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In the present study, we investigated the possibility of value-added recycling of ultrafine ground tire rubber (uGTR) produced from water jet milling, with an average particle size of a few tens of microns. Our goal was to compare the properties of blends with different uGTR and conventional fine ground tire rubber (fGTR) contents prepared by blending with low-density polyethylene (LDPE). We also aimed to explore the property changes caused by the larger specific surface area due to the size effect. Samples were prepared with a hydraulic press after internal mixing. In the case of ground tire rubber (GTR) filled mixtures, the tensile properties showed rubber-like characteristics: with a significant decrease in modulus, elongation at break remained high, and tensile strength slightly decreased. The fracture surfaces of the samples were analyzed by scanning electron microscopy (SEM), wherein the case of materials made with uGTR showed better adhesion between the phases. In order to investigate the interfacial adhesion between the GTR and LDPE, we performed dynamic mechanical thermal analysis (DMTA). The glass transition peak of the uGTR shifted to a higher temperature and the storage modulus was higher than in the case of samples containing fGTR. Finally, we determined the Shore D hardness of the materials, which decreased with increasing GTR content, but hardness was greater in the case of uGTR samples. The better mechanical properties of blends containing uGTR were explained by better interfacial adhesion between the two phases due to the significantly higher specific surface area compared to fGTR.

A new era is rising in food packaging and preservation, with a consequent focus on transition to “greener” and environmentally friendly techniques. The environmental problems that are emerging nowadays impose use of natural materials for food packaging applications, replacement of chemical preservatives with natural organic extractions, such as essential oils, and targeting of new achievements, such as further extension of food shelf-life. According to this new philosophy, most of the used materials for food packaging should be recyclable, natural or bio-based, and/or edible. The aim of this work was to investigate use and efficiency of a novel food packaging developed based on commercial LDPE polymer incorporated with natural material halloysite impregnated with natural extract of thyme oil. Moreover, a direct correlation between the stiff TBARS method and the easiest heme iron measurements method was scanned to test food lesions easier and faster. The result of this study was development of the LDPE/10TO@HNT film, which contains the optimum amount of a hybrid nanostructure and is capable to be used as an efficient active food packaging film. Furthermore, a linear correlation seems to connect the TBARS and heme iron measurements.

It is of significant concern that the buildup of non-biodegradable plastic waste in the environment may result in long-term issues with the environment, the economy and waste management. In this study, low-density polyethylene (LDPE) was compounded with different contents of poly(butylene succinate) (PBS) at 10–50 wt.%, to evaluate the potential of replacing commercial plastics with a biodegradable renewable polymer, PBS for packaging applications. The morphological, mechanical and thermal properties of the LDPE/PBS blends were examined in relation to the effect of polyethylene–graft–maleic anhydride (PE–g–MA) as a compatibilizer. LDPE/PBS/PE–g–MA blends were fabricated via the melt blending method using an internal mixer and then were compression molded into test samples. The presence of LDPE, PBS and PE–g–MA individually in the matrix for each blend presented physical interaction between the constituents, as shown by Fourier-transform infrared spectroscopy (FTIR). The morphology of LDPE/PBS/PE–g–MA blends showed improved compatibility and homogeneity between the LDPE matrix and PBS phase. Compatibilized LDPE/PBS blends showed an improvement in the tensile strength, with 5 phr of compatibilizer providing the optimal content. The thermal stability of LDPE/PBS blends decreased with higher PBS content and the thermal stability of compatibilized blends was higher in contrast to the uncompatibilized blends. Therefore, our research demonstrated that the partial substitution of LDPE with a biodegradable PBS and the incorporation of the PE–g–MA compatibilizer could develop an innovative blend with improved structural, mechanical and thermal properties.

At present, there is a vital need for river water purification by developing new approaches to eliminate bacterial biofilms, textile dyes, and Low-Density Polyethylene (LDPE) plastics that pose severe threats to human and environmental health. The current work put forward the construction of an eco-friendly green strategy to synthesize zinc oxide nanoparticles (ZnO NPs) using areca nut (Areca catechu) extract and their application to tackle the challenges in water purification. Prepared biogenic NPs were characterized by X-ray diffraction analysis (XRD), Fourier Transform Infra-Red (FT-IR), Energy Diffraction Spectroscopy (EDS), Scanning Electronic Microscopy (SEM), Transmission Electron Microscopy (TEM) analysis, confirmed the spherical shape in 20 nm and UV–vis spectroscopy. The characteristic absorption band exhibited at 326 nm confirmed the formation of ZnO NPs using UV–vis spectroscopy. Among all the tested bacterial pathogens, the E. coli at 50 µg/mL concentration showed the highest inhibition of biofilm activity, followed by the highest growth curve, cellular leakage, and potassium ion efflux. The ZnO NPs observed with photo-degradation of Rhodamine-B (Rh-B), Methylene Blue (MB), and Nigrosine dyes under sunlight irradiation at different time intervals. Finally, the photocatalytic activity of LDPE-ZnO NPs nanocomposite film showed the highest degradation under solar light irradiation were confirmed through photo-induced weight loss, SEM, FTIR, and MALDI-TOF analysis. This study demonstrates ZnO NPs exhibit efficacy against biofilm formation, degradation of photocatalytic textile dyes, and low-density LDPE film under solar light irradiation, which can be a step forward in water purification.

Temperature, concentrations and mixing techniques are often the small details that make the difference in scientific advances and bridge the gap between a purely scientific approach and a purely practical one. This work first focuses on the thermal behavior of two blowing agents, widely used in the foam industry, namely sodium bicarbonate, citric acid and their mixtures, using a TGA-DSC. The second part of this work consists in preparing blends with low-density polyethylene at different concentrations and in determining the best combinations that will make it possible to prepare new blends based on optimal concentrations and then to study their physico-chemical properties. This study showed that sodium bicarbonate gives off more gas, since an increase in diameter of nearly 60% was obtained with 2 phr of the later, and nearly 30% with 1 phr of citric acid. However, for mixtures based on optimal concentrations, a synergy was obtained for the 60/40 and 50/50 mixture. Mixing the optimal concentrations also resulted in denser cells with finer and more regular sizes.

Dissolved oxygen (DO) level is of capital importance in the field of environmental monitoring, food fermentation, industrial production, and clinical medicine. Optical oxygen sensors with high sensitivity, accuracy, stability, and anti-jamming capability for DO content detection have provoked scientists’ attention in recent years. In this work, we selected platinum octaethylporphine (PtOEP), low-density polyethylene (LDPE), and high-density polyethylene (HDPE) as the fluorescent indicator and matrix materials, respectively. Porous LDPE/PtOEP and HDPE/PtOEP oxygen-sensing films were constructed by incorporating PtOEP in PE via the phase-separation method. The optimum parameters were obtained as follows: the concentrations of LDPE and HDPE solutions were 0.010 mg/L, and PtOEP was 8 μg. Based on the above study, the effects of different kinds of PE on the performance of the oxygen-sensing film were studied in detail, finding that the LDPE/PtOEP oxygen-sensing film had better photostability and could measure the DO concentrations of several water samples accurately.

The aim of this study was to produce crosslinked low-density polyethylene (LDPE) composites using peroxide and octavinyl polyhedral oligomeric silsesquioxane (OvPOSS) and to examine the shape memor...

Blends of a poly(butylene adipate-co-terephthalate) (PBAT) and a low density polyethylene (LDPE) (80 wt%/20 wt%) were prepared through a twin screw extruder while incorporating 3 wt% Cloisite 30B (C30B) nanoclay that possessed a much higher affinity with PBAT. The blends were processed through three melt mixing strategies: ( i) direct mixing of all three components, (ii) mixing C30B and PBAT followed by mixing with LDPE, and (iii) mixing C30B and LDPE followed by mixing with PBAT. The rheological properties of each system were determined in small amplitude oscillatory shear (SAOS) experiments. The migration of C30B nanoparticles from the LDPE minor phase towards the PBAT matrix was then monitored in the blend nanocomposites prepared through strategy (iii) via SAOS time sweep experiments. It was firstly understood that the C30B migration could be detected during time sweep SAOS experiments. The migration time was observed to be frequency dependent due to the smaller length scales probed at larger frequencies. Such migration occurred even faster when the SAOS time sweep experiments were conducted at a higher temperature due to the viscosity reduction.

Despite the enormous environmental damage caused by plastic waste, it makes up over one-third of globally produced plastics. Polyethylene (PE) wastes have low recycling but high production rates. Towards the construction of ionic solar cells from PE, the present work describes the loading of a bioactive photoacid phycocyanobilin (PCB) dye from the pigment of Spirulina blue–green algae (as a natural resource) on low-density polyethylene (LDPE) plastic film. Dyeing was confirmed by X-ray photoelectron spectroscopy (XPS). Upon excitation of the Soret-band (400 nm), the photoluminescence (PL) spectra of PCB in neat solvents revealed two prominent emission peaks at 450–550 and 600–700 nm. The first band assigned to bilirubin-like (PCBBR) species predominated the spectral profile in the highly rigid solvent glycerol and upon loading 0.45 % (w/w) of the dye on plastic. The photoluminescence excitation (PLE) spectra of PCB for the second region (Q-band) at 672 nm in the same solvents confirmed the ground state heterogenicity previously associated with the presence of PCBA (neutral), PCBB (cationic), and PCBC (anionic) conformers. Time-resolved photoluminescence (TRPL) measurements induced via excitation of all PCB species at 510 nm in methanol revealed three-lifetime components with τ1 = ~0.1 ns and τ2 = ~2 ns associated with PCBBR species and τ3 = ~5 ns pertinent to the long-living photoproduct X*. Decay-associated spectra (DAS) analysis of the photoluminescence transient spectra of the final dyed films in the solid-state confirmed the improved generation of the long-living photoproduct as manifested in a significant increase in the PL intensity (~100-fold) and lifetime value (~90 ns) in the Q-region upon loading 6.92 % (w/w) of the dye on plastic. The photoproduct species were presumably assigned to the deprotonated PCB species, suggesting improved ionic mobility. The potential implementation of the PCB-sensitized PE solid wastes for the fabrication of ionic solar cells is discussed.

Bioblend films composed of polyvinyl alcohol/carboxymethyl cellulose/citric acid/glycerol PVA/CMC/CA/Glyc were prepared by the casting method. The effect of different contents of citric acid and glycerol as cross-linker and plasticizer, respectively, on the properties was evaluated. The properties of the bioblend films were determined using FTIR spectroscopy, mechanical tests, TGA and XRD. The best properties were observed in PVA/CMC/CA/Glyc bioblend film with composition (1:1:1/30 vol %), which was characterized by lower swelling behavior, higher tensile properties and good thermal stability. The use of citric acid (CA) as an inexpensive natural cross-linker enhanced the water resistance of the prepared bioblend film at composition of (1:1:1/30 vol %). The increase of citric content more than 1% ratio leads to the formation of bioblend with a higher mobility of chains, which resulted in a higher swelling behavior that is not recommended in some applications such as packaging materials. Glycerol (Glyc) is found to be a good plasticizer that improved mechanical, thermal and water resistance properties via the formation of hydrogen bonding within the bioblend matrix. Further modifications of the prepared bioblend film were obtained by irradiation with gamma rays at different doses. It is found that at irradiation dose of 10 kGy, the thermal and mechanical properties improved and water resistance increased. The improved mechanical and thermal properties of the selected PVA/CMC/CA/Glyc bioblend film with composition (1:1:1/30 vol %) were compared with LDPE and PP commercial packaging films, and they were found to be competitive to these films.

This investigation highlights effective technology to convert crystalline silicon photovoltaic solar panel waste to composite products. The main problem with recycling photovoltaic modules is to economically separate and extract the materials in the laminated structure. This investigation was attempted to recycle c-Si photovoltaic modules using an unconventional method in which the cumbersome process of separating the materials in the module is avoided altogether. The aluminium frame, outer glass and junction box are removed mechanically and the rest of the c-Si PV module waste is powdered and blended with recycled polypropylene (PP) and Low Density Polyethylene (LDPE) each to make compression moulded tiles. A total of six compression moulded tiles were made. Three tiles from each base material blended in three blend ratios (0%, 10% and 20%) with the powdered PV module waste. The tensile strengths of the tiles were tested and compared. The results prove that tiles made with recycled PP as a base material show very low tensile strength. However, recycled tiles made by blending with LDPE show appreciable tensile strength of more than 8 MPa. These tiles may be used to make furniture.

The dynamic rheological behavior of polypropylene (PP)/low-density polyethylene (LDPE) blending melts at 210 °C and 230 °C was measured by small-amplitude oscillatory shear mode on a rotational rheometer. The complex viscosity and dynamic modulus of pure PP are higher than those of pure LDPE at low frequency. For the blends with dispersion morphologies, Palierne model is applied to fit the storage modulus data and the model almost underestimates the data since most of the experimental dynamic modulus of the blends lay between that of pure PP and pure LDPE. While Lee and Park model predicts the dynamic storage data well for the PP/LDPE blends 90/10, 10/90 and 70/30 blends. For the 30/70 blend, this model describes the data much closer than Palierne model and a little deviation occurs at low frequency. The comparison between the two models’ fitting results indicates interaction among dispersed droplets should be considered.

Plastic waste has been growing every year, and as a result, environmental concern has been a topic of much attention. Many properties of plastics, such as their lightweight, durability, and versatility, are significant factors in achieving sustainable development. The exponential increase of plastic production produces every year approximately 100 million tons of waste plastic, which could be converted into hydrocarbon fuels by employing a process appropriately called pyrolysis. Pyrolysis, which is thermal or catalytical, can be performed under different experimental conditions that affect the type and amount of product obtained. With the pyrolysis process, products can be obtained with high added value, such as fuel oils and feedstock for new products. In this study, magnesium silicate (MgO3Si) and Cloisite 30B were used as catalysts for the decomposition of different plastics, and the results were compared with the zeolite catalyst. In the case of high-density polyethylene (HDPE), the oil yield with a zeolite catalyst was found to be 71%, whereas with MgO3Si and Cloisite 30B, this was 68% and 67%, respectively. Zeolite produced better results in the decomposition of polypropylene (PP) compared to MgO3Si and Cloisite 30B. Fourier-transform infrared spectroscopy (FTIR), and gas chromatography (GC) were conducted in this work. The spectra results for all samples were consistent and in the fuel range.

Generally, polyamide cannot be used as film blowing material because of its unsuitable properties. In this study, polyamide 6 clay nanocomposite (cPA) and styrene maleic anhydride copolymer (SMA) were mixed in various ratios for the preparation of modified polyamide 6 clay nanocomposite SxcPAy resins by reactive extrusion. The S1cPA14 resin was blended with recycled maleic anhydride polyamide (rPA) to form the (S1cPA14)x rPAy resins. Finally, they were mixed with LDPE in 1:9 ratio to afford (SxcPAy)1LDPE9 and ((S1cPA14)x rPAy)1LDPE9 resins, respectively, followed by film blowing and the analyses of the physicochemical properties of resins. The FTIR spectrum illustrated that the C=O symmetric and asymmetric absorption fingerprint peaks in the anhydride (-OC-O-CO-) group of SMA disappeared and the new characteristic absorption peak of-CO-N-CO- of imides was observed. The anhydride functional group of SMA underwent reactive extrusion with the terminal amino group of cPA to generate the imides structure. The thermal properties showed that the glass transition temperature and crystallinity of SxcPAy and (S1cPA14)x rPAy resins increased with increasing SMA and S1cPA14 contents. The Tg (85.4.0°C) of (S1cPA14)12 rPA1 resin were enhanced significantly, with 30°C higher than cPA. In terms of tensile mechanical properties, S1cPA14 test pieces demonstrated the highest Young’s modulus and tensile strength. After mixing with LDPE, the tensile mechanical properties of (SxcPAy)1LDPE9 and ((S1cPA14)x rPAy)1LDPE9 resins and films were both higher than that of LDPE. ((S1cPA14)12 rPA1)1LDPE9 film shown the best tensile properties and barrier performance compared with other films due to the optimal rPA content could assisted SMA as a better compatibilizer to improve the dispersion and compatibility of cPA in HDPE. It was worth noting that (SxcPAy)1LDPE9 and ((S1cPA14)x rPAy)1LDPE9 resins were formed by film blowing at the processing temperature of 140°C followed by successful preparation of the film.

The impact of a small amount of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) on the thermomechanical and electrical properties of blends comprising low-density polyethylene (LDPE) and isotactic polypropylene (PP) is investigated. SEBS is found to assemble at the PP:LDPE interface as well as within isolated PP domains. The addition of 10 wt% SEBS significantly increases the storage modulus between the melting temperatures of the two polyolefins, 110 and 160°C, and results in improved resistance to creep during both tensile deformation as well as compression. Furthermore, the ternary blends display a very low direct-current (DC) conductivity as low as 3.4 × 10 S m at 70°C and 30 kV mm , which is considerably lower than values measured for neat LDPE. The here presented type of ternary blend shows potential as an insulation material for high-voltage direct current power cables.

The inappropriate disposal of plastic waste cause serious environmental problems. Nowadays, alternative processes are being studied for the sustainable reutilization of plastics. One of these options is the cracking into shorter liquid hydrocarbon fractions, while maintaining its basic chemical structure. The energetic potential from the original plastics structure remains and the fractions can be used as fuels and chemical precursors. This research addresses the kinetic study of thermal cracking of polypropylene (PP) and high- and low-density polyethylene (HDPE and LDPE) in a batch reactor. The kinetics of the reaction can be described as a first-order rate with the lowest activation energy using PP, followed by HDPE and LDPE with values of 367.28 kJ/mol, 453.37 kJ/mol and 457.96 kJ/mol, respectively. The yield obtained for the liquid fraction is highest for LDPE, with a value of 72% at 390°C, followed by HDPE and LDPE with 69% and 62% at 375°C. The liquid fractions obtained from the process were characterized according to ASTM standards, obtaining that LDPE and HDPE fractions have similar properties to diesel, while PP is closer to gasoline. The fractions were also analyzed by means of gas chromatography identifying the main products of the reaction and establishing a possible reaction mechanism.

The rheological behaviors of low-density polyethylene doped with additives (PEDA) determine the dynamic extrusion molding and structure of high-voltage cable insulation. However, the coupling effect of additives and molecular chain structure of LDPE on the rheological behaviors of PEDA is still unclear. Here, for the first time, the rheological behaviors of PEDA under uncross-linked conditions are revealed by experiment and simulation analysis, as well as rheology models. The rheology experiment and molecular simulation results indicate that additives can reduce the shear viscosity of PEDA, but the effect degree of different additives on rheological behaviors is determined by both chemical composition and topological structure. Combined with experiment analysis and the Doi–Edwards model, it demonstrates that the zero-shear viscosity is only determined by LDPE molecular chain structure. Nevertheless, different molecular chain structures of LDPE have different coupling effects with additives on the shear viscosity and non-Newtonian feature. Given this, the rheological behaviors of PEDA are predominant by the molecular chain structure of LDPE and are also affected by additives. This work can provide an important theoretical basis for the optimization and regulation of rheological behaviors of PEDA materials used for high-voltage cable insulation.

Bimetallic (Zn/Al) and trimetallic (Mg,Zn/Al) layered double hydroxides (LDHs) intercalated with nitrate were synthesized by the coprecipitation method and used as precursors to obtain LDHs intercalated with the organic anions 4–4′-diamino-2,2′-stilbenedisulfonate and ortho-phthalate through anion exchange reactions. The materials were used as fillers in different ratios in low-density polyethylene (LDPE) to obtain polymer nanocomposites by extrusion-injection molding. The layered materials were characterized by several instrumental techniques, and the mechanical properties of the nanocomposites were evaluated. The samples were exposed to thermo-oxidative conditions at 60 and 90 °C for 1194 h, and the degradation process of the polymer nanocomposites was studied by measurements of hardness, weight loss and oxidation index. Results showed that trimetallic and bimetallic LDH had a notable effect on the LDPE nanocomposites’ degradation, depending on the intercalated anion. Both systems showed potential use as environmentally friendly stabilizers of polymeric matrices, reducing material damage induced by heat and oxidation, increasing the lifetime of the material and lowering the environmental impact.

In this work, the effect of the linear low-density polyethylene (LLDPE) containing 1-butene or 1-hexene α-olefin short-chain branching (SCB) and low-density polyethylene (LDPE) containing long-chain branching (LCB) on the rheological properties of high-density polyethylene (HDPE)/LLDPE and HDPE/LDPE blends was investigated. The neat polymers and the blends were characterized by torque rheometry and rheological measurements under dynamic oscillatory shear flow. From torque rheometry analysis, an increase in the viscosity of HDPE/LLDPE blends with the increase in LLDPE content was observed. The inverse was observed for HDPE/LDPE blend, where the viscosity decreased with the increase in the LDPE content. Rheological measurements showed an increase in the complex viscosity of the HDPE/LLDPE and HDPE/LDPE blends with the increase in the LLDPE or LDPE content. HDPE/LDPE blends showed a strong shear-thinning behavior due to the presence of LCB in LDPE. Similar rheological behavior was observed for HDPE/LLDPE blends containing 1-butene and 1-hexene SCB. Cole–Cole, Han plots, and van Gurp–Palmen plots indicated miscibility between HDPE and LLDPE and immiscibility between HDPE and LDPE.

The study covered the synthesis of low density polyethylene-graft-maleic anhydride (LDPE-g-MA) and investigated its influence as a compatibilizer for LDPE/polyamide 6 (PA6) blend. LDPE-g-MA characterized by FTIR spectroscopy. Melt blends of LDPE and PA6 which contain 0, 2, 4, 6, 8 and 10 phr of LDPE-g-MA were prepared using a Brabender Plasti-corder and characterized by scanning electron microscope (SEM). The static mechanical, water absorption and dynamic mechanical properties of the LDPE/PA6 blends were reported. The study deduced the optimum content of LDPE-g-MA in LDPE/PA6 blends is 8 phr for morphological properties, flexural strength, tensile strength, flexural modulus, E-modulus, impact strength, water absorption percentage and dynamic mechanical properties. The results demonstrated the possibility of using the LDPE/LDPE-g-MA/PA6 (80/8/20) blend in various industrial applications for LDPE such as the manufacture of products made of plastic and in packaging goods.

The use of immiscible polymers blends is highly prevalent worldwide in view of their unique properties. Nevertheless, the main technical obstacle in the way of developing novel polymers blends remains the effective compatibilization between their components. In this work, reactive compatibilization blends consisting of thermoplastic corn starch/low density polyethylene (TPCS)/LDPE and thermoplastic corn starch/linear low density polyethylene (TPCS)/LLDPE with different portions of polyethylene-grafted-maleic anhydride (PE-g-MA) as compatibilizer were prepared. The novelty of this study is that commercial PE and starches from the local market were used to determine the critical concentration of PE-g-MA needed to attain the best blend properties. FTIR study proved that in the blends containing 7% of compatibilizer, all the available maleic anhydride groups in the PE-g-MA had reacted with the hydroxyl groups of the starch forming new ester bonds. The MFI measurements showed that when the compatibilizer was added, the melt flow index of the blend decreases down to 7% of PE-g-MA and when more compatibilizer was added no more change in MFI was noticed because of the cessation of ester bonds forming. The thermal stability improved with the increase of (PE-g-MA) concentration till 7% then it decreased again at 9%. The elongation at break and the tensile strength reached the highest value with 7 wt % of PE-g-MA.

The development of antimicrobial LDPE films containing ferula hydroalcoholic leaf and gum extracts was investigated. At the end of the 10th day, the highest rate of the released flavonoid compounds was related to the films containing 5% leaf extracts (PE-Leaf-5, 3663.71 µg/g) for 95% ethanol simulation at 60 °C. The carvacrol acetate and β-Elemene in the 95% ethanol simulation containing PE-Leaf and α-bisabolol in the simulation including a film containing gum extract (PE-Gum) were not found. The highest effect of the antimicrobial property was related to the PE-Leaf films, but the highest rate of release of the compounds was related to the PE-Gum films. At the end of day 14th, the growth rate of Aspergillus niger in the presence of the PE-Leaf-5 and PE-Gum-5 films was reduced 3.23 and 3.72 logarithmic cycles, respectively. At the end of day 10th at 4oC, the total fungi count has reduced 0.89 and 0.85 logarithmic cycles in the dough samples packed with PE-Leaf and PE-Gum films, respectively while after 6 days preservation at 25°C, they reduced 1.51 and 1.68 logarithmic cycles, respectively. It seems the development of antimicrobial films containing ferula bioactive compounds can be effective in prolonging the shelf life of the foods.

The current trend in deteriorating mechanical performance of green polymeric-based materials has made it essential for designers to establish more reliable and sustainable bio-products. Here, the mechanical performance of Jordanian lignocellulosic olive fibers in polymeric-based composites has been methodically investigated. The outcomes of different reinforcement conditions on the desired mechanical performance of the olive leaf’s lignocellulosic fibers with low-density polyethylene (LDPE) composites have been examined, including the properties of tensile strength, tensile modulus, mechanical strain, impact strength, and the intensity per composite volume. This has been accomplished to determine the optimum reinforcement condition for the desired mechanical behavior as well as to establish the performance deterioration and enhancement trends of such bio-materials in a more consistent manner. The results signify that lignocellulosic olive fibers have exhibited various enhancements in terms of mechanical performance. Both the tensile strength and modulus of elasticity have been dramatically improved at 20 wt.% fiber content. This was the most desired reinforcement condition among all considered cases. The olive fibers also possess the capability of maintaining relatively high ductility and impact strength properties, making them suitable for various industrial applications where high ductility is necessary. Thermal stability analysis using TGA and DTG has been employed to obtain accurate results.

Two sample sets of low density polyethylene (LDPE) were investigated and differentiated via comprehensive analysis of their microstructures with specific emphasis on branching. The sample sets were produced under well-defined conditions in a high-pressure mini-plant autoclave reactor and vary with respect to molecular weight and conversion. Focus was laid on analyzing the materials with respect to short- and long-chain branching by NMR, light scattering, viscosimetry and crystallization-based methods. Additionally, selected samples were fractionated preparatively. Temperature rising elution fractionation and solvent gradient fractionation were chosen to fractionate the materials according to crystallizability and molecular weight, respectively. Triple detector SEC provided molecular weight distributions, short chain branching densities, Mark–Houwink and conformation plots of the individual preparative fractions. It was proven that the fractionations were successful with regard to the desired properties and a deeper insight into the heterogeneous, complex microstructure of LDPE and its connection to process conditions was obtained.

Lignin was chemically modified with oligomeric polyethylene (oPE) to form oPE-grafted lignin (oPE-g-lignin) via lignin surface acylation and a radical coupling reaction with oPE. Then, pristine lignin and oPE-g-lignin were successfully compounded with low-density polyethylene (LDPE) through a typical compounding technique. Due to the oligomeric polyethylene chains grafted to the lignin’s surface, the interfacial adhesion between the lignin particles and the LDPE matrix was considerably better in the oPE-g-lignin/LDPE biocomposite than in the pristine-lignin/LDPE one. This demonstrated that oPE-g-lignin can serve as both a biodegradable reinforcing filler, which can be loaded with a higher lignin content at 50 wt-%, and a nucleating agent to increase the crystallization temperature and improve the tensile characteristics of its LDPE biocomposites. Moreover, the foamability of the lignin-reinforced LDPE biocomposites was studied in the presence of a chemical blowing agent (azodicarbonamide) with dicumyl peroxide; for an oPE-g-lignin content up to 20 wt-%, the cell size distribution was quite uniform, and the foam expansion ratios (17.69 ± 0.92) were similar to those of the neat LDPE foam (17.04 ± 0.44).

Nanocomposite polymer films are a very diverse research field due to their many applications. The search for low-cost, versatile methods, producing regulated properties of the final products, has thus become extremely relevant. We have previously reported a bulk-scale process, dispersing granulated metal oxide nanoparticles, of both unary and multi-component nature, in a low-density polyethylene (LDPE) polymer matrix, establishing a reference in the produced films’ optical properties, due to the high degree of homogeneity and preservation of the primary particle size allowed by this method. In this work, unmodified, free-standing particles, namely zinc oxide (ZnO), titanium dioxide (TiO2), aluminum oxide (Al2O3), and silicon dioxide (SiO2) are blended directly with LDPE, and the optical properties of the fabricated films are compared to those of films made using the granulation process. The direct blending process evidently allows for control of the secondary particle size and ensures a homogeneous dispersion of the particles, albeit to a lesser extent than the granulation process. Despite the secondary particle size being comparatively larger than its granulated counterpart, the process still provides a regulated degree of deagglomeration of the free-standing oxide particles, so it can be used as a low-cost alternative. The regulation of the secondary particle size tunes the transmission and reflection spectra, in both unary and mixed oxide compositions. Finally, the direct blending process exhibits a clear ability to tune the energy band gap in mixed oxides.

International audience; The rheological properties of a dispersion of cellulose nanocrystals (CNCs) in an aqueous solution of polyoxyethylene (PEO) have been investigated. A peculiar behavior is reported. Upon adding CNC, the viscosity of the suspension first decreases and then increases. Adsorption of PEO chains on the surface of the nanoparticles has been suspected. Freeze-drying of this PEO-adsorbed CNC dispersion was performed, and the ensuing lyophilizate was extruded with low density polyethylene. Compared to neat CNC-based nanocomposites, both improved dispersibility and thermal stability were observed. This simple and physical method constitutes an approach of choice for the melt processing of CNC-based nanocomposites with a hydrophobic polymeric matrix applicable at the industrial scale.

Mixtures of ultra-high-molecular-weight high-density polyethylene (UHMWPE), low-density polyethylene (LDPE), and polypropylene (PP) with various low-molecular-weight compounds were subjected to plastic deformation under a pressure of 1 GPa on an anvil-type high-pressure apparatus. The analysis of the mixtures was carried out by the DSC method and it was found that the thermograms of the deformed mixtures in the temperature range of 30- 100°C contain endothermic peaks of melting of small polymer crystals and exothermic peaks of cold crystallization. The enthalpies of melting of polymers in mixtures could be either higher or lower than the enthalpies of melting of the initial polymers. Exothermic peaks were present on the thermograms of mixtures with fluorescein at temperatures above the T m of polymers. Exo- and endothermic peaks below the T m of polymers, as well as exothermic peaks above the T m of polymers, were associated with the epitaxial growth of polymer crystals. The characteristics of thermal processes in deformed mixtures correlated with the amount of CH 3 groups in macromolecules.

The results of the study of the influence of the technological mode of injection molding on the pattern of changes in the physicomechanical properties of nanocomposites based on low density polyethylene filled with a thermosol of household waste are presented. As an object of study, nanocomposites containing 10 and 40 wt.% of thermosol are used.

The compositions of 10 different VCI compounds were optimized. Low density polyethylene (LDPE), ECA-5 copolymer (poly(ethylene-co-methyl acrylate) as an ethylene based coupling agent) and the prepa...

In this study low-density polyethylene (LDPE)/thermoplastic starch (TPS)/nanoclay (O-Mt) nanocomposites were prepared by a melt blending process using a Brabender mixer. Dicumyl peroxide (DCP) and nanoclay (O-Mt) were studied to improve interfacial adhesion and to obtain the various desired properties of the nanocomposites. The structure and properties of the materials were studied by X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and by tensile and Izod impact tests. X-ray diffraction analysis of the nanocomposites showed that the characteristic peaks of the clay were shifted to the lower angles, indicating an intercalated structure in the presence of dicumyl peroxide (DCP). The TGA curve indicated an improvement in the thermal stability of the materials with the amount of silicate and DCP. The mechanical properties of the materials were improved as a consequence of the increase in phase adhesion which gave an improvement in crystallinity confirmed by DSC. In addition, the impact strength of the modified materials was improved compared to the original materials. A modification of morphology as well as roughness was demonstrated by SEM and AFM.

This study aimed to prepare a bio-based organic adsorbent (W-PEI) with amine functionalization via Schiff’s reaction without carbonization of biomass. The bio-based organic adsorbent was prepared from wheat bran husk (WH), and amine functionalized to absorb CO2 gas by conjugating polyethyleneimine (PEI) via Schiff’s reaction to the aldehyde groups of periodated WH (p-WH). Then, the bio-based organic adsorbent was compounded with low-density polyethylene (LDPE) using a twin screw extruder. The polymeric composites (LDPE/W-PEI) and W-PEI were studied to characterize chemical structure, thermal properties, and CO2 adsorption ability. The CO2 adsorption capacity was measured by thermogravimetric analysis (TGA), and the analysis was performed through the exchange of N2 and CO2 under isothermal conditions at 75 °C. The amount of CO2 adsorption was 0.425 mmol/g of W-PEI powder, while that of polymeric composite (LDPE/W-PEI_20%) containing 20 wt% W-PEI was 0.034 mmol/g, which corresponds to an adsorption efficiency of 40% compared to that of the powder state. Therefore, polymeric composites with improved CO2 gas adsorption could be successfully applied to food packaging and building materials.

Metal–polymer–metal hybrid sandwich panels are gaining importance in civil, automotive and aerospace applications due to their light weight and damping properties. Compared with composite materials, hybrid materials consisting of separate metal and thermoplastic parts can be recycled much more easily. Besides their applications as covering material on buildings as well as general insulation material, recycled aluminum (Al)–low-density polyethylene (LDPE)–aluminum hybrid panels yield a potential usage of light ballistic protection. In this study, a standard hybrid panel of 3·2 mm polyethylene filling and two 0·4 mm aluminum metal sheets was experimentally tested under ballistic impact. A finite-element model was used with a commercial software program and validated against the experimental results. The finite-element results show that stacking of multiple layers of panels absorbs more energy than an equivalent single-layer panel. Six layers of stacked hybrid aluminum–LDPE–aluminum panels are capable of absorbing the impact energy of a 9 mm pistol projectile, and they can be utilized as recyclable inexpensive ballistic protection materials.

The use of nanotechnology-based, active antibacterial materials in food packaging is of great importance for users health. Related to such potential use nanocomposite films containing 2.5%, 5%, 7.5...

The article presents the results of a study of the rheological characteristics of dispersion-fi lled polymer composite materials (DFPCM) based on LDPE and glass balls of the ШСО-30 brand in a wide range of processing temperatures. For the fi rst time, the rheological properties of dispersion-fi lled polymer composite materials are considered from the standpoint of the formation of the dispersed phase with diff erent types of lattices, functional division of the polymer matrix (φp = Θ + В + М) and the construction of dispersed systems with diff erent types of structures (DS, LFS, MFS, HFS) in terms of generalized parameters (Θ, amid/d). This approach allows us to predict and describe the rheological properties for all DFPCMs with diff erent types of dispersed structures, using a dispersed phase (fi ller) with known geometric dimensions (d), packing density (parameter kpacking and φm) based on this polymer matrix. The infl uence of temperature on the processing technology of DFPCM with diff erent types of structures into products by injection molding has been established.

The improvements of the thermal, mechanical, morphological properties of low-density polyethylene (LDPE)/nanoclay (NC) composites were investigated. Low-density polyethylene (LDPE) with different NC contents 2 wt.% ( Vf= 8%), 4 wt.% ( Vf= 15), and 8 wt.% ( Vf= 27) with a fixed particle size (300μm) were prepared by the melt mixing process. The thermal tests (thermal gravimetric analysis) were performed to monitor the thermal stability of LDPE composites. The mechanical tests such as tensile strength, Young’s modulus, and strain at break were studied. The results of the thermal gravimetric analysis (TGA) display significant enhancement in thermal stability as the loading of NC increased in pure LDPE. The results showed that the NC fillers could effectively improve the mechanical properties of LDPE by comparison to pure LDPE, the tensile strength of LDPE/8 wt.% of NC are increasing by about 17% while Young’s modulus is increased by about 39%. From DMA results, the storage modulus is enhanced with increasing of NC loading into the LDPE matrix. The results of SEM photographs indicate that the incorporation 8 wt.% of NC displayed the best particles dispersion in the LDPE matrix.

The desired features of the green composite materials including the low cost, environmentally friendly and degradation characteristics have made them very suitable for wide industrial applications. However, wide extensive investigations about various agro waste fibers are still required to expand the utilization of such fibers into green materials to enhance the overall desired properties of green composites. Thus, in this work, investigations of the effects of fiber loading of olive fibers in the low density polyethylene (LDPE) green composites were carried out. The overall bio-composite flexural properties and rupture stress under impact environment were studied. All of the applied force, flexural strain, flexural strength, flexural moduli and maximum stress at fracture under impact environment of various designed composites were studied to determine the optimal reinforcing conditions of such green composites. Various composites with different fiber loading (20 wt%, 30 wt%, 40 wt%, and 50 wt%) were designed and fabricated to investigate the effect of fibers on the considered properties of the composites. Results have revealed the optimum reinforcing conditions to enhance the overall flexural property of the composites. The maximum flexural strength of the green bio-composites with various fiber loadings was found at the 40 wt% fiber content case with 34.6 MPa. It was also shown that both 30 wt% and 40 wt% fiber loading cases had the highest flexural moduli of more than 800 MPa. All of flexural strength, flexural modulus and impact rupture stress properties were dramatically enhanced with fiber loading up to 40 wt%, but decreased after that due to agglomeration of fibers. Moreover, olive fibers were capable of improving the flexural modulus of LDPE of more than 200%.

The oxidation and thermal stability of low-density polyethylene (LDPE) films (stabilized and unstabilized) used as greenhouse covering have been investigated. A mixture of kaolin, UV absorber, hindered amine light stabilizers (HALS) and heavy metals was used to stabilize LDPE films; these films were also compared with unstabilized LDPE films. Both films were exposed to natural weathering in Laghouat, Algeria. The oxidation resistance of unstabilized specimens for different ageing periods was determined by measuring the oxidation induction time (OIT) at 180 °C. It has been found that the highest OIT value was obtained for the unaged film and the values decline with ageing time. On the other hand, the stabilized specimens showed a significant stability under the conditions of OIT determination experiments. Furthermore, the oxidation resistance of these samples was evaluated by measuring the oxidation onset temperature (OOT). The results obtained showed that the OOT of the stabilized films ranges from 219 to 236 °C. Finally, a comparative analysis of the thermal stability results of both films was conducted. The activation energy of the photodegradation process of the both films was calculated by using TGA thermograms following the isoconversional approach. The results revealed that the stability of the stabilized specimens diminishes with ageing time and that the stabilizer additives improve the thermal stability of LDPE films. The influence of the photooxidation on the degree of crystallinity (based on DSC and WAXS techniques) of both films was also reported. Generally, there is a strong correlation between TGA, OIT, OOT, UV and FTIR results.

Red Balau saw dust was heat-treated at 180 °C and 200 °C for one hour and compounded with low-density polyethylene, LDPE, at 9, 20 and 37 wt%. The compounded materials were injection moulded into test specimens. Charpy impact assessment of the notched samples of the composites revealed that the peak load, P, and the critical stress intensity factor, Kc, increased with wood content and treatment temperature. While the energy to failure, W , and the critical strain energy release rate, Gc, decreased with wood content, the values were highest in composites made from wood flour treated at 180 °C and reduced in 200 °C treated wood composites. This behaviour revealed that heat treatment of wood flour at the 200 °C resulted in poorer impact properties of the composites. Dynamic mechanical analysis showed an increase in storage and loss modulus of composites made from untreated wood flour relative to the heat-treated ones. Tan delta values were also found to reduce in the heat-treated wood composites as a result of decreased damping. Heat treatment of wood flour at appropriate temperature enhanced both the mechanical and dynamic mechanical properties of the composites.

Polyethylene degrades slowly when discarded in the environment and exposed to natural weathering. A solution to this problem is the incorporation of additives to accelerate its biodegradation. In the present study, a biodegradable low-density polyethylene (LDPE) blend was obtained by the mixture of LDPE with a biodegrading additive (8% w/w) and the effect of accelerated weathering on biodegradation process was assessed. Chemical, mechanical, thermal, and morphological properties of non-aged and aged samples were studied. Results showed that aging process caused changes on structural characteristics (insertion of functional groups), morphological (appearance of micro-cracks and increased roughness), mechanical (greater stiffness and loss of plasticity) and thermal (lower degree of crystallinity and thermal stability) properties. The presence of biodegrading additive contributed to aging process, since polar functional groups were inserted into additive exposed to soil underwent greater degradation than their non-aged counterparts. CO2 production of aged LDPE blend demonstrated that accelerated weathering influences biodegradation process. In this work, due to availability of O2 gas, aerobic microorganisms can be the main responsible by the material deterioration, leading to production of microbial biomass, CO2 and H2O. Thus, the results of biodegradation (166 days) obtained in this work are promising, once it was reached a natural soil from South Brazil landfill.

The main properties and methods of producing LDPE are considered, the volumes of its production in the world and in theRussian Federationare given. The main characteristics of LDPE produced at PJSC Kazanorgsintez, ethylene-vinyl acetate copolymers, as well as methods for their production are represented. The measures taken to improve the properties of the end product are described.

The durability of HDPE and LDPE composites was studied using asphaltene as filler. Asphaltene is the polar macromolecules present in the crude oils. Examining the FTIR spectra of the composites revealed the lack of chemical bonds between asphaltene and HDPE/LDPE in the composite. Filler, asphaltene, is being a part of the physical mixture that does not make any covalent link with HDPE and LDPE polymers. The changes in the durability of the composites were monitored in samples exposed to UV irradiation for 480 h as well as natural outdoor weathering over a period of 6, 12, and 18 months. Superior light shielding by asphaltene filler leads to the stabilization of the composites. Alternatively, chemical effects may have also played a vital role in enhancing the weatherability of composites. In all composites studied, the natural and artificial weatherability compared to non-exposed HDPE and LDPE enhanced maximum load, tensile strength, and yield stress significantly due to the presence of asphaltene as a filler; however, percent elongation and modulus of elasticity decreased. Therefore, efficient reinforcement afforded by asphaltene is not accompanied by significant loss or enhancement in the durability of the composite.

This work sought to improve the properties of polypropylene (PP) for single layer film application by incorporating low density polyethylene (LDPE), poly(lactic acid) (PLA) and montmorillonite (MMT). The addition of LDPE in PP improved the elongation at break and tear strength. The PP/LDPE blend at a 80:20 (w/w) ratio was selected for blending with PLA and MMT and the PP/LDPE/PLA/MMT composite showed an increased tensile modulus, while the elongation at break decreased, with increasing PLA and MMT contents. The morphological structure of the respective nanocomposites was examined using X-ray diffraction, transmission electron microscopy and scanning electron microscopy analyses. For the barrier properties, the incorporation of PLA and MMT in PP/LDPE blend tended to dramatically decrease the oxygen permeability but slightly increase the water vapor permeability. Moreover, the PP/LDPE/PLA/MMT composite as a new effective film decreased the tomato loss weight during low temperature storage (15–20 °C) compared to the PP film.