactions of random‐scission fragments at low conversion. [ABSTRACT FROM AUTHOR]

Background: Multiple cases of dissociation of the head from the neck termed as gross trunnion failure (GTF) in total hip replacement have been described. Very little quantitative data is available for patient and implant factors associated and predisposing to this complication.Study Purpose: To systematically review and analyze all studies which have gross trunnion failure in case of metal on polyethylene (MoP) total hip replacement.Methods: PubMed database was searched. We also performed a secondary search by pearling bibliography of all full text articles obtained. Predefined inclusion and exclusion criteria were used for abstract screening by two independent observers. A total 46 cases met our inclusion criteria. These were included in the final analysis and data was pooled.Results: Till date, 46 cases of GTF in MoP THR have been reported. The mean age at time of revision was 70.13 years (range 50 to 89 years). The mean time to revision surgery was 8.24 years (range 4.7 to 14 years). 91.4% cases were male. BMI was ≥ 25 in 38/41 cases and ≥ 30 in 21/41 cases. Pain (95.5%) and difficulty or inability to walk (97.7%) were the most common symptoms. A total of 19/44 cases described varying sounds like click, clunk, and pop before dislocation. Accolade TMZF/TMZF plus was the most common stem used in 34/46 cases. The stem neck angle was 127 degrees in 97% cases (32/33 cases). A positive neck offset of 4 mm or more was used in 91.1% cases (40/44 cases). The head size ≥ 36 mm in approximately 90% cases. The head material was cobalt chromium in all 45 cases, where data was available. Among the intra-operative findings, the most common findings were metallosis (41/44), black or brow coloured synovial fluid (21/44), pseudotumour (19/44), synovial hypertrophy (18/44), damage to the abductor musculature (17/44), proximal femoral osteolysis (5/44 cases), and heterotrophic ossification (2/44 cases). Histopathological analysis was available in 11 cases and was suggestive of fibrous tissue with chronic cellular infiltrate in all cases. The serum cobalt and chromium concentrations were raised above normal in 86.4% (19/22) and 21.7% cases (5/23) respectively.Conclusions: Gross trunnion failure may not be as uncommon as was previously thought. A number potential associations and predisposing factors of this complication have been highlighted in this review. But due to small sample size and weak level of evidence, further studies are needed in this field. [ABSTRACT FROM AUTHOR]