Search

The mechanical strength of 2 film structures, machine-direction-oriented polyethylene (MDO-PE) laminated with linear low-density polyethylene (LLDPE) and polyamide (PA) laminated with LLDPE was evaluated. PA/LLDPE films demonstrated superior impact strength (0.834 J/mm²) compared to MDOPE/LLDPE films (0.445 J/mm²). Tensile strength for modified LLDPE (C6) was 40 N/mm², higher than standard LLDPE (C8) at 33 N/mm². The elongation at break for LLDPE reference C8 was 689 %, compared to 682 % for LLDPE sample C6. Film stiffness was measured at 162 MPa for the LLDPE reference C8 and 122 MPa for the LLDPE sample C6. PA films exhibited increased mechanical strength due to their intrinsic polyamide structure, while MDO-PE films benefited from molecular orientation during production. The modified LLDPE or C6 displayed improved impact resistance and tensile strength with reduced stiffness. MDO-PE/LLDPE films are promising for sustainable and robust food packaging. [ABSTRACT FROM AUTHOR]

This research work focuses on the development and analysis of copper-filled linear low-density polyethylene (LLDPE) coatings deposited on LLDPE substrate via a thermocompression process. A dry mechanical mixing technique is employed to mix the copper–LLDPE powders. This relevant technology aims to develop new solid lubricating layered composite coatings without a negative environmental impact. Four different materials of the coatings are considered, i.e., LLDPE + 2 wt.% Cu, LLDPE + 6 wt.% Cu, LLDPE + 10 wt.% Cu and LLDPE + 20 wt.% Cu. The microstructural characterizations indicate a good degree of dispersion and adhesion between the continuous and dispersed phases at 20 wt.% Cu coatings. The mechanical properties of the pure polymer and the fully filled composite materials are investigated experimentally using tensile tests and Micro-Vickers hardness. The stiffness, hardness and mechanical strength of the composites are enhanced. Friction tests are also carried out via a linear reciprocating sliding tribometer. The incorporation of copper powder has a significant improvement on the friction and wear properties of the developed coatings. Higher copper powder loading provides a lower friction coefficient and wear volume loss. The best tribological performances are obtained with the LLDPE + 20 wt.% Cu coating. The wear mechanism of the LLDPE substrate is severe adhesive wear, and it becomes mild abrasive wear in case of the 20 wt.% Cu coating. [ABSTRACT FROM AUTHOR]

Natural fiber‐reinforced composites are gaining significant popularity for their biodegradability and eco‐friendliness. Fiber modifications and hybridization have been used to address issues like hydrophilicity and fiber inhomogeneity. However, efficient manufacturing is still a challenge for natural fiber‐reinforced polymer composites. The present study explores the potential of microwave processing of hybrid laminates composed of sisal and jute fibers. The laminates, consisting of linear low‐density polyethylene (LLDPE) as matrix and sisal and jute as reinforcement materials were subjected to microwave processing at specific power, time, frequency, and loads. Four types of laminates with different stacking sequences: sisal‐sisal‐sisal (SSS), sisal‐jute‐sisal (SJS), jute‐sisal‐jute (JSJ), and jute‐jute‐jute (JJJ) were developed. The developed composites showed ~3% void content, with the SJS and JSJ composite having the least and highest void content, respectively. The SJS composite showed the highest tensile and flexural strength of 15.27 and 20.40 MPa, respectively, out of all the configurations and an improvement of 42% and 85% over pure LLDPE. Hybrid composites having high‐strength fibers in the skin layer exhibited superior mechanical properties. Microscopic examination of the fractured specimens revealed that fiber pull‐out and fiber breakage were the primary failure mechanisms of failure. Lateral failure due to delamination between matrix and fiber was predominant with grip and gauge regions as frequent failure points. The incorporation of sisal and jute fiber reinforcement into the polymers doesn't change the thermal stability of the fabricated composites significantly. The above results show that microwave‐assisted processing is a promising method for producing natural fiber‐reinforced hybrid polymer composites. Highlights: Development of hybrid laminates using microwave energy at 2.45 GHz.The mechanism of microwave‐based processing of polymer composites has been discussed.Effect of layering sequence on mechanical and thermal properties of the developed composite.Assessment of tensile strength with morphology, flexural strength and thermo‐gravimetric analysis. [ABSTRACT FROM AUTHOR]

The physical properties as well as thermal and electrical stability of copper particles can be improved by surface protection, which mainly depends on the coating material. Our study was, therefore, focused on the rheological, thermal, mechanical and electrical characterization of polymer composites by comparing uncoated (Cu), silver-coated (Cu@Ag) and silica-coated (Cu@Si) copper flakes in low-density polyethylene at various volume concentrations (up to 40%). Interactions among particles were investigated by rheological properties, as these indicate network formation (geometrical entanglement), which is important for mechanical reinforcement as well as establishing an electric pathway (electrical percolation). The results showed that geometrical and electrical percolation were the same for Cu and Cu@Si, ~15%, while, surprisingly, Cu@Ag exhibited much lower percolation, ~7.5%, indicating the fusion of the Ag coating material, which also decreased crystal growth (degree of crystallinity). Furthermore, the magnitude of the rheological and mechanical response remained the same for all investigated materials, indicating that the coating materials do not provide any load transfer capabilities. However, they profoundly affect electron transfer, in that, Cu@Ag exhibited superior conductivity (74.4 S/m) compared to Cu (1.7 × 10−4 S/m) and Cu@Si (1.5 × 10−10 S/m). The results obtained are important for the design of advanced polymer composites for various applications, particularly in electronics where enhanced electrical conductivity is desired. [ABSTRACT FROM AUTHOR]

Composites synthesized from natural waste and recycled plastic is quite a promising and interesting field for scientists and polymer industries. In the present study, bio-composites based on agriculture residue Sesamum indicum L. and recycled-low density polyethylene were synthesized by extrusion and injection molding technique at a fiber loading of 10–40 wt%. Additionally, 3% of maleic anhydride grafted low density polyethylene was used as a compatibilizer. The prepared composites were irradiated at 25 kGy, 75 kGy and 125 kGy doses of gamma rays. The effects of different fiber content and gamma doses on mechanical properties were studied statistically by Design Expert software. Response surface methodology was employed to depict the interaction among various factors and optimization was done by desirability index method. Findings indicated that composites having 30% Sesamum indicum L. irradiated at 125 kGy demonstrated best mechanical properties. A significant enhancement in tensile and flexural properties of irradiated composites can be explained effectively in terms of the cross-linking effect. The fiber–matrix adhesion and modifications in composite structure was characterized by fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and X-Ray diffraction (XRD) analysis. Furthermore, thermal stability of the composites was also found to be increased. In addition, gamma-irradiated composite exhibited the highest storage modulus and a decrease in mechanical loss factor was also observed. [ABSTRACT FROM AUTHOR]

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

In the present work, we report the effect of low‐temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low‐density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties. It was observed that the tensile strength decreased with the increased loading content of CFSP, and 1% CFSP/LLDPE exhibited the highest tensile strength. To study the effect of low‐temperature plasma treatment, 1% CFSP/LLDP polymer composite with high tensile strength was plasma treated with O2 and SF6 gas before blow film extrusion. The 1% CFSP/LLDPE/SF6‐extruded blown films showed increased thermal decomposition, crystallinity, tensile strength, and modulus. This may be due to the effect of crosslinking by the plasma treatment. The maximum thermal decomposition rate, crystallinity %, tensile strength, and modulus obtained for 1% CFSP/LLDPE/SF6 film were 500.02°C, 35.79, 6.32 MPa, and 0.023 GPa, respectively. Furthermore, the biodegradability study on CFSP/LLDPE films buried in natural soil for 90 days was analyzed using x‐ray fluorescence. The study showed an increase in phosphorus and calcium mass percent in the soil. This is due to the decomposition of the hydroxyapatite present in the CFSP/LLDPE biocomposite. [ABSTRACT FROM AUTHOR]

This study focuses on the development of a functional yoghurt oral film strip with antibacterial properties and probiotics [(Streptococcus thermophilus (S. thermophilus), Lactobacillus bulgaricus (L. bulgaricus), and Lactococcus cremoris (L. cremoris)] using a pectin/glycerol mixture. The tensile characters, colour, physiochemical characters, in vitro disintegration time, mouth dissolving time and in vitro dissolution test of the functional yoghurt oral strip was compared with commercial oral strips. The study examined the storage stability of functional yogurt oral strips over a period of 35 days at room temperature (25 °C) using blister packs made of polypropylene/aluminium and polypropylene/linear low-density polyethylene (LLDPE). Significant changes in mechanical properties, colour, surface pH, in vitro disintegration, and mouth dissolving time was observed with in vitro dissolution time of 6 min. Functional oral strip showed significant (p < 0.05) reduction in surface pH and probiotic viability, along with a significant increase in mouth dissolving time during storage in both packaging materials. Developed functional yoghurt oral strip also demonstrated better antibacterial quality on both storage materials with similar in vitro dissolution time periods. A satisfactory probiotic viability (> 6 log CFU/strip) was upheld for 28 days in a polypropylene/aluminium blister pack, resulting in an extended shelf life for the functional yogurt oral strip. Therefore, this functional yoghurt oral strip development can be considered as a promising production method to retain functional qualities with longer shelf life at room temperature. [ABSTRACT FROM AUTHOR]

Nowadays, increased food safety and decreased food waste are two of the major global interests. Self-healable active packaging materials are an attractive option to achieve such targets. This property is critical for the hygiene and the consumption appropriateness of the food. Polylactic acid is a very promising polymeric matrix that potentially could replace the widely used low-density polyethylene due to its biobased origin and its easy biodegradable nature. The main drawback of this polymeric matrix is its brittle, fragile nature. On the other hand, tetraethyl citrate is a biobased approved food additive which became an attractive option as a plasticizer for industries seeking alternative materials to replace the traditional petrochemically derived compounds. A novel biobased film exhibiting self-healing behavior suitable for food-active packaging was developed during this study. Polylactic acid's brittleness was reduced drastically by incorporating tetraethyl citrate, and a random cut on the original self-repairing film was fully healed after 120 s. The optimum concentration of tetraethyl citrate in the polylactic acid was around 15% v/w with a water/oxygen barrier close to the relevant of polylactic acid and low migration. According to the EC50 parameter, the antioxidant activity was 300% higher than the relevant of pure polylactic acid, while according to the thiobarbituric acid and heme iron parameters, the film resisted lipid oxidation and deterioration. Finally, the total viable count parameter indicates the strong antimicrobial activity of this sample. [ABSTRACT FROM AUTHOR]

Low‐density polyethylene grafted glycidyl methacrylate (PE‐GMA) and low‐density polyethylene maleic anhydride (PE‐MAH) are low‐cost commercialized polymeric materials. Because of their low viscosity, molecular flexibility, solubility parameters, and polarity similar to asphalt or epoxy resins, PE‐GMA and PE‐MAH are added to epoxy asphalt (EA) to improve the compatibility and toughness of EA. The microstructure, viscosity, thermal stability, dynamic mechanical behavior, and mechanical properties of PE‐GMA and PE‐MAH modified EA were investigated. Smaller and more uniformly distributed asphalt particles were formed in mixes with lower PE‐GMA or PE‐MAH content. The polymer dispersity index of the modified EA is 1.1–1.4 lower than that of the pure EA, and compatibility is significantly improved. The reason is that PE‐GMA and PE‐MAH are polyethylene with polar functional groups, and their molecular structure includes both polar functional groups and nonpolar polyethylene chains, improving the compatibility between polar epoxy resin and nonpolar asphalt in EA. In addition, the incorporation of PE‐GMA or PE‐MAH effectively improves the low‐temperature toughness of EA. It also has high damping performance and tan δ, improved the durability and comfort of EA pavement. [ABSTRACT FROM AUTHOR]

Linear low-density polyethylene (LLDPE) is a type of plastic with a high percentage of solid waste and is hardly degradable. The characteristics of LLDPE such as high toughness and low density have the potential to be an alternative aggregate substitute for applications in non-structural mortar composites. The purpose of this study was to determine the suitable formulation of LLDPE aggregate substitution against silica sand for the application of non-structural adhesive mortar composites. Vinyl acetate/ethylene (VAE) surfactant (1.2 wt%) was used to improve the interface between LLDPE and the cement matrix. Mechanical testing; XRD and FTIR characterization; density measurements; compression, adhesion, and thermogravimetric test; and morphological observation were carried out in this experiment. The results showed that LLDPE substitution decreased physical properties and accelerated thermal degradation. Cracks occurred on higher amount of LLDPE composition due to big difference in polarity. Suitable LLDPE substitution composition for adhesive mortar is up to 50%. [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]

Due to its versatile properties polyvinyl chloride (PVC) based materials are employed in several applications. At high temperatures and in acidic media PVC is prone to release toxic materials into the environment. Several reports are available in the literature about the modification of PVC to minimize such problems. Herein, an attempt is made to prepare PVC/Halloysite nanotube (HNT) nanocomposites with a fixed amount of compatibilizer, OPTIM GE 344 (maleic anhydride modified very low-density polyethylene (VLDPE)) and characterize the composites with respect to thermal stability, mechanical properties, and structural aspects. Both tensile and flexural strength showed appreciable improvement for the 4 wt% loading of the nanofiller. Thermogravimetric analysis (TGA) showed that the maximum degradation temperature improved by approximately 24 °C for 4 wt% filled composites. PVC thermomat measurements of the samples were used to study the thermal stability of the composites. PVC without HNT showed 36 min as the stability time and it increased to 398 min for 4 wt% of HNT loading. To complement the thermal properties of the composites, the mass loss measurement and contact angle behavior of the composite surfaces were also done. The decrease in contact angle values denoted better surface wettability properties. The mass loss measurements showed a decrease with respect to the filler loading of HNT, indicating a better interaction between the polymer matrix and HNT. [ABSTRACT FROM AUTHOR]

Due to the intensive search for new types of advanced polymer materials for targeted applications, this work offers insight into the properties of low-density polyethylene/hematite composites. The specific feature of this study lies in the use of elongated hematite particles of different shapes. Uniform ellipsoid-, peanut- and rod-shaped hematite particles were hydrothermally synthesized and incorporated into the polymer matrix of low-density polyethylene (LDPE). LDPE/hematite composites are prepared by melt mixing. Hematite particles are characterized by scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). The pure LDPE polymer and LDPE/hematite composites were studied by FT-IR and UV-Vis-NIR spectroscopy and by thermogravimetric analysis (TGA). The determination of the mechanical and barrier properties was also carried out. The obtained results indicate the influence of the elongated particles on the improvement of LDPE properties. An increase in thermal stability and UV-absorption was observed as well as the improvement of mechanical and barrier properties. The improvement of the composites' properties in comparison to the pure LDPE is especially visible in the composites prepared with low content of hematite (0.25%). LDPE/hematite composites have promising characteristics for application as packaging materials with enhanced mechanical, thermal and barrier properties as well as UV-protective materials. [ABSTRACT FROM AUTHOR]

Linear low‐density polyethylene (PE) containing an inclusion complex composed of β‐cyclodextrin and d‐limonene (CD‐lim) is proposed as an innovative food wrapping material with antimicrobial features. PE/CD‐lim composites are prepared by conventional, high‐volume processing, and the optical and mechanical properties of the developed formulations appear suitable for their use as food packaging materials. Compared to plain PE, the PE/CD‐lim films have improved haze and UV–vis outcomes, but also decreased gloss values. Addition of CD‐lim slightly increases water uptake, up to levels suitable for the foreseen application. It also allows to improve performance of PE as food packaging material, since the PE/CD‐lim composites provide barrier to ultraviolet light, an added value for packaging of fatty acids‐containing food items, whose shelf life is often limited by oxidation caused by UV light. Most importantly, PE/CD‐lim composites exhibit significant antimicrobial properties against a wide range of microorganisms, including fungi and bacteria. Hence, PE films containing CD‐lim display suitable properties to play a role as active food packaging films. Highlights: Development of polyethylene‐based composites containing a natural fillerComposite films with enhanced antimicrobial and antifungal efficiencyImproved transparency to visible light and barrier to UV of the composites [ABSTRACT FROM AUTHOR]

Three different compatibilizers were used; namely: Fusabond (FSB) which is a maleic anhydride grafted polyethylene, montanic acid (E wax), and used engine oil (UEO) were incorporated into cellulose acetate/low density polyethylene (CA/LDPE) composites at three fiber contents: 5, 15 and 30 phr. Three series of samples consisting of treated composites using coupling agents were prepared, while one group was left untreated as a reference composite. To assess the performance of the composites, different testing techniques were used. These include attenuated total reflectance spectroscopy(FTIR-ATR), thermogravimetric analysis(TGA), differential scanning calorimetry(DSC), tensile test, dynamic mechanical thermal analysis(DMTA), and scanning electron microscopy(SEM). The presence of ethylene vinyl acetate (EVA) in LDPE enhanced the adhesion at the polymer/fiber interface, as reflected by the increase of Young's modulus by 75, 166, and 245% respectively compared to neat LDPE, an increase of the storage modulus and a reduction of the damping factor value. Incorporating Fusabond was also found to affect slightly the mechanical properties with high fiber contents compared to the composites without the coupling agent by 13%. On the other hand, the use of montanic acid and used engine oil affected the cellulose acetate fibers distribution within the matrix. The UEO enhanced the dispersion but acted as a plasticizer resulting in a slight reduction of the crystallinity. Moreover, the interaction between the LDPE matrix and the CA fibres was indicated by the resulting fracture surface morphology. The results obtained suggest that the CA/LDPE composites would be suitable for packaging or used in automotive applications. [ABSTRACT FROM AUTHOR]

Linear low‐density polyethylene (LLDPE) and different concentrations (5‐20 wt%) of magnesium hydroxide (MAH) as a filler either with or without the addition of graphene nanoplatelets (GNPs) were peroxide cross‐linked using dicumyl peroxide as a cross‐linking agent in a twin‐screw extruder. The mechanical, thermal stability, flame retardancy, morphological, and rheological properties of the prepared samples were investigated. The mechanical properties of the peroxide cross‐linked LLDPE samples with higher MAH and GNP in the matrix were significantly improvement compared to neat LLDPE. This indicates that the addition of MAH and GNP to the peroxide cross‐linked LLDPE matrix could be suitable reinforcing fillers to achieve better and enhanced mechanical properties, particularly tensile strength. Conversely, a significant decrease in the elongation at break values was found for peroxide cross‐linked LLDPE samples compared to neat LLDPE. Similarly, results of thermogravimetric analysis revealed remarkable thermal stability enhancement in the peroxide cross‐linked LLDPE samples with higher MAH and GNP compared to neat LLDPE. The results from UL94 test demonstrated that the peroxide cross‐linked LLDPE samples comprising higher MAH with GNP exhibited improved V = 0 rating compared to poor no rating (NR) for neat LLDPE. Furthermore, the scanning electron microscope and digital images shown improved flame retardancy properties for these samples because of the formation of protective char layer on the sample surface. The complex viscosity for the peroxide cross‐linked LLDPE samples, at lower frequency, increased with increasing MAH loading and further addition of GNP compared to neat LLDPE. Highlights: Cross‐linked polyethylene with flame retardant (FR) and nanofiller were prepared.Effects of cross‐linking and FR on the final properties of the polymer were studied.20wt% FR with 3 phr nanofiller promoted the final properties of the polymer.Higher filler loading in the polymer improved flame retardancy and thermal stability.Combined effect of cross‐linking and FR has shown major improvement. [ABSTRACT FROM AUTHOR]

Featured Application: This work is of particular interest in the design of products widely used in daily life, such as HDPE and LLDPE blend plastic bags. The aim of this study is to analyze how the main process parameters (BUR, TUR, and TR) affect the mechanical properties of this type of product, helping designers to adapt the production to customers' new requirements while maintaining the product properties. All the samples were manufactured on an industrial scale. The results are beneficial so that the highest tensile and impact properties can be obtained through minimal changes in the already mentioned process parameters, thus also reducing the amount of waste due to products manufactured outside the specification limits. Polyethylene plastic bags manufactured via blown film extrusion have different quality specifications depending on their intended use. It is known that the mechanical properties of a film depend on the process parameters established, but little is known concerning how they affect one another, even more so due to the variety of polyethylene materials and processing techniques. This study focuses on establishing a proper correspondence of important mechanical properties like the dart impact, tensile strength at break, and elongation at break with commonly used process parameters like the blow-up ratio, take-up ratio, thickness reduction, and neck height, for a high-density polyethylene hexene copolymer and a linear low-density polyethylene butene copolymer blend film. Because this polyethylene mixture is an anisotropic material, interesting R2 values equal to or higher than 0.90 were found: a BUR with elongation at break and tensile strength at break in the MD and TD, a TUR with elongation at break in the MD and tensile strength at break in the MD and TD, and a TR with elongation at break and tensile strength at break in the MD. Also, a relationship between the dart impact and both the neck height and thickness were found. [ABSTRACT FROM AUTHOR]

This research work was carried out with the aim of obtaining the optimum combination of the novel linear low-density polyethylene/ethylene vinyl acetate (LLDPE/EVA)nanocomposites by incorporation reduced graphene oxide (rGO) as reinforcement andLLDPE-g-MA as compatibilizerwith the new solution method.Different samples were synthesized by various amounts of rGO from 0.1 phr to 1 phr, 80 phr LLDPE, 5 phrLLDPE-g-MA, and 20 phr EVA.Thermal, rheological, mechanical, and morphological properties were investigated. Results showed that the modulus, elongation-at-break, and tensile strength increased significantly with the increase of rGO content in the presence of LLDPE-g-MA. Transmission electron microscopy (TEM) images showed that LLDPE-g-MA can cause a better dispersion of rGO in the polymeric matrix by creating an interface between LLDPE, LLDPE-g-MA, and EVA. In addition, the field emission scanning electron microscopy (FESEM) images showed that with the increase in the amount of rGO, the particlediameter of the EVA dispersed phase decreased significantly, which is the result of the interactions between the carbonic nanofiller and the LLDPE-g-MA compatibilizer. [ABSTRACT FROM AUTHOR]

Maleic anhydride-modified homopolymerized polypropylene (PP-g-MAH) and maleic anhydride-modified polyolefin elastomer (POE-g-MAH) were used as bulking agents to improve the poor processing and mechanical properties of highly filled composites due to high filler content. In this study, a series of linear low-density polyethylene (LLDPE)/magnesium hydroxide (MH) composites were prepared by the melt blending method, and the effects of the compatibilizer on the mechanical properties, flame retardancy, and rheological behavior of the composites were investigated. The addition of the compatibilizer decreased the limiting oxygen index (LOI) values of the composites, but they were all greater than 30.00%, which belonged to the flame retardant grade. Mechanical property tests showed that the addition of the compatibilizer significantly increased the tensile and impact strengths of the LLDPE/60MH (MH addition of 60 wt%) composites. Specifically, the addition of 5 wt% POE-g-MAH increased 154.07% and 415.47% compared to the LLDPE/60MH composites, respectively. The rotational rheology test showed that the addition of the compatibilizer could effectively improve the processing flow properties of the composites. However, due to the hydrocarbon structure of the compatibilizer, its flame retardant properties were adversely affected. This study provides a strategy that can improve the processing and mechanical properties of highly filled composites. [ABSTRACT FROM AUTHOR]

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

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

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

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

A new polymer based on nanocomposites was prepared to examine its radiation-shielding properties for potential industrial applications. Bismuth oxide (Bi 2 O 3) nanoparticles and flower tungsten oxide nanostructures (FL-WO 3) was hydrothermal synthesized. The Bi 2 O 3 nanoparticles and WO 3 nanostructure formation were confirmed using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy (TEM). The Bi 2 O 3 nanospheres had an average diameter of approximately 30–68 nm. The WO 3 nanostructure and Bi 2 O 3 nanoparticles were incorporated into low density polyethylene (LDPE) to fabricate a nanocomposite. The radiation-shielding performance of different nanocomposites was investigated. The results showed that LDPE loaded with WO 3 , WO 3 /Bi 2 O 3 , and Bi 2 O 3 displayed higher tensile strength and thermal stability than unloaded LDPE. The results showed that the LDPE loaded with 3% Bi 2 O 3 performed better gamma attenuation at 662, 1173, and 1332 keV. Additionally, WO 3 , WO 3 /Bi 2 O 3 , and Bi 2 O 3 as ecofriendly additive-reinforced LDPE materials have a gamma-ray-shielding performance. The results indicate that LDPE containing Bi 2 O 3 have higher gamma-ray-shielding properties than other nanocomposites. [Display omitted] • Synthesis of bismuth oxide (Bi 2 O 3) nanoparticles and flower WO 3 nanostructures (FL-WO 3) by hydrothermal simple method. • Fabrication and characterization of new polyethylene nanocomposites containing Bi 2 O 3 and WO 3 as an eco-friendly additive. • Usage of LDPE/WO 3 /Bi 2 O 3 composite that should be utilized the gamma radiation shielding. [ABSTRACT FROM AUTHOR]

Polymers used in food packaging should have unique properties, including anti-bacterial properties, good mechanical properties and permeability to air and water. To achieve these properties, some nanomaterials are incorporated into the polymeric matrix to be suitable for such a precise application. Thus, polymer nanocomposites emerged as one of the most important recent trends in the packaging materials industry. Here, titanium dioxide nanoparticles (TiO2-NPs) were synthesized by the sol–gel method and incorporated into pure low-density polyethylene (P-LDPE) at different concentrations (0, 2, 4, 8 wt %.). The prepared nanocomposites were characterized via a scanning electron microscope (SEM), X-ray diffraction (XRD), and thermogravimetric analysis. The size of TiO2-NPs is ranged from 13 to 47 nm. The crystallinity index of LDPE increased by the addition of TiO2-NPs from 0.32 to 0.55. Also, the thermal stability of LDPE improved by 67 °C. Studies of the mechanical properties, antibacterial activity and permeability measurements of nanocomposites films have demonstrated their potential for use in perishable food packaging. The results showed an increase in oxygen permeability from 55.25 cc/M2 day for P-LDPE to 72.84 cc/M2 day for LDPE-loaded with 8% TiO2. On the contrary, the impeded TiO2-NPs inside LDPE films reduced the water vapor transmission from 2.22 g/(m2 day) to 0.92 g/(m2 day). The tensile strength of P-LDPE increased from 16.7 MPa to 28.95 MPa for nanocomposite loaded with 8% TiO2. The ability of TiO2-NPs O2 to generate the potentially reactive radical species induced the antibacterial activity of LDPE to Gram-negative and Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

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

Clay-reinforced polymer composites have been considered as highly demand nanocomposites since several decades. To be utilized as packaging materials, these nanocomposites should possess good impermeability to oxygen and water vapor. The major compatibility issue of the hydrophilic inorganic nanofillers with hydrophobic thermoplastics has been overcome in this work by using the 'grafting to' silylation method of two different nanoclays, namely montmorillonite Na+ and halloysite (HNT) nanoclays, at 85 ℃. Organosilanes: 3-aminopropyltriethoxysilane (3-APTES) and vinyltrimethoxysilane (VTMS) were used to functionalize these nanoclays to improve interfacial bonding with linear low-density polyethylene (LLDPE) polymer chains. TGA analysis resulted in higher amount of grafting yield percentages for silane-treated MMT nanoclays (28.9% for MMT-APTES and 24.3% for MMT-VTMS) which are much higher than silane-functionalized HNT nanoclays. The amount of 1, 3 and 5 wt% of each organoclay was melt and mixed with LLDPE to enhance the overall performance properties of the resultant nanocomposites. The maximum tensile strength exhibited by the nanocomposite is around 20.6 MPa for 3 wt% of MMT-APTES concentration. Also, Young modulus improves up to 56% compared to neat LLDPE on the addition of 5 wt% of silane-treated organoclay. The microscopic analysis, especially TEM, provided information about the better dispersion of anisotropic fillers inside the thermoplastic matrix. Moreover, such filler compatibilization also showed 29.4% reduction in oxygen transmission rate (OTR) and 63.5% reduction in water vapor transmission rate (WVTR) value of composite materials with only 5 wt% of nanoclay loading along with improved rheological and ultraviolet (UV) barrier properties of these nanocomposites. The prepared nanocomposites with improved barrier properties could be ideal alternatives for flexible thermoplastic composites as packaging materials. Silane functionalization of nanoclays led to uniform distribution of clay in LLDPE matrix which improved mechanical and barrier properties of nanocomposites. [ABSTRACT FROM AUTHOR]

The current study reviews the viability of various fibre-polymer composites and treatment techniques along with the intricacy involved in improving the rotational moulding process. It is a method used in the manufacturing of hollow plastic items free from stress. As the rotational moulding process has gained prominence in a variety of crucial applications in recent years, a detailed analysis of this technique is important. For this reason, an exhaustive review of various fibres and polymers used in rotational moulding along with different pre-treatment techniques for improving the processability has been carried out and categorised into three sections. The first section deals with the type of polymers which are used for the process along with their nature and suitability for rotational moulding. The second section deals with the study of different fibres that have been blended with the polymers. The last section of the review discusses the different fibre treatment techniques which can be used to improve polymer-fibre compatibility. From a wide range of polymers used, it has been observed that the ease of processability of linear low-density polyethylene makes it the most suitable grade for rotational moulding. It can also be noticed that artificial fibres provide good mechanical properties compared to natural fibres but being eco-friendly and having low cost, natural fibres are more vital in the application. It is evident from the review that fibre pre-treatment enhances the polymer-fibre compatibility which improves the mechanical properties of the rotationally moulded products. Further, it can be concluded from the literature review that an adequate variety of polymer and fibre along with fibre treatment techniques can make an important contribution to the rotational moulding process. [ABSTRACT FROM AUTHOR]

With the development of degradation technologies such as chemical‐catalysis and bio‐catalysis, starch‐polyethylene (PE) composites have been revitalized as industrial packaging materials. However, starch and PE suffer from interfacial incompatibility. In this study, poly(octene ethylene) grafted glycidyl methacrylate (POE‐g‐GMA) was added at relatively low amounts (0–7 wt%) to construct robust structures between thermoplastic starch (TPS) and low‐density polyethylene (LDPE). Tensile strength increased by 36.39% with the addition of 1 wt% POE‐g‐GMA. Meanwhile, a smooth surface was observed by SEM, and a fibrillar cross‐linked structure appeared on the fractural surface of the blend. POE‐g‐GMA formed a stable "bridge" at the interface between TPS and LDPE, which increased the thermal stability of the blend as well. The crystallinity of LDPE increased from 20.5% (without addition) to 32.8% (with 1 wt% addition), whereas the average crystallite size decreased slightly. The optimal POE‐g‐GMA content was found to be 1 wt% based on mechanical and thermal measurements. The results of this study can provide a reference for improving the interfacial compatibility of biopolymers and fossil‐fuel‐based polymers. [ABSTRACT FROM AUTHOR]

Utilizing oxo-degradable additives is an alternate, efficient method of managing plastic trash. To prepare the polymer chain for microorganisms to break down the fragments over time, oxo-degradation of plastics involves breaking the chain into small pieces. In this study, a film with a thickness of 35 µm is created by mixing a mixture of linear low-density polyethylene (LLDPE) and d2w grade master batch (pro-oxidant). This thickness falls within the range of specifications for linear low-density polyethylene (LLDPE) films manufactured in petrochemical businesses. Additionally, is the study investigates how the mechanical characteristics of linear low-density polyethylene (LLDPE) are affected by the addition of a d2w pro-oxidant additive at five different weight percentages (0, 0.5, 1, 2, and 3% w/w). After thermal processing for films in an oven for one to seven days, the progress of LLDPE film is monitored by FTIR analysis to check for the presence of the carbonyl group by assessing the mechanical properties of the film. Tensile strength at break, tensile strength at yield, elongation at break, and elongation at yield are the mechanical qualities that are measured. Both the machine direction (MD) and the transverse direction (TD) are used to measure all properties. Following seven days of exposure to the oven at 70 °C, the mechanical properties of the film deteriorated. Both in the machine and transverse directions (MD and TD), the tensile strength at break dropped by 46.62% and 31.8%, respectively. Both in the machine and transverse directions (MD and TD), the tensile strength at yield dropped by 22% and 36.36%, respectively. Both machine and transverse elongation at break (MD and TD) were reduced by 21% and 38.36%, respectively. Following the addition of pro-oxidant and after thermo-oxidative treatment in an oven at 70 °C for 7 days, the results of the FTIR measurement for LLDPE did not significantly alter. [ABSTRACT FROM AUTHOR]

The environmentally friendly natural fiber reinforced polymers are increasingly taking attention in several industries like automotive and construction due to their properties such as being synthesized in desired properties, easy processing, non-corrosion, low weight, and low cost. In this study, untreated/alkali-treated/silane (1.5%)-treated/alkali+ silane treated jute fabrics (25%) were reinforced to low density polyethylene (LDPE) polymer (75%) with 1%, 3%, 5% and 7% maleic anhydride additives for composite production by using hot pressing method. Further, the effect of jute fabric surface treatments on the tensile strength, flexural strength, and impact resistance properties of the LDPE/jute composites were investigated with the absence/presence of maleic anhydride additives. The results indicate that the alkali/silane treatment of jute fibers led to more than 30% improvement in mechanical properties of the composite structures when reinforced to untreated LDPE, and the mechanical properties of the composites had more than 45% improvement by maleic anhydride addition to the polymer in ideal ratios with untreated jute reinforcement.

Ceramifiable polymer composite is an excellent method for enhancing the flame retardancy of the materials. In case of fire, ceramifiable polymer composites are converted into a ceramic barrier that can impede heat transfer, segregate combustible material from oxygen and prevent the polymer matrix from pyrolysis. The ceramic fillers added to the composites play a key role in the ceramic forming process of the composites. Here, the effects of three types of Si-based mineral fillers on the ceramifiable and mechanical properties of polyethylene composites were investigated. Wollastonite (CaSiO 3), silica powder (SiO 2), or pyrophyllite (Al 2 Si 4 O 10 (OH) 2) was incorporated into low-density polyethylene with glass powder to prepare the composite materials. The composites were subjected to sintering at various temperatures (600, 800, and 1000 °C). The ceramic residues formed were characterized by flexural strength, apparent porosity, linear shrinkage, and thermogravimetric measurements. All these three fillers greatly enhanced the ceramifiable properties of the polyethylene composites and the mechanical properties of the ceramic residues. X-ray diffraction analysis and scanning electron microscopy reveal that the filler molecules were firmly connected by the molten glass while the pores in the ceramic residues were released at elevated temperatures, leading to a dense ceramic structure with excellent mechanical properties. [ABSTRACT FROM AUTHOR]

In this study, some of the critical fundamental properties, which are holding importance in usage areas, of low-density polyethylene (LDPE) film were studied by embedding size-graded and polydopamine-coated halloysite nanotubes into the polymer matrix. This concept evaluated the importance of the well-dispersion of nanoparticles in the composite system and interfacial adhesion between nanofiller and polymer matrix on the degree of crystallinity and mechanical properties. For this purpose, halloysite nanotubes, coated with polydopamine and size graded afterward, were integrated into the LDPE matrix by the twin-screw extrusion process, following which, nanocomposite films were prepared by film-blown technique. Both effects of halloysite nanoparticles, having the polydopamine layer on their surface and size-graded, on properties such as mechanical strength, thermal feature, and degree of crystallinity, of those directly acting on the usage goals of LDPE-based films, were tested. [ABSTRACT FROM AUTHOR]

The recycled polyolefin waste which included polypropylene (PP) and low‐density polyethylene (LDPE) were collected from hospital and subsequently sterilized by 1% sodium hypochlorite and followed by microwave disinfection. The sterilized BMW were analyzed for growth of pathogens if any. FTIR analysis was performed to analyze the composition of the waste as well as Carbonyl index to evaluate the extent of degradation post sterilization process. Recycled blends were prepared using melt extrusion technique and ethylene diene monomer was added to balance the interface between the varied polyolefin waste. Blends were studied for mechanical and morphological properties. Thermal analysis employed DSC revealed two different peaks of crystallization and melting revealing incompatibility in the blends. DMA showed reduction in the modulus with incorporation of LDPE and EPDM. SEM analysis confirmed the homogeneous distribution of RLD droplets with reduction in the interparticle distance indicates the partial miscibility. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Because of their high filler loadings, commercial-grade clean flame-retardant materials have unstable mechanical properties. To address this issue, intumescent polymers can be used to develop clean flame retardants with very low levels of smoke and toxicity generation. An intumescent flame retardant (IFR) system composed of red phosphorus (RP), zinc borate (ZB), and a terpolymer of ethylene, butyl acrylate, and maleic anhydride (EBM) was used to prepare EVA (ethylene-vinyl acetate) and EVA/LLDPE (linear low-density polyethylene) composites; their mechanical and flammability properties were systematically investigated. The limiting oxygen index (LOI) of the EVA/LLDPE (as base material) composite containing RP and ZB mixed with nonhalogenated flame retardant, mainly magnesium hydroxide (MH) and coadditives, including processing aids and thermal stabilizers, was established. RP was found to have little effect on the tensile properties of EVA/LLDPE 118W/120 phr flame-retardant (MH + RP) composites. There was a minute difference in the effective trend of RP between tensile strength and elongation at break. Following the addition of ZB, the elongation at break of the composites gradually decreased with increasing RP content and then leveled off when the RP content was over 10 phr. Mechanical properties (elongation at break and tensile strength) can be best maintained at below 10 phr content of RP. The mechanical properties decreased with lower amounts of EBM content. In addition, flame retardancy increased when the EBM content decreased. The findings further revealed that MH and RP have poor compatibility, yielding poor mechanical properties. The LOI greatly increased with RP content, even though the total content of flame retardants (main + intumescent flame retardant) was the same in all formulations. Only over 5 phr RP content formulations passed V-0 of the UL-94 test. When under 5 phr, the RP content formulations did not pass V-0 of the UL-94 test. [ABSTRACT FROM AUTHOR]

In this paper, two Zigler‐Natta catalysts (ZNCs) were used to synthesize a commercially available linear low‐density polyethylene (LLDPE), widely used in the packaging industry, on an industrial scale. The catalysts differ only in their ability to distribute comonomers between short and long chains. Both catalysts were fully characterized in the first section, and two similar ethylene/1‐butene copolymers were made using them. Afterward, the produced copolymers were fully characterized using different techniques; namely, differential scanning calorimetry (DSC), successive self‐nucleation and annealing (SSA), oxygen induction time (OIT), melt flow index (MFI), rheometric mechanical spectroscopy (RMS), and a wide range of mechanical experiments. It was revealed that while the presence of comonomers in short chains can reduce their resistance against oxidation (by more than 30%) and can cause a dramatic change in friction coefficients (by more than 20%), some of the other main mechanical properties of the made copolymers were independent of comonomer distribution between long and short chains. In addition, it was shown that ethylenic copolymers' strain hardening modulus (SHM) takes advantage of the homogenous distribution. [ABSTRACT FROM AUTHOR]

There is an increasing need to develop new polymer composites with improved properties compared to conventional pure polymer materials. This work aims to develop composites of low-density polyethylene (LDPE) and iron oxide hematite particles. For this purpose, different types of hematite particles with well-defined shapes and narrow size distributions were synthesized: HC2 sample with pseudocubic hematite particles of an average diameter of 1020 nm, HE1 sample with ellipsoidal hematite particles of an average diameter of 533 nm, and HS1 sample with spherical hematite particles of an average diameter of 168 nm. The mass fractions of hematite in the composites were 0.25%, 0.5%, and 1%. Prepared LDPE/hematite composites were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and diffuse reflectance ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy. The mechanical and barrier properties were also studied. The obtained results showed that all prepared composites have improved properties compared to the pure LDPE, especially the composites with pseudocubic hematite particles of well-defined shapes. The results of this study indicate that LDPE/hematite composites can be promising materials for a wide range of applications, especially as packaging materials where improved thermal and mechanical properties as well as resistance to ultraviolet (UV) irradiation are required. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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

In this study, silane grafted and moisture cross-linked low density polyethylene nanocomposite foams were prepared by melt mixing and batch foaming process and the effects of silane content, nanoclay content, foaming agent concentration and clay type (clay modified with vinyltriethoxysilane (VTES) and amino-propyltriethoxysilane on foaming efficiency and foam properties were investigated. The morphology and the efficiency of silane modification of modified clay were characterized by series of tests, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The results of Fourier transform infrared and thermogravimetric analysis showed that the silane modifiers were bonded to the surface of nanoclay through both physical and chemical bonds. According to XRD, these modifiers caused characteristic peak of clay to shift to lower angles, and make an increase in basal spacing. Gel content, density, scanning electron microscopy, compression, creep and rheological tests were used to determine the effect of different parameters on properties of cross-linked polyethylene foams. Results indicated that silane content has the significant effect on stress-strain behavior in compression mode. Compression set and creep deformation were affected by cell size and gel content. Furthermore, the rheological properties including complex viscosity, storage and loss modulus of unformed samples increased with the addition of silane and nanoclay content. [ABSTRACT FROM AUTHOR]

Nanoparticle incorporation in polymeric matrices to generate polymer nanocomposite with the intention of maximizing the "nano-effect" derived from the nanoparticles and minimizing the drawbacks of the polymer is an emerging field of research. In this study, low-density polyethylene (LDPE) was mixed with varying concentrations of montmorillonite (MMT) nanoclays to create a polymer nanocomposite with desirable characteristics. Composite sheets with nanoclays contents of (0, 1, 2, 3, and 4 wt%) were prepared for hardness, tensile-fractography, thermal conductivity, and tensile testing (elongation and stress-at-break). The results showed that, according to scanning electron microscope (SEM) study, LDPE has a low flexibility temperature and is prone to corrosion. For larger MMT filler loadings (>3% wt), tensile-fractography showed nanoclays particle micro-aggregation. The pure LDPE sample fracture's tensile-fractography showed plastic deformation. MMT/LDPE samples with 3% wt hard MMT filler have brittle fractures without appreciable plastic deformation. Thermal conductivity test results show that LDPE/MMT composite thermal conductivity decreased with increasing clay concentration. The thermal conductivity values were reduced from a value of 0.13 W/m.K to a value of 0.039 W/m.K when reinforced with 0% wt to 3% wt filler loading, respectively. With 4% wt filler loading, LDPE/MMT composites had the highest shore hardness at 47.4. Yet, tensile tests indicated that increasing clay content improved the composite's characteristics. At modest loading percentages (1-2 wt%), tensile results were excellent. Furthermore, the elongation at break of the unadulterated LDPE was reduced by 20% and 30% after introducing 1% wt and 2% wt of MMT as reinforcement additives, respectively. Hence, MMT clay can improve the mechanical properties and thermal insulation of LDPE polymer matrix. [ABSTRACT FROM AUTHOR]

In this study, natural rubber (NR) and low-density polyethylene (LDPE) were melt blended in a 2-roll mill to fabricate NR/LDPE composites with liquid natural rubber (LNR) and hematite (α-Fe2O3) as compatibilizer and filler respectively. The effects of liquid natural rubber (LNR) on the mechanical properties and morphology of NR/LDPE composites were investigated. NR/LDPE composites were prepared in three different compositions of 70/30, 50/50 and 30/70, with filler content at varying concentrations (3, 5 and 7 g) while LNR was kept at 10 g for the modified composites. Results obtained showed increment in the tensile strength, tensile modulus, compressive and flexural properties but with decrease in the elongation at break the α-Fe2O3 and LDPE contents increase. The modification of the composites with LNR further enhanced the mechanical properties. FTIR spectrum of LNR revealed a peak at 3395 cm-1 suggesting the hydroxyl (OH) end group attached to the LNR chain due to the photochemical degradation of NR to yield LNR. FTIR spectra of the selected composites showed the presence of iron oxide bond (Fe-O) at 571 cm-1, 467 cm-1 and 463 cm-1 due to the incorporation of α-Fe2O3 filler particles in the composites. SEM images showed improved matrix/filler interfacial adhesion induced by the LNR compatibilizer. [ABSTRACT FROM AUTHOR]

Cellular polymers, such as polyethylene foams, are commonly used in the packaging industry. These materials have short service life and generate a high volume of waste after use. In order to valorize this waste and produce added‐value applications, it is proposed to convert these materials into highly efficient energy absorption structures. This was done by modifying the original cellular morphology of the foams (spheroidal or polygonal) into a re‐entrant structure to produce auxetic materials. This work presents an optimized process combining mechanical compression and solvent vapor evaporation‐condensation leading to low density foams (77–200 kg/m3) having negative Poisson's ratios (NPR). Three series of recycled low density polyethylene (LDPE) foams with an initial density of 16, 21, and 36 kg/m3 were used to optimize the processing conditions in terms of treatment temperature, time, and pressure. From all the samples prepared, a minimum Poisson's ratio of −3.5 was obtained. To further characterize the samples, the final foam structure was analyzed to relate with mechanical properties and compare with conventional foams having positive Poisson's ratios. The results are discussed using tensile properties and energy dissipation which were shown to be highly improved for auxetic foams. Overall, the resulting foams can be used in several applications such as sport and military protection equipment. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the possibility of reusing industrial scraps of Surlyn® ionomer by obtaining blends with Low-Density Polyethylene (LDPE). Blends of LDPE and Surlyn® scraps were obtained by extrusion with compositions ranging from 25 to 75 wt% of the ionomer. Their melt flow index (MFI), morphology (SEM), mechanical (tensile, flexural, impact tests) and thermal properties (DSC, TGA, HDT tests) were analyzed. The morphology of the blends presented two phases, indicating the immiscibility of phases. Surlyn® incorporation promoted a decrease in the degree of crystallinity of LDPE and a slight increase in the thermal decomposition temperature. In addition, Surlyn® decreased the decomposition rate of LDPE. However, the decrease in the degree of crystallinity did not affect the mechanical properties of the blends. Incorporating ionomer in LDPE promoted an increase in tensile and flexural strength, tensile and flexural modulus and strain at break. Impact strength decreased with increasing ionomer concentration.

Keywords: ; ; ; ; ; Okra bast fibers; corn husk fibers; agro-residual fibers; thermal properties; mechanical properties ZH EN Okra bast fibers corn husk fibers agro-residual fibers thermal properties mechanical properties 9101 9110 10 11/21/22 20221220 NES 221220 Introduction Maize ( I Zea mays L i .) Physical and mechanical properties of alkalized okra bast and corn husk fibers obtained via alkalization HT

A new type of imitation rattan was developed via a two-step method that used modified wheat straw as the raw materials and low-density polyethylene to make up wood plastic composite. Post-modification, a graft condensation reaction was carried out between silane as a coupling agent and wheat straw powder, which improved the thermal stability of the composite. A high level of contact and interaction at the fibre-matrix interface was observed. The optimum formula for the first step was 80% wheat straw powder, 4% silane coupling agent, and 16% calcium carbonate, with a modification temperature of 120 °C sustained for 10 min. For the second step, the mechanical properties had been greatly improved with the addition of modified wheat straw fibre and maleic anhydride grafted polypropylene (MA-g-PP). The use of 10% modified straw fibre and 5% MA-g-PP exhibited the highest tensile strength (8.75 MPa) and highest melt index (2.86 g/10 min). In particular, the MA-g-PP had an extremely advantage to the elastic modulus of wheat straw imitation rattan. The elastic modulus reached the maximum value of 2761.70 MPa at the amount of MA-g-PP added reached 5%. Our present study indicated the innovation of a new type of imitation rattan, which provides a new choice for utilizing wheat straw as industrial raw material, and other agricultural by-products containing liginocellulose could be used in a similar way. [ABSTRACT FROM AUTHOR]

Thermoplastic elastomers (TPE) based on ground tire rubber (GTR) are good strategies for the circular economy and sustainable development of waste tire rubber recycling. However, several parameters must be optimized to produce valuable TPE. The most important ones are GTR concentration and dispersion, as well as crosslinking degree, combined with interfacial interactions between the GTR and the thermoplastic matrix. In this work, TPE based on highly filled linear low‐density polyethylene (LLDPE) with GTR (50%–90%) was prepared via dynamic vulcanization. In particular, different reclaimed GTR (RR) was used alone or with a compatibilizer (maleic anhydride grafted polyethylene, PE‐g‐MAH) to prepare compatibilized TPE. The interactions between the rubber and plastic were quantified by a series of characterizations including mechanical tests, rheological measurements, differential scanning calorimetry, dynamic mechanical analysis and scanning electron microscopy. The results showed that the mechanical properties and processability decreased with increasing GTR content. Although the interfacial compatibility was improved with a higher GTR reclamation degree, the TPE mechanical properties were still gradually decreasing. To improve on these results, PE‐g‐MAH was added to increase the GTR‐LLDPE interfacial interactions. The results showed improvement in terms of mechanical properties and processability, especially for compatibilized TPE based on RR (tensile strength increased from 3.34 to 4.82 MPa and elongation at break from 91% to 101%). [ABSTRACT FROM AUTHOR]

The main goal of this work was to assess the technical feasibility of palm rachis (PR) as a reinforcing agent in the production of wood–plastic composites. Recycled linear low-density polyethylene/PR fiber composites were prepared at constant content (3 phc (per hundred compounds)) of maleic anhydride-grafted polyethylene as compatibilizer by melt blending method utilizing a two-roll mill and compression molding. The effect of nanosilica (NS), nanoclay (NC), and hybrid nanoparticles (NSNC) at different concentrations (2, 4, and 6 phc) on mechanical, physical, thermal, and morphological properties was investigated. The results of mechanical properties measurements demonstrated that when 6 phc NS, 4 phc NC, and 4 phc NSNC were added, tensile, modulus strength, and hardness reached their optimum values. At a high level of NC loading (6 phc), the increased populace of NC layers led to agglomeration and stress transfer gets restricted. Elongation at break and Izod impact strength were decreased by the incorporation of different nanoparticles. Water absorption and thickness swelling of prepared composites were found to decrease on the incorporation of NS and NC. In addition, the thermal stability showed slightly improved by the addition of nanoparticles, but there are no perceptible changes in the values of melting temperature by increasing the content of NS and NC or NSNC. Scanning electron microscopy study approved the good interaction of the PR fibers with the polymer matrix as well as the effectiveness of NS and NC in the improvement of the interaction. The finding indicated that wood–plastic composite treated by NS had the highest properties than other composites. [ABSTRACT FROM AUTHOR]

Rice husk ash (RiHA) was employed as the bio - originated and inexpensive filler prepared from agricultural wastes for reinforcing high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE). X-ray fluorescence (XRF) spectroscopy showed ∼80.82% for the silica content of RiHA as well as the values of other components present in this bio-based filler. The composites were obtained via melt mixing followed by the compression molding by the hot press forming. Characterization of the composites by FT - IR spectroscopy revealed that the filler has the sheer effects on the vibrational bands of the polymers. The usage of X-ray diffraction (XRD) analysis to investigate the d - spacing values and the crystallinity of the samples, exhibited the increase of d - spacing upon reinforcing the polymers with RiHA. The scanning electron microscopy (SEM) images showed an average size of 32 µm for the irregular RiHA particles which uniformly dispersed in the polymeric matrices. The energy dispersive X-ray (EDX) analysis displayed C, O, and Si as the main constituting elements of the composites and alternatively confirmed the well dispersion of the filler particles into the polymer matrices. The mechanical measurements showed the significant improvements in Young's modulus, yield stress, and hardness results of the polymers after reinforcing with the rice husk ash. For example, Young's modulus of HDPE was increased ∼15% after incorporating 7 wt.% of RiHA into this polymer. These mechanical properties of the polymers were increased upon increasing the RiHA content, while the parameter of elongation at break was decreased. [ABSTRACT FROM AUTHOR]