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The article considers the possibility of involving in the technological production of commercial greases, secondary polymeric raw materials represented by such polyolefins as high and low density polyethylene (LDPE and HDPE) and polypropylene (PP). The results of laboratory studies of the obtained greases samples are presented. On the basis of the obtained results, a scheme for the production of greases is proposed, in which the stage of dispersion of components is realised by boiling the polymer in the base oil. The proposed scheme makes it possible to reduce the degree of grinding of polymer raw materials, which reduces energy consumption and the duration of preliminary preparation of the polymer thickener. [ABSTRACT FROM AUTHOR]

Driven by dwindling oil resources and rising energy demands, researchers are exploring ways to convert waste products into high-quality fuels that can replace fossil fuels. Plastic waste, a growing concern, can be a valuable resource. This study investigates the potential of fuel oil (FO), derived from waste plastic (lowdensity polyethylene), as a fuel source. Fuel oils were produced from low-density polyethylene at 340°C and 450°C, respectively. The properties of these oils and their blends with commercial diesel were analysed using the American Society for Testing and Materials (ASTM) Method. Engine tests were then conducted using fuel oil and compared to diesel. The blend also resulted in slightly higher carbon dioxide (CO2), oxides of nitrogen (NOx), and unburned hydrocarbons (HC). However, there is a similarity in brake thermal efficiency, specific fuel consumption, and carbon monoxide emissions of fuel oil and diesel. Notably, adding diesel to fuel oil improves engine performance. The fuel properties of the fuel oil obtained from LDPE were comparable to diesel, suggesting potential direct use as engine fuel or refinery feedstock. The engine runs smoothly and is conducted up to a 30% blend, with improved brake thermal efficiency and lower fuel consumption than pure diesel. This highlights the need for further research on fuel fractionation or engine modifications to optimise performance and minimise emissions [ABSTRACT FROM AUTHOR]

The aggregation of plastic waste results in immiscible polymer blends with inferior properties. This study explores the application of irradiation technology on polymer processing for its potential to increase the compatibility of immiscible polymer blends composed of poly(ethylene terephthalate) (PET) and linear low‐density polyethylene (LLDPE). When PET is radiated, it undergoes chain‐scission reactions resulting in the formation of free radicals. The extended lifespan of these free radicals in post‐irradiated PET provides an opportunity for inducing interface reactions with LLDPE during compounding through reactive extrusion. PET was irradiated with up to 50 and 200 kGy irradiation absorbance doses of gamma irradiation and then compounded with LLDPE in a twin‐screw extruder at three blend compositions. Analysis of rheological, morphological, and mechanical properties demonstrates the compatibility improvement in this immiscible polymer blend attributed to irradiation‐induced free radical interface reactions using post‐irradiated PET up to 50 kGy to conduct the reactive extrusion process. Highlights: Reactive extrusion process with post‐irradiated PET.Formation of interface reactions.Improving the compatibility of immiscible polymer blend. [ABSTRACT FROM AUTHOR]

This study was conducted to ascertain the negative effects of dietary low-density polyethylene microplastics (LDPE-MPs) exposure on growth, nutrient digestibility, body composition and gut histology of Nile tilapia (Oreochromis niloticus). Six sunflower meal-based diets (protein 30.95%; fat 8.04%) were prepared; one was the control (0%) and five were incorporated with LDPE-MPs at levels of 2, 4, 6, 8 and 10% in sunflower meal-based diets. A total of eighteen experimental tanks, each with 15 fingerlings, were used in triplicates. Fish were fed at the rate of 5% biomass twice a day for 60 days. Results revealed that best values of growth, nutrient digestibility, body composition and gut histology were observed by control diet, while 10% exposure to LDPE-MPs significantly (P < 0.05) reduced weight gain (WG%, 85.04%), specific growth rate (SGR%, 0.68%), and increased FCR (3.92%). The findings showed that higher level of LDPE-MPs (10%) exposure in the diet of O. niloticus negatively affects nutrient digestibility. Furthermore, the results revealed that the higher concentration of LDPE-MPs (10%) had a detrimental impact on crude protein (11.92%) and crude fat (8.04%). A high number of histological lesions were seen in gut of fingerlings exposed to LDPE-MPs. Hence, LDPE-MPs potentially harm the aquatic health. [ABSTRACT FROM AUTHOR]

Significant interest is devoted to the development of new polymer blends by using concepts of the circular economy. Such materials have predetermined properties, are easy to recycle, ecological, and have a low carbon footprint. This research presents obtaining and characterization of polymer blends based on low-density polyethylene (LDPE) and thermoplastic starch (TPS). In the first stage, TPS was obtained through the gelatinization process, and, in the second stage, mixtures of LDPE and TPS were obtained through a melt mixing process at 150 °C for 7 min. The physical–mechanical characteristics of the samples, like hardness, elongation at break, rebound resilience, and tensile strength, were determined. The sample containing maleic anhydride grafted low-density polyethylene (LDPE-g-MA) as a compatibilizer shows improvements in elongation at break and tensile strength (by 6.59% and 40.47%, respectively) compared to the test sample. The FTIR microscopy maps show that samples containing LDPE-g-MA are more homogeneous. The SEM micrographs indicate that TPS-s is homogeneously dispersed as droplets in the LDPE matrix. From the thermal analysis, it was observed that both the degree of crystallinity and the mass loss at high temperature are influenced by the composition of the samples. The melt flow index has adequate values, indicating good processability of the samples by specific methods (such as extrusion or injection). [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Low-density polyethylene is one of the dominant recalcitrant plastic pollutants in the ocean, thus causing complicated problems. Biodegradation is an efficient, environmentally friendly, and sustainable option to overcome these problems. This study aims to quantitatively and qualitatively analyze the ability of marine bacterial isolates to degrade lowdensity polyethylene plastic. METHODS: Bacteria were isolated from plastic samples using serial dilution technique and inoculated on media containing low-density polyethylene powder. Bacterial degradation ability was analyzed quantitatively based on weight loss percentage and energy-dispersive X-ray spectroscopy values, as well as qualitatively based on changes in physical and chemical structures using Scanning Electron Microscopy and Fourier transform infrared spectroscopy. Meanwhile, bacterial isolates were identified based on gene sequence and phylogenetic analyses. FINDINGS: Four bacterial isolates were isolated from low-density polyethylene plastic samples. Quantitative analysis found that the low-density polyethylene film experienced weight loss up to 10-15 percent during 35 days of incubation, with a maximum daily weight loss rate of 0.004 milligrams per day, meaning that the four bacterial isolates have the potential to degrade plastic. Meanwhile, qualitative analysis based on Scanning Electron Microscope observations revealed changes in the physical structure of the film surface in the form of a rough surface, formation of holes, and breakdown into clumps across the film surface. Variations in these changes were tested. In the control, no changes occurred and the film surface remained flat and smooth. Conversely, the results of the energy dispersive X-ray spectroscopy spectrum analysis showed that the lowdensity polyethylene film broke down into smaller fragments, characterized by a decrease in mass from 98.51 percent to 98.23 percent. Fourier transform infrared observations showed variations in transmittance and wavenumbers, indicating changes in chemical bonds or functional groups in the low-density polyethylene film which caused it to become brittle and break down into smaller fragments with a lower molecular weight, making it easier for bacteria to digest. The results of the gene sequence analysis identified four bacterial isolates, namely Lysinibacillus sp. IBP-1, Bacillus sp. IBP-2, Bacillus paramycoides IBP-3, and Bacillus cereus IBP-4. Based on the quantitative and qualitative analyses, the ability of the bacterial isolates to degrade low-density polyethylene film was shown in the following order: Bacillus paramycoides IBP-3 > Bacillus cereus IBP-4 > Lysinibacillus sp. IBP-1 > Bacillus sp. IBP-2. CONCLUSION: All four marine bacterial isolates can use low-density polyethylene as the sole carbon source. Based on quantitative and qualitative analyses, Bacillus paramycoides IBP-3 has the best potential for degrading low-density polyethylene film. This study provides information on potential bacterial isolates that can be developed to control low-density polyethylene plastic waste. [ABSTRACT FROM AUTHOR]

The interaction of microcroplastics (MP) with dissolved organic matter, especially humic substances, is of great importance in understanding the behavior of microplastics in aquatic ecosystems. Surface modification by humic substances plays an essential role in transport and interaction of MP with abiotic and biotic components. Previous studies on the interaction between MP and humic substances were largely based on a model compound, humic acid (Sigma‐Aldrich). In our work, we therefore investigated the interaction of natural organic matter (NOM) sampled from a German surface water with low‐density polyethylene particles (LDPE). High‐pressure size exclusion chromatography (HPSEC) and UV/vis absorption and fluorescence spectroscopy were used to characterize the incubation solutions after modifications due to the presence of LDPE, and Raman spectroscopy was used to characterize the incubated microplastics. While the studies of the solutions generally showed only very small effects, Raman spectroscopic studies allowed clear evidence of the binding of humic fractions to MP. The comparison of the incubation of NOM and a lignite fulvic acid which also was tested further showed that specific signatures of the humic substances used could be detected by Raman spectroscopy. This provides an elegant opportunity to conduct broader studies on this issue in the future. [ABSTRACT FROM AUTHOR]

The selective distribution of filler within polymer blends presents a compelling advantage, notably manifesting as a reduced percolation threshold when compared to an individual polymer matrix with a random filler dispersion. In this context, a thermoplastic elastomeric (TPE) blend comprising ethylene propylene diene rubber (EPDM) and linear low-density polyethylene (LLDPE), denoted as EL, has been meticulously formulated. The incorporation of varying amounts of conductive carbon black (Vulcan XC 72; VCB) into this TPE matrix has been achieved through conventional melt blending, yielding a composite material with exceptional electromagnetic interference (EMI) shielding effectiveness of -27.80 dB at 50 phr (parts per hundred rubber). This success is credited to the creation of a linked structure resulting from a dual-step percolation process. The selective distribution of carbon black (CB) throughout the TPE mixture results in a decreased critical concentration for connectivity and enhanced electromagnetic interference (EMI) shielding performance. This advancement underscores the potential of EPDM-LLDPE-VCB (ELV) composites to safeguard against electromagnetic radiation. It paves the way for their utilization in various techno-commercial applications, where a balance of mechanical strength, thermal stability, and flexibility is crucial. [ABSTRACT FROM AUTHOR]

The decline in the quality of waste management has generally started to occur since the prolonged economic crisis in Indonesia. Plastic waste includes inorganic waste, which is currently widely used by industry and households. Therefore, it is necessary to have an alternative recycling process, like converting plastic waste into liquid fuel. The research objective is to utilize LDPE plastic waste (Low-Density Polyethylene) and PP (Polypropylene)in liquid fuelutilizing pyrolysisto determine the effect of using a zeolite catalyst by comparing the results of the pyrolysis process. The investigation took place at the Wonosari landfill in Singkawang, where parameters such as density, viscosity, and color were examined. The pyrolysis results underwent consistency testing through the Mann-Whitney test. According to the study findings, the average physical parameter values for viscosity and density of LDPE pyrolysis liquid fuel were 0.302 cP, LDPE+catalyst was 0.114 cP, with densities of 767 kg/m3 and 737 kg/m3. For PP, the average viscosity was 2.812 cP, and PP+catalyst was 0.248 cP, with densities of 774 kg/m3 and 735 kg/m3. Samples of PP and LDPE with catalysts exhibited lower density values compared to those without catalysts.

The MV X-Press Pearl maritime incident had a profound impact on the marine and coastal ecosystems along the west coast of Sri Lanka. Considerable quantities of plastic pellets, specifically nurdles or pellets measuring less than 5 mm and estimated at 1680 tonnes, were released into the Indian Ocean. A notable portion of these plastic pellets/primary microplastics (MPs), has the potential to degrade into secondary MPs. The objective of this study was to investigate and understand the degradation process of plastic pellets into secondary MPs under the extreme conditions of fire and exposure to chemicals during the MV X-Press Pearl maritime disaster. Beach sand samples were collected from 40 locations along the affected west coast of Sri Lanka, at both mean sea level and the berm. An additional 20 samples were collected for a background study covering the entire coastline of Sri Lanka. The Wet Peroxide Oxidation (WPO) process was employed to separate microplastics, and observations of secondary MP quantities were recorded. Fourier Transform Infra-Red Spectroscopic (FTIR) analysis was carried out to identify functional groups of MPs. The variance in average values of secondary MPs at mean sea level (large MPs (i.e. size > 0. 5 mm) = 33 ± 56 items per 1 mm2 and total MPs (i.e. observed through microscope under 40× magnification) = 61 ± 66 items per 1 mm2) and the berm (large = 61 ± 154 items per 1 mm2 and total MPs = 106 ± 165 items per 1 mm2) suggested significant dispersal of large quantities of MPs to other areas in the Indian Ocean with oceanic currents. The baseline average value of secondary total MPs in other coastal areas of the country was approximately 53 ± 66 items per 1 mm2. The positive correlation between large and total secondary MPs and plastic pellets pollution index indicates that a considerable amount of plastic pellets were degraded into secondary MPs within 6 to 8 days after the accident, under the influence of nitric acid and heat/fire. These secondary MPs are mainly composed of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE), as identified by FTIR observations. Consequently, these lightweight polymers have the potential to spread across a wider region, posing a severe environmental threat on a global scale as a transoceanic marine pollutant. [ABSTRACT FROM AUTHOR]

In polyolefins, long-chain branching is introduced through an energy-intensive, high-pressure radical process to form low-density polyethylene (LDPE). In the current work, we demonstrated a ladder-like polyethylene architecture through solution polymerization of ethylene and less than 1 mole % of a, w-dienes, using a dual-chain catalyst. The ladder-branching mechanism requires catalysts with two growing polymer chains on the same metal center, thus enchaining the diene without the requirement of a steady-state concentration of pendant vinyl groups. Molecular weight distributions lacking a high- molecular weight tail, distinctive Mark-Houwink signatures, nuclear magnetic resonance characterization, and shear and extensional rheology consistent with highly branched polyethylene architectures are described. This approach represents an industrially viable solution-polymerization process capable of producing controlled long-chain branched polyethylene with rheological properties comparable to those of LDPE or its blends with linear low-density polyethylene (LLDPE). [ABSTRACT FROM AUTHOR]

Microplastics (MPs) pose a significant risk to humans and animals due to their ability to absorb, adsorb, and desorb organic pollutants. MPs catchment from either sediments or water bodies is crucial for risk assessment, but fast and effective particle quantification of irregularly shaped particles is only marginally addressed. Many studies used microscopy methods to count MP particles, which are tedious for large sample sizes. Alternatively, this work presents an algorithm developed in the free software GNU Octave to analyze microscope images of MP particles with variable sizes and shapes. The algorithm can detect and distinguish different particles, compensate for uneven illumination and low image contrast, find high-contrast areas, unify edge regions, and fill the remaining pixels of stacked particles. The fully automatic algorithm calculates shape parameters such as convexity, solidity, reciprocal aspect ratio, rectangularity, and the Feret major axis ratio and generates the particle size distribution. The study tested low-density polyethylene particles with sizes of 50–100 µm and 200–300 µm. A scanning electron microscope image series analyzed with Octave was compared to a manual evaluation using ImageJ. Although the fully automatic algorithm did not identify all particles, the comprehensive tests demonstrate a qualitatively accurate particle size and shape monitoring applicable to any MPs, which processes larger data sets in a short time and is compatible with MATLAB-based codes. [ABSTRACT FROM AUTHOR]

On the basis of the characteristics of low-density polyethylene determined experimentally from the geometric dimensions of the extruder parts and COMSOL MULTIPHYSICS software a digital model of the apparatus was created, and the flow rate of the polymer melt from the extruder nozzle was calculated hydrodynamically. The agreement between the experimentally measured polymer flow rate and the value obtained from the model lies within the permissible error. This establishes the adequacy of the digital twin model, which will be used to predict the viscosity characteristics of composite materials based on low-density polyethylene and the technological regimes of their production by blending in the extruder. [ABSTRACT FROM AUTHOR]

Electrical properties and electro-thermal behavior were studied in composites with carbon black (CB) or hybrid filler (CB and graphite) and a matrix of linear low-density polyethylene (LLDPE). LLDPE, a (co)polymer with low crystallinity but with high structural regularity, was less studied for Positive Temperature Coefficient (PTC) applications, but it would be of interest due to its higher flexibility as compared to HDPE. Structural characterization by scanning electron microscopy (SEM) confirmed a segregated structure resulted from preparation by solid state powder mixing followed by hot molding. Direct current (DC) conductivity measurements resulted in a percolation threshold of around 8% (w) for CB/LLDPE composites. Increased filler concentrations resulted in increased alternating current (AC) conductivity, electrical permittivity and loss factor. Resistivity-temperature curves indicate the dependence of the temperature at which the maximum of resistivity is reached (Tmax(R)) on the filler concentration, as well as a differentiation in the Tmax(R) from the crystalline transition temperatures determined by DSC. These results suggest that crystallinity is not the only determining factor of the PTC mechanism in this case. This behavior is different from similar high-crystallinity composites, and suggests a specific interaction between the conductive filler and the polymeric matrix. A strong dependence of the PTC effect on filler concentration and an optimal concentration range between 14 and 19% were also found. Graphite has a beneficial effect not only on conductivity, but also on PTC behavior. Temperature vs. time experiments, revealed good temperature self-regulation properties and current and voltage limitation, and irrespective of the applied voltage and composite type, the equilibrium superficial temperature did not exceed 80 °C, while the equilibrium current traversing the sample dropped from 22 mA at 35 V to 5 mA at 150 V, proving the limitation capacities of these materials. The concentration effects revealed in this work could open new perspectives for the compositional control of both the self-limiting and interrupting properties for various low-temperature applications. [ABSTRACT FROM AUTHOR]

The demand for fiber-filled polymers has witnessed a significant upswing in recent years. A comprehensive understanding of the local fiber orientation is imperative to accurately predict the mechanical properties of fiber-filled products. In this study, we experimentally investigated the fiber orientation kinetics in uniaxial extensional flows. For this, we equipped a rheometer with a Sentmanat extensional measurement device and with an optical train that allows us to measure the fiber orientation in situ during uniaxial extension using small angle light scattering. We investigated an experimental system with glass fibers for the suspended phase (L / D = 8 − 15), and for the matrix either low density polyethylene, which shows strain hardening in extension, or linear low density polyethylene, which shows no strain hardening. For these two polymer matrices, the fiber orientation kinetics were investigated as a function of fiber volume fraction (ϕ = 1 % , 5%, and 10%) and Weissenberg number (by varying the Hencky strain rate, ϵ ˙ H = 0.01 − 1 s − 1 ). We found that all these parameters did not influence the fiber orientation kinetics in uniaxial extension and that these kinetics can be described by a multiparticle model, based on Jeffery's equation for single particles. Our results show that, in uniaxial extension, fiber orientation is solely determined by the applied strain and that, up to the concentrated regime (ϕ ≈ D / L), fiber-fiber interactions do not influence the fiber orientation. The extensional stress growth coefficient of these composites, which is measured simultaneously with the orientation, shows high agreement with Batchelor's equation for rodlike suspensions. [ABSTRACT FROM AUTHOR]

This study deals with removing crude oil droplets from colloidal oil in water emulsions. The target was the development of efficient adsorbents for the tertiary treatment of industrial-produced water (PW). The novel adsorbent was designed from recycled low-density polyethylene (LDPE) powder grafted by the cationic polymer. The cationic polymer was synthesized directly on the LDPE surface by plasma-induced radical polymerization. A positively charged adsorbent was chosen due to the negative character of oily droplets to enhance separation efficiency in treating oil-water emulsions. The separation was performed in both batch and filtration modes. Absorption/adsorption uptake capacities showed a sigmoidal S-shape that was analyzed using the Sips model and compared with the newly developed empirical model. Both models showed a remarkable coincidence in the description of experimental data. The separation efficiency of the novel adsorbent was also tested in a filtration mode mimicking a commonly used deep-bed filtration technology. The comparison of the separation efficiency for various sorbents indicated a supreme performance of novel adsorbent. This study demonstrates the potential of a relatively cheap, prepared commodity-based adsorbent for the purification of emulsified oily polluted water in both batch and filtration configurations. This study also contributes to the recycling of polyethylene waste because LDPE attracts meager interest in recycled LLDPE due to many obstacles to reusing LDPE waste for its reprocessing as packaging materials. [ABSTRACT FROM AUTHOR]

The use of natural raw substances for food preservation could provide a great contribution to food waste reduction, circular economy enhancement, and green process application widening. Recent studies indicated that the use of porous materials as adsorbents for natural essential oils provided nanohybrids with excellent antioxidant and antimicrobial properties. Following this trend in this work, a thymol oil (TEO) rich SBA-15 nanohybrid was prepared and characterized physiochemically with various techniques. This TEO@SBA-15 nanohybrid, along with the pure SBA-15, was extruded with low-density polyethylene (LDPE) to develop novel active packaging films. Results indicated that TEO loading was higher than other porous materials reported recently, and the addition of both pure SBA-15 and TEO@SBA-15 to the LDPE increased the water/oxygen barrier. The film with the higher thyme-oil@SBA-15 nanohybrid content exhibited a slower release kinetic. The antioxidant activity of the final films ignited after 48 h, was in the range of 60–70%, and was almost constant for 7 days. Finally, all tests indicated a sufficient improvement by the addition of thyme-oil@SBA-15 nanohybrids in the pure LDPE matrix and the concentration of wt. 10% of such nanocarriers provided the optimum final LDPE/10TEO@SBE-15 active packaging film. This material could be a potential future product for active packaging applications. [ABSTRACT FROM AUTHOR]

This manuscript presents a comprehensive study on the sustainable optimization of asphalt mixtures tailored for regions prone to flooding. The research addresses the challenges associated with water damage to asphalt pavements by incorporating innovative additives. The study centers on incorporating recycled Low-Density Polyethylene (LDPE) and a tailored Carnauba–Soybean Oil Additive, advancing asphalt mixtures with a Control mix, LDPE (5%) + Control, and LDPE (5%) + 3% Oil + Control. A critical aspect of the research involves subjecting these mixtures to 30 wetting and drying cycles, simulating the conditions prevalent in tropical flood-prone areas. The incorporation of innovative additives in asphalt mixtures has demonstrated significant improvements across various performance parameters. Tensile Strength Ratio (TSR) tests revealed enhanced tensile strength, with the LDPE (5%) + 3% Oil-modified mixture exhibiting an impressive TSR of 85.7%. Dynamic Modulus tests highlighted improved rutting resistance, showcasing a remarkable increase to 214 MPa in the LDPE (5%) with a 3% Oil-modified mixture. The Semi-Circular Bending (SCB) test demonstrated increased fracture resistance and energy absorption, particularly in the LDPE (5%) with 3% Oil-modified mixture. Hamburg Wheel-Tracking (HWT) tests indicated enhanced moisture resistance and superior rutting resistance at 20,000 cycles for the same mixture. Cantabro tests underscored improved aggregate shatter resistance, with the LDPE (5%) + 3% Oil-modified mixture exhibiting the lowest weight loss rate at 9.820%. Field tests provided real-world insights, with the LDPE (5%) + 3% Oil mixture displaying superior stability, a 61% reduction in deflection, and a 256% improvement in surface modulus over the control mixture. This research lays the groundwork for advancing the development of sustainable, high-performance road pavement materials, marking a significant stride towards resilient infrastructure in flood-prone areas. [ABSTRACT FROM AUTHOR]

Rotational Molding is defined as a plastic manufacturing method wherein a benefit of stress-free plastic product is accessible. Linear Low-Density Polyethylene (LLDPE) has consistently been on elevated priority as base material for rotomolded product. Notwithstanding, LLDPE requires to annotate its strength as needed in couple of applications. Added substances or fillers can fill the void to upgrade the mechanical properties. A legitimate choice of additives to convey a suitable required mechanical property in rotationally molded product has consistently been on research mode. Composites prepared using synthetic fibers have always proved to sustain better mechanical properties in the end product. Multi-criteria dynamic procedures were utilized to address the selection of a suitable additive considering various attributes from an enormous number of options. In the current context of investigation, multi criteria decision making techniques (MCDM) like TOPSIS and MOORA strategies were made as a wellspring of help to select the feasible synthetic fiber that can be opted for blending with the base resin for rotational molding process. MCDM techniques has been observed to be fruitful in solving the real time problems for selection of materials. The findings thus attained are relatively reasonable and can be used in the design process of the roto-molded product for blending with the resin. Polyester from synthetic fibers was classified as the top-ranking material based on the characteristics used in deciphering these methods. [ABSTRACT FROM AUTHOR]

This paper investigates the addition of lecithin‐emulsified black seed oil (BSO) nanoemulsions (LNEO) and whey protein isolate‐stabilized Pickering emulsions (WPEO) to soy protein isolate (SPI)‐based films and their effect on improving the shelf life of bread slices. The half‐life of antioxidant activity, water vapor permeability, biodegradability, density, color difference, and film thickness significantly increased (p <.05) when BSO was added. However, the incorporation of BSO significantly reduced the solubility, tensile strength, strain to break (except for WPEO), and transparency (p <.05) of the samples. The interaction between SPI film and BSO‐loaded nanocarriers, as well as the morphological properties of films, was evaluated using FT‐IR and FE‐SEM. SPI‐based films containing LNEO‐5% and WPEO‐5% were selected based on their mechanical and barrier properties. The effect of films on the shelf life of bread slices was investigated for 17 days of storage. LNEO samples obtained the most acceptable results in the bread in terms of sensory evaluation and color properties. According to the results, bread slices packed in SPI film containing LNEO‐5% showed no signs of mold growth until the 17th day of storage, whereas the sample packed in a low‐density polyethylene bag began to corrupt on the 6th day. This study highlights the potential of BSO‐loaded SPI films as a novel active packaging for the bakery industry. [ABSTRACT FROM AUTHOR]

Global plastic pollution is one of the serious issues which create a severe environmental damage. Microbial biodegradation is an eco-friendly method to overcome the plastic pollution issue. The aim of this study is to explore microbes from garbage soil to manage the Low-density Polyethylene (LDPE). Active biodegrading microbes were identified by clear zone method using mineral salt medium with LDPE. Genome sequencing has been performed for LDPE-degrading strains and identified as Bacillus subtilis and Streptomyces labedae. The biodegradation of LDPE was carried out by using selected active strains. The analysis of biodegradation process was carried out by extracellular enzyme assay, cell hydrophobicity and viability of cells with elevated pH produced by B.subtilis and S.labedae. The weight loss percentage of polymer sheets by B.subtilis and S.labedae were 80% and 85% respectively. Major deformities and surface modification on the LDPE sheet were evaluated by the formation of cracks and pits on the surface. The functional groups in the treated sheets were observed by using FTIR analysis. The highest reduction in tensile strength was observed. The GC-MS analysis revealed the presence of 30 new compounds during the biodegradation. It evolved CO2 of 5.32 g/l with S. labedae and 4.55 g/l with B.subtilis. Phytotoxicity of LDPE degraded byproduct showed a positive growth rate of 97.8 ± 0.836% in Trigonella foenum seed. Then the cytotoxicity study revealed that it was non-toxic to L292 cell lines. Both strains have the ability to consume and reduce the LDPE film. These organisms are the promising resources to manage the LDPE and offers an ecofriendly solution to solve global plastic pollution. Hence the achieved research information could be applied at a large scale for degrading various plastic materials. [ABSTRACT FROM AUTHOR]

In tubular reactors, fouling issues are caused due to two reasons. One is the heating–cooling prerequisite, and the other is the exothermic nature of the low‐density polyethylene (LDPE) polymerization process. These issues must be considered while optimizing LDPE production to provide maximum productivity and a safe operation. However, it is not a simple process because the conversion of the monomer (XM) is generally related to significant profits. This conversion might be performed at high reaction temperatures, resulting in fouling formation. Therefore, in this research, a study of dynamic optimization to find the most efficient production of LDPE in the presence of fouling resistance (Rf) restrictions is conducted. An Rf is employed as a measure of fouling. To establish the highest reactor RfRfmax=50cm2sK/cal$$ \left({R}_{f_{\mathrm{max}}}=50\ \mathrm{cm}2\ \mathrm{s}\ \mathrm{K}/\mathrm{cal}\right) $$, this study employs variations in the heat transfer coefficient (U) calculated from industry data. This dynamic optimization study addresses the optimization challenges using dynopt coded programming based on orthogonal collocation (OC) and sequential quadratic programming methodologies. Beforehand, the LDPE model is validated with industrial data. This study evaluates three possibilities to determine the most optimum reactor performance. The most optimum reactor output is determined from the constrained maximum conversion, which gave 32.15% conversion, while the Rf$$ {R}_f $$was effectively met at 47.37cm2 s K/cal. [ABSTRACT FROM AUTHOR]

Opening agent is used in the production of plastic films, which can effectively improve the opening properties of the film. In this paper, four kinds of silica (SiO2) opening agents were synthesized by precipitation method, and four kinds of LLDPE/SiO2 masterbatch were prepared by melt blending with linear low density polyethylene (LLDPE) under the same processing conditions. The results show that the four kinds of opening agents can meet the requirements of anti-sticking and opening performance of LLDPE film, and the dynamic/static friction coefficients are all reduced to less than 0.11 (belonging to high smoothness). After compacting at 50 °C and 7 kPa for 24 h, there was no adhesion between the four LLDPE/SiO2 films, but pure LLDPE films had some adhesion. AFM test shows that there are micro pits near the submicron SiO2 opening agent particles, which play a key role in reducing negative pressure and van der Waals force, thus reducing the adhesion of LLDPE/SiO2 films. Based on the test data, a model of anti-sticking opening for LLDPE film is proposed, which is expected to be used to guide the production of opening agents with higher anti-sticking opening efficiency. [ABSTRACT FROM AUTHOR]

Post‐industrial low‐density and linear low‐density polyethylene blown films are mechanically recycled for reutilizing in the production of blown films for packaging applications. This process enables the production of films with lower cost and similar properties while preserving the environment and lowering the amount of waste material disposed of. The mechanical recycling process results in the production of recycled pellets. This process includes chopping, washing, drying, and reprocessing. Mixtures of these recycled materials and their virgin form with various concentrations are shaped into blown films with inherent 70 and 30 wt% loadings for low‐density polyethylene and linear low‐density polyethylene components, respectively. Fourier transform infrared spectroscopy results of the recycled material show no contamination or chemical reaction with other materials. Gel permeation chromatography is carried out on the virgin and recycled low‐density polyethylene and linear low‐density polyethylene, and the results indicate the occurrence of chain session and crosslinking during the recycling process. The decline in the thermal properties of the samples, seen from the differential scanning calorimetry results, indicates the presence of crosslinks. The effect of structural changes caused by the recycling process on the rheological properties is studied. The miscibility of the blend components is evaluated by Cole–Cole plots and then further proved by Han and Van Gurp–Palman curves. Mechanical properties display an upturn following the presence of the crosslinkes. A decline in the optical properties in the films caused by the refraction of light by the crosslink structure in the film bulk and on the surface is evident. Highlights: LDPE and LLDPE were recycled according to the circular economy approachBlown films containing virgin and recycled LDPE and LLDPE were producedChain scission and crosslinking as a result of recycling were studiedRheological, thermal, mechanical, and optical properties were studied [ABSTRACT FROM AUTHOR]

The escalating frequency of oil spill incidents and industrial wastewater discharges necessitates the development of effective remediation strategies. In this study, we conduct a comprehensive computational investigation using density functional theory (DFT) to elucidate the interaction mechanisms within polyethylene (PE) combined with polyurethane (PU) and hexane. The study focuses on adsorption energies, intermolecular interactions, miscibility, and electronic properties, providing a molecular‐level understanding crucial for designing advanced absorbent materials. The investigation reveals that the low‐density polyethylene/polyurethane (LDPE/PU) system exhibits significantly higher adsorption energies (−12.87 kcal/mol) compared to PE/hexane (−7.66 kcal/mol), indicating a robust binding affinity. This discrepancy underscores the superior performance of PE/PU as an absorbent material. The enthalpy results, with ∆H values of −55.75 kcal/mol for PE/hexane‐n‐hexadecane and −66.11 kcal/mol for PE/PU‐n‐hexadecane complexes at 298.15 K, support exothermic adsorption. The more exothermic ∆H for PE/PU indicates stronger interactions during oil absorption than PE/hexane. Additionally, Gibbs free energy change (∆G) values affirm a more favorable process for PE/PU, exhibiting a lower ∆G (−42.54 kcal/mol) compared to PE/hexane (−34.79 kcal/mol). Non‐covalent interaction (NCI) studies confirm the importance of van der Waals forces in both systems, validating their role in the adsorption process. Miscibility studies indicate limited interactions, with PE/PU showing positive enthalpy of mixing. Electronic study demonstrates PE/PU's higher energy gap of 9.19 eV, correlating with superior performance. This research contributes to the fundamental understanding of oil absorption processes and informs the design and optimization of environmentally sustainable and efficient oil‐absorbing materials for remediation applications. Highlights: DFT explores polymeric systems, PE/PU and PE/hexane, for oil absorbent.PE/PU excels with −12.87 kcal/mol adsorption energy, surpassing PE/hexane (−7.66 kcal/mol).NCI validates van der Waals forces in both systems, crucial for effective adsorption.Miscibility studies reveal limited interactions.PE/PU's superior 9.19 eV energy gap signifies enhanced absorbent performance.PE/PU excels as an oil‐absorbent material, underlining its overall superiority. [ABSTRACT FROM AUTHOR]

It can be observed that magnetic iron-oxide nanoparticles are increasingly used in bioassay methods. This is due to their stability in aqueous solutions, ease of functionalization, biocompatibility and very low toxicity. Here, we show that the recent discovery of the ability of magnetic nanoparticles to self-assemble into 2D structures of ordered chains may be exploited for bioassays. This would open up the possibility of controlled immobilization of proteins, enzymes, DNA or RNA and other molecular systems on spatially ordered nanostructures. In this work, fluorescein was used as an example. Also shown is the possibility of using Raman spectroscopy to analyze material accumulated on such structures. The observed formation of regularly spaced chains of magnetic nanoparticles takes place during the drying process of a thin layer of magnetic liquid placed on an appropriately prepared low-density polyethylene (LDPE) film. [ABSTRACT FROM AUTHOR]

Plastic contamination is commonly reported in urban and rural soils, as well as in fresh and ocean waters. Canada's government has attempted to limit the contamination of single-use plastic by banning the manufacturing and selling of specific types of plastic. In British Columbia, current regulations governing commercial composting state that when compost has less than 1% of its dry weight representing foreign materials (including plastic), it can be sold and used in soils. However, due to the low density of plastic and its potential to break down into microparticles, this amount may be enough to become toxic when used in agricultural soils. This paper studies contamination of plastic in garden soils and summarizes how this can affect the environment with a preliminary examination of a garden soil sample. The examination showed that the garden soil sample contained mainly low-density polyethylene, polyethylene and polypropylene plastics (identified through ATR-FTIR) in oxidized and unoxidized forms that can come from commercial composting and hypothesizes that this plastic could break down into microplastic particles. In order to limit the amount of plastic contamination in agricultural soils, it is necessary to modify current compost regulations in order to treat plastic differently than other foreign materials (glass, metal, wood). [ABSTRACT FROM AUTHOR]

The global problem of microplastics in the environment is "inspiring" scientists to find environmentally friendly and economically viable methods to remove these pollutants from the environment. Advanced oxidation processes are among the most promising methods. In this work, the potential of Fenton, photo-Fenton, and Fenton-like processes for the degradation of microplastics from low-density polyethylene (LDPE), polypropylene (PP), and poly(vinyl chloride) (PVC) in water suspensions was investigated. The influence of three parameters on the efficiency of the degradation process was tested: the pH of the medium (3–7), the mass of added iron (10–50 times less than the mass of microplastics), and the mass of added H2O2 (5–25 times more than the mass of added iron). The effectiveness of the treatment was monitored by FTIR-ATR spectroscopy. After 60-min treatments, the PP microparticles were found to be insensitive. In the Fenton treatment of PVC and the photo-Fenton treatment of LDPE and PVC, changes in the FTIR spectra related to the degradation of the microplastics were observed. In these three cases, the treatment parameters were optimized. It was found that a low pH (3) and a high iron mass (optimal values were 1/12 and 1/10 of the mass of the microplastics for LDPE and PVC, respectively) favored all three. The degradation of LDPE by the photo-Fenton treatment was favored by high H2O2 concentrations (25 times higher than the mass of iron), while these concentrations were significantly lower for PVC (11 and 15 times for the Fenton and photo-Fenton treatment, respectively), suggesting that scavenging activity occurs. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are globally observed in marine as well as freshwater habitats, and laboratory studies have shown that marine organisms can accidentally ingest them. Monitoring the MP ingestion by fish in the environment is very crucial for understanding the risk of consuming MP-contaminated fish for human health. In this study, we investigated MP ingestion in 400 fish individuals from the Veraval Coast, in the state of Gujarat, India. There was 100% MP occurrence in the inedible tissues of fish, and 68% of the analyzed fishes presented MPs in edible tissues. The most dominant MPs based on their size in fishes were 0.05–0.1 mm. One hundred percent presence of only fibres in edible tissue was observed, while in inedible tissue, it was 77%, 20.42% and 2.58% of fibre, fragment and film respectively. The most common MP colour was blue. The predominant polymers were low-density polyethylene (LDPE) followed by polypropylene, high-density polyethylene (HDPE) and polystyrene. This is the first study performed on MPs in marine fishes from this region. Our findings suggest that the abundance of MPs observed in this area is higher than in other states of the country. [ABSTRACT FROM AUTHOR]

Conductive polymer composites (CPCs) with the ability to maintain high conductivity whilst remaining flexible at various operating temperatures and conditions have gained interest as potential materials for electronic interconnect applications. The ability of a polymer matrix to conduct electricity is mainly dependent on the conductive filler loadings as well as the formation of network paths within the CPCs. The main aim of this research work was to establish and understand the correlation between the network structure formation and mechanical properties of linear low-density polyethylene/copper (LLDPE/Cu) and liquid silicone rubber/copper (LSR/Cu) CPCs. Various techniques such as electron microscopy, thermal studies, four-point probe, and tensile testing were employed in this study. Furthermore, selected samples were characterized and tested using synchrotron micro-x-ray fluorescence (XRF) technique and dynamic mechanical analysis (DMA). It was found that the electrical conductivity of the CPCs increased with increasing filler loadings. Addition of Cu filler had a marginal effect on the tensile strength of both LLDPE/Cu and LSR/Cu CPCs. Nevertheless, it was found that the elongation at break for LLDPE/Cu consistently increased with the addition of Cu whereas, for LSR/Cu samples, the elongation at break decreased with the addition of Cu at various loadings. The scanning electron microscopy (SEM) micrographs obtained show that the particles of Cu were closer to one another at higher filler loadings. The data obtained revealed the potential for utilizing CPCs as flexible interconnects suitable for advanced electronic applications. [ABSTRACT FROM AUTHOR]

This paper describes the development of new types of dynamically cross-linked thermoplastic elastomers based on ethylene-propylene-terpolymer rubber and low-density polyethylene, reinforced with plasticized starch and montmorillonite with a chemically modified surface. An octylphenolformaldehyde resin in the presence of stannous chloride dihydrate was used as a vulcanizing agent. The samples were obtained on a Brabender Plasti-Corder mixer, at appropriate temperatures and rotation speeds, using the dynamic vulcanization method and the melt intercalation technique. The mixtures obtained were modeled in the form of plates with standard dimensions using specific molds and a laboratory-scale electrical press. The obtained samples were analyzed from the point of view of the physical-mechanical properties, the melt flow index, as well as from the structural and morphological point of view. It was observed that the characteristics of the samples are influenced by both the composition and the methods of obtaining used. According to the obtained characteristics, the new elasto-plastic materials can be used in fields such as the footwear industry (for the production of: soles, heels, protective boots), in the rubber and plastics industry, the automobile industry, agriculture or construction (when making gaskets, technical items, hoses, etc.). They can be easily processed into different finished products by methods specific to plastics. [ABSTRACT FROM AUTHOR]

The newest method for recycling waste linear low-density polyethylene (LLDPE) is the thermo-catalytic degradation technique known as catalytic pyrolysis. Typically, it is limited by 500–800 °C high temperatures. Catalytic pyrolysis releases toxins and forms harmful carbonized char. The current study is based on exposing wasted LLDPE to different gamma irradiation doses and then pyrolysis in castor oil (150–300 °C). The output product of Ir-(rLLDPE) is turned into another compound with a new structural architecture (sponge-like). SEM analysis confirms conversion, showing sponge-like spicules and layers. Ir-(rLLDPE) is sponge-like with a soft, malleable, absorbent texture. The DSC demonstrates altered thermal properties, with a melting point at 121 °C splitting into two peaks (endothermic at 117 °C and exothermic at 160 °C). The exothermic peaks signify the curing process of the sponge-like material. Ir-(rLLDPE) is assessed as an adsorbent for aqueous oils and solvents. The study examines irradiation doses, pyrolysis temperature, and time on adsorbent capacity. The oil removal obeys the Langmuir isotherm with monolayer adsorption, with a maximum adsorption capacity of 24.75 g/g of waste oil and 43 g/g of 1,1,2,2-tetrachloroethane. Squashing maintains adsorption after 20 reuses. Data shows sponges effectively clean marine oil spills and solvents. [ABSTRACT FROM AUTHOR]

In this study, Silybum marianum extract powder was introduced into low density polyethylene (LDPE) as a primary polyphenolic antioxidant via melt blending method. Two synthetic and commercial polyphenol- and phosphite-based antioxidants (Irganox® 1010 and Irgafos® 168) were also used for comparing the antioxidant efficiency and performance of Silybum marianum extract with commercial ones. A systematic formulation study was achieved by varying the amount of Silybum marianum extract in the range of 0.1–1.0 wt% and the primary:secondary antioxidant ratio. Antioxidant efficiency of Silybum marianum extract was quantified with the oxygen induction time (OIT) and oxidation onset temperature values determined by thermal analysis in a differential scanning calorimeter depending on the compositional variations. Some physical properties of specimens such as transparency, color coordinates, contact angle, and degree of crystallinity values were also examined. It was found that 0.2 wt% of Silybum marianum extract and 0.2 wt% of Irgafos® 168 loaded sample showed an OIT value of 22 min. at 210 °C that could be regarded as a very successful commercial potential. Increasing amount of Silybum marianum extract and Irgafos® 168 significantly improved the oxidation stability of polyethylene under isothermal and non-isothermal conditions. It was also found that introducing Silybum marianum extract, even the loading content of 1.0 wt%, did not alter the transparency and physical properties of LDPE. It has been concluded that Silybum marianum extract can be successfully used as a natural antioxidant in polyolefins and these samples could be used in packaging film applications. [ABSTRACT FROM AUTHOR]

The research examined the ability of each treatment to recover a known quantity of particles and the impact on identifying polymer type using a microscope. By conducting extensive research on the changes induced in the chemical structures and morphologies of microplastics (MPs) there is potential for enhancing the detection and analysis of MPs by incorporating pre-treatment methods in the future. When treating environmental matrices with high organic content, chemical digestion treatment is required to get rid of microplastics and release particles. This type of treatment involves using a range of chemical agents, including acids, bases, and oxidizing agents. Unfortunately, there has been limited research into the chemical resistance of various types of microplastics to these substances. To address this issue, a study was conducted to examine the chemical resistance of four species of microplastics high-density polyethylene (HD-PE), low-density polyethylene (LD-PE), polypropylene (PP) and polyethylene terephthalate (PET) to hydrogen peroxide (H2O2), potassium hydroxide (KOH), nitric acid (HNO3) and acetic acid (CH3COOH). The results showed that acidic and alkaline substances were the most destructive to microplastics, while oxidative reagents resulted in fewer changes to plastic properties. These findings provide valuable insights into the properties of MPs and their response to strong acids, bases and oxidizing agents, which can serve as a reference for future studies on MP pre-treatment. In addition, used as a guideline to update current protocols and ensure that microplastics can be treated without causing damage. Highlights: The purpose of this study was to investigate the effects of different chemical digestion protocols, including acidic, oxidative, and alkaline reagents, on the physical and chemical properties of microplastics. Before processing and analyzing samples, it is critical to assess chemical digestion protocols to ensure that microplastics are recovered optimally. Based on the observations of different types of microplastics and methods tested, oxidative digestion at room temperature (20–23 °C) appears to be the most appropriate for digestion, but it can be destructive over an extended period. Selective processing conditions that eliminate certain materials may result in incomplete assessments of the occurrence, types, sources, and impacts of microplastics. The properties related to digestion can vary depending on the polymer type, so further research is needed on the specific polymer types relevant to each study. [ABSTRACT FROM AUTHOR]

Hydrocracking catalysis is a key route to plastic waste upgrading, but the acid site‐driven C−C cleavage step is relatively sluggish in conventional bifunctional catalysts, dramatically effecting the overall efficiency. We demonstrate here a facile and efficient way to boost the reactivity of acid sites by introducing Ce promoters into Pt/HY catalysts, thus achieving a better metal‐acid balance. Remarkably, 100 % of low‐density polyethylene (LDPE) can be converted with 80.9 % selectivity of liquid fuels over the obtained Pt/5Ce‐HY catalysts at 300 °C in 2 h. For comparison, Pt/HY only gives 38.8 % of LDPE conversion with 21.3 % selectivity of liquid fuels. Through multiple experimental studies on the structure‐performance relationship, the Ce species occupied in the supercage are identified as the actual active sites, which possess remarkably‐improved adsorption capability towards short‐chain intermediates. [ABSTRACT FROM AUTHOR]

It is essential to develop a mechanism for lowering the molecular weight of polyolefins to achieve biodegradation in seawater. In this study, a polypropylene/polylactic acid blend sample was first subjected to photodegradation pretreatment, and it was confirmed that in pure water, the acid generated promotes the polypropylene degradation (autoxidation), while in alkaline seawater, the promotion was inhibited by a neutralization reaction. In the autoxidation of polyolefins in alkaline seawater, aqueous Cl− was also the inhibitor. However, we found that autoxidation could be initiated even in seawater by lowering the pH and using dissociation of ClOH (called blister degradation). The blister degradation mechanism enabled autoxidation, even in seawater, by taking advantage of the ability of diatoms to secrete transparent exopolymer particles (TEP) to prevent direct contact between the surface layer of polyolefins and alkaline seawater. We named blister degradation in seawater with diatoms as bio-blister degradation and confirmed its manifestation using linear low-density polyethylene (LLDPE)/starch samples by SEM, IR, DSC and GPC analysis. [ABSTRACT FROM AUTHOR]

The insulation layer of deep-sea optoelectronic composite cables in direct contact with high-pressure and highly corrosive seawater is required for excellent water resistance, environmental stress cracking resistance (ESCR), and the ability to withstand high DC voltage. Although high-density polyethylene (HDPE) displays remarkable water resistance, it lacks sufficient resistance to environmental stress cracking (ESCR). This article is based on a blend modification approach to mixing HDPE with different vinyl copolymer materials (cPE-A and cPE-B). The processing performance and mechanical properties of the materials are evaluated through rheological and mechanical testing. The materials' durability in working environments is assessed through ESCR tests and water resistance experiments. Ultimately, the direct current electrical performance of the materials is evaluated through tests measuring space charge distribution, direct current resistivity, and direct current breakdown strength. The results indicate that, in the polyethylene blend system, the rheological properties and ESCR characteristics of HDPE/cPE-A composite materials did not show significant improvement. Further incorporation of high melt index linear low-density polyethylene (LLDPE) material not only meets the requirements of extrusion processing but also exhibits a notable enhancement in ESCR performance. Meanwhile, copolymerized polyethylene cPE-B, with a more complex structure, proves effective in toughening HDPE materials. The material's hardness significantly decreases, and when incorporating cPE-B at a level exceeding 20 phr, the composite materials achieve excellent ESCR performance. In a simulated seawater environment at 50 MPa, the water permeability of all co-modified composite materials remained below 0.16% after 120 h. The spatial charge distribution and direct current resistivity characteristics of the HDPE, cPE-A, and LLDPE composite systems surpassed those of the HDPE/cPE-B materials. However, the HDPE/cPE-B composite system exhibited superior dielectric strength. The application of composite materials in deep-sea electro–optical composite cables is highly promising. [ABSTRACT FROM AUTHOR]

Background: Among the polyhydroxyalkanoate (PHA), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] [P(3HB-co-3HHx)] is reported to closely resemble polypropylene and low-density polyethylene. Studies have shown that PHA synthase (PhaC) from mangrove soil (PhaCBP-M-CPF4) is an efficient PhaC for P(3HB-co-3HHx) production and N-termini of PhaCs influence its substrate specificity, dimerization, granule morphology, and molecular weights of PHA produced. This study aims to further improve PhaCBP-M-CPF4 through N-terminal truncation. Results: The N-terminal truncated mutants of PhaCBP-M-CPF4 were constructed based on the information of the predicted secondary and tertiary structures using PSIPRED server and AlphaFold2 program, respectively. The N-terminal truncated PhaCBP-M-CPF4 mutants were evaluated in C. necator mutant PHB−4 based on the cell dry weight, PHA content, 3HHx molar composition, molecular weights, and granule morphology of the PHA granules. The results showed that most transformants harbouring the N-terminal truncated PhaCBP-M-CPF4 showed a reduction in PHA content and cell dry weight except for PhaCBP-M-CPF4 G8. PhaCBP-M-CPF4 G8 and A27 showed an improved weight-average molecular weight (Mw) of PHA produced due to lower expression of the truncated PhaCBP-M-CPF4. Transformants harbouring PhaCBP-M-CPF4 G8, A27, and T74 showed a reduction in the number of granules. PhaCBP-M-CPF4 G8 produced higher Mw PHA in mostly single larger PHA granules with comparable production as the full-length PhaCBP-M-CPF4. Conclusion: This research showed that N-terminal truncation had effects on PHA accumulation, substrate specificity, Mw, and granule morphology. This study also showed that N-terminal truncation of the amino acids that did not adopt any secondary structure can be an alternative to improve PhaCs for the production of PHA with higher Mw in mostly single larger granules. [ABSTRACT FROM AUTHOR]

The main objective of this study was to discover new packaging materials that could integrate one of the most expected properties, such as UV protection, with a self-cleaning ability defined as photocatalytic performance. Accordingly, new hybrid additives were used to transform LDPE films into materials with complex performance properties. In this study, titanium dioxide–lignin (TL) hybrid systems with a weight ratio of inorganic to organic precursors of 5-1, 1-1, and 1-5 were prepared using a mechanical method. The obtained materials and pristine components were characterized using measurement techniques and research methods, such as Fourier-transform infrared spectroscopy (FTIR), thermal stability analysis (TGA/DTG), measurement of the electrokinetic potential as a function of pH, scanning electron microscopy (SEM), and particle size distribution measurement. It was found that hydrogen bonds were formed between the organic and inorganic components, based on which the obtained systems were classified as class I hybrid materials. In the next step, inorganic–organic hybrid systems and pristine components were used as fillers for a low-density polyethylene (LDPE) composite, 5 and 10% by weight, in order to determine their impact on parameters such as tensile elongation at break. Polymer composites containing titanium dioxide in their matrix were then subjected to a test of photocatalytic properties, based on which it was found that all materials with TiO2 in their structure exhibit photocatalytic properties, whereby the best results were obtained for samples containing the TiO2–lignin hybrid system (1-1). The mechanical tests showed that the thin sheet films had a strong anisotropy due to chill-roll extrusion, ranging from 1.98 to 3.32. UV–Vis spectroscopy revealed four times higher light absorption for composites in which lignin was present than for pure LDPE, in the 250–450 nm range. On the other hand, the temperature at 5% and 30% weight loss revealed by TGA testing increased the highest performance for LDPE/TiO2 materials (by 20.4 °C and 8.7 °C, respectively). [ABSTRACT FROM AUTHOR]

Development of biobased aliphatic polyesters with better mechanical (tensile) properties in film has attracted considerable attention. This report presents the synthesis of soluble network biobased aliphatic polyesters by acyclic diene metathesis (ADMET) polymerization of bis(undec-10-enyl)isosorbide diester [M1, dianhydro-D-glucityl bis(undec-10-enoate)] in the presence of a tri-arm crosslinker [CL, glycerol tris(undec-10-enoate)] using a ruthenium–carbene catalyst, and subsequent olefin hydrogenation using RhCl(PPh3)3. The resultant polymers, after hydrogenation (expressed as HCP1) and prepared in the presence of 1.0 mol% CL, showed better tensile properties than the linear polymer (HP1) with similar molecular weight [tensile strength (elongation at break): 20.8 MPa (282%) in HP1 vs. 35.4 MPa (572%) in HCP1]. It turned out that the polymer films prepared by the addition of CL during the polymerization (expressed as a 2-step approach) showed better tensile properties. The resultant polymer film also shows better tensile properties than the conventional polyolefins such as linear high density polyethylene, polypropylene, and low density polyethylene. [ABSTRACT FROM AUTHOR]

In this paper, a series of ethylene propylene diene monomer/low density polyethylene (EPDM/LDPE) composites with the shape memory effect (SME) are prepared by polymer blending method. The cross-link structure and crystallization are regulated by the impact of thermodynamic factor and content of peroxide, and the influence on SME is also investigated. The results demonstrate that the interfacial adhesion originates from the good interfacial compatibility and interfacial grafting reaction between the phases, and the cross-linked chemical structure improves interfacial adhesion and forms abundant tiny LDPE crystals, which plays a crucial role in exploring the SME and improving the mechanical performance of EPDM/LDPE composites. A balanced state between the mechanical properties and SME is achieved when dicumyl peroxide content is 1 wt.%; the tensile strength and elongation at break reach 19.2 MPa and 1499%, respectively, while the shape fixation ratio (Rf) and shape recovery ratio (Rr) are ~ 99% and ~ 85%, respectively. [ABSTRACT FROM AUTHOR]

Ultraviolet light (UV) irradiation crosslinked linear low‐density polyethylene (LLDPE)/ethylene propylene diene monomer (EPDM) composites with different blending ratios were prepared using benzophenone (BP) as photoinitiator and triallyl isocyanurate (TAIC) as crosslinking agent. The irradiation time was determined, the effects of rubber‐plastic ratio on the crystallization behaviors, mechanical properties, crosslinking properties and electrical properties of LLDPE/EPDM composites were investigated. The results show that with the increase of EPDM content, the crystalline structure of LLDPE/EPDM composite become looser and the crystallinity decreased. The blending of EPDM and LLDPE results in two different aggregation states of the same crystalline form. With the increase of LLDPE content, the crosslinking efficiency, tensile strength, and energy storage modulus show a significant upward trend. When two polymers simultaneously exist in the material, if the difference between the contents of two polymers is large, the breakdown strength of the composite is relatively lower. The relaxation polarization of LLDPE/EPDM at low frequencies increases with the content of EPDM, thus leading to the increase of loss factor at low frequencies. A novel UV crosslinked modified EPDM insulating material with high production efficiency and improved insulation performances has been developed for use as an insulating layer for flexible power cables. [ABSTRACT FROM AUTHOR]