High Density Polyethylene Composites Research Articles

Enhanced thermal properties of tensile-aligned chopped carbon Fiber/HDPE composites for one-directional thermal ventilation

This study was aimed at enhancing the thermal properties of unidirectional chopped carbon fiber (CCF)/high-density polyethylene (HDPE) composites for applications requiring unidirectional heat dissipation. CCF/HDPE composite samples were fabricated using a special post-extrusion tension alignment method. The influence of different manufacturing variables, including fiber content, length, and draw ratio (DR, representing the tension), on the thermal conductivity was examined. Moreover, the response surface methodology (RSM) was used to investigate the influence of the manufacturing process variables. Results indicated that the thermal conductivity increased with increasing CCF wt.% and DR. The increase in DR promoted fiber alignment, contributing to enhanced thermal conductivity in the aligned direction. Additionally, the thermal conductivity increased with the increase in the CCF length. The proposed approach can facilitate efficient heat management in automotive and aerospace industries.

Exploring the Effects of Nano-CaCO3 on the Core-Shell Structure and Properties of HDPE/POE/Nano-CaCO3 Ternary Nanocomposites.

To address the dilemma of the stiffness and toughness properties of high-density polyethylene (HDPE) composites, titanate coupling agent-treated CaCO3 nanoparticles (nano-CaCO3) and ethylene-octene copolymer (POE) were utilized to blend with HDPE to prepare ternary nanocomposites via a two-sequence-step process. Meanwhile, a one-step process was also studied as a control. The obtained ternary nanocomposites were characterized by scanning electron microscopy (SEM), Advanced Rheometrics Expansion System (ARES), Dynamic Mechanical Analysis (DMA), wide-angle X-ray diffraction analysis (WXRD), and mechanical test. The SEM results showed one or two CaCO3 nanoparticles were well-encapsulated by POE and were uniformly dispersed into the HDPE matrix to form a core-shell structure of 100-200 nm in size by the two-step process, while CaCO3 nanoparticles were aggregated in the HDPE matrix by the one-step method. The result of the XRD showed that the nano-CaCO3 particle played a role in promoting crystallization in HDPE nanocomposites. Mechanical tests showed that the synergistic effect of both the POE elastomer and CaCO3 nanoparticles should account for the balanced performance of the ternary composites. In comparison with neat HDPE, the notched impact toughness of the ternary nanocomposites of HDPE/POE/nano-CaCO3 was significantly increased. In addition, the core-shell structure absorbed the fracture impact energy and prevent further propagation of micro-cracks, thus obtaining a higher notched Izod impact strength.

Highly Efficient and Eco-Friendly Thermal-Neutron-Shielding Materials Based on Recycled High-Density Polyethylene and Gadolinium Oxide Composites.

Due to the increasing demands for improved radiation safety and the growing concerns regarding the excessive use of plastics, this work aimed to develop effective and eco-friendly thermal-neutron-shielding materials based on recycled high-density polyethylene (r-HDPE) composites containing varying surface-treated gadolinium oxide (Gd2O3) contents (0, 5, 10, 15, and 20 wt%). The results indicate that the overall thermal-neutron-shielding properties of the r-HDPE composites were enhanced with the addition of Gd2O3, as evidenced by large reductions in I/I0, HVL, and TVL, as well as the substantial increases in ∑t and ∑t/ρ of the composites. Furthermore, the results reveal that the values for tensile properties initially increased up to 5-15 wt% of Gd2O3 and then gradually decreased at higher contents. In addition, the results show that the addition of Gd2O3 particles generally increased the density (ρ), the remaining ash at 600 °C, and the degree of crystallinity (%XC) of the composites. This work also determined the effects of gamma irradiation on relevant properties of the composites. The findings indicate that following gamma aging, the tensile modulus slightly increased, while the tensile strength, elongation at break, and hardness (Shore D) showed no significant (p < 0.05) differences, except for the sample containing 5 wt% of Gd2O3, which exhibited a noticeable reduction in elongation at break. Furthermore, by comparing the neutron-shielding and mechanical properties of the developed r-HDPE composites with common borated polyethylene (PE) containing 5 wt% and 15 wt% of boron, the results clearly indicate the superior shielding and tensile properties in the r-HDPE composites, implying the great potential of r-HDPE composites to replace virgin plastics as effective and more eco-friendly shielding materials.

Developing Eco-Friendly 3D-Printing Composite Filament: Utilizing Palm Midrib to Reinforce High-Density Polyethylene Matrix in Design Applications.

Designers actively pursue the use of novel materials and concepts in furniture and interior design. By providing insights into their processing behavior and suitability for 3D-printing processes, this research helps to highlight the potential of using waste materials to create more environmentally friendly and sustainable 3D-printing filaments that can be used in furniture and interior design. Furthermore, the study evaluates the effect of incorporating palm midrib nanoparticles (DPFNPs) to reinforce a high-density polyethylene (HDPE) matrix with different loadings such as 10, 20, 30, 40, and 50 wt.%. The composites were extruded into filaments using a manual extruder, which was then utilized to fabricate 3D-printed specimens using a 3D-printing pen. The effect of adding DPFNPs on the composite's chemical, thermal, and mechanical properties was evaluated, with a particular focus on how these modifications influence the melt flow rate (MFR) and, subsequently, the material's printability. The results revealed that HDPE and filament composites presented similar FTIR spectra. On the other hand, the filament composites presented an increase in the thermal stability and a decrease in the mechanical strength with increasing DPFNP content in the HDPE matrix. The filaments were successfully printed using a 3D-printing pen. Thus, using DPFNPs in the HDPE matrix presents a low-cost alternative for filament production and may expand 3D-printing applications in interior and furniture design with more sustainable materials. Future work will delve into optimizing these composites for improved printability and assessing their recyclability, aiming to broaden their applications in 3D printing and beyond.

Assessing the recycling potential of thermosetting polymer waste in high-density polyethylene composites for safety helmet applications

Abstract The rising demand for thermosetting polymers has resulted in the production of large amounts of industrial waste. Environmental issues due to waste landfills and increased raw material costs for new product development have led to the development of innovative recycling methods. This study focuses on the development of a product (helmet shell) by reinforcing thermosetting polymer waste (TPW) as a filler in a high-density polyethylene (HDPE) matrix. The HDPE and TPW were converted into extrudates using a twin-screw extruder. Then, the extrudate was pelletized to use as raw material for the injection molding machine. The HDPE/TPW composites were fabricated using injection molding. Maleic anhydride-grafted polyethylene was employed as a compatibilizer. In the composite, the TPW volume was reinforced at various weight percentages, ranging from 0 to 35 wt%. The mechanical, thermal, and viscoelastic properties of the composites can be enhanced by uniformly dispersing TPW in the HDPE matrix. However, it is difficult to achieve uniform dispersion at higher TPW volumes owing to the agglomeration effect. According to these findings, the mechanical properties were enhanced by up to 30 wt% addition of TPW. The findings suggest that the proposed composite has sufficient mechanical properties to be suitable for the fabrication of helmet shells.

Effects of chemical treatment and gamma-ray irradiation on the structure-properties of sunn hemp and okra hessian cloth reinforced high-density polyethylene composites: A comparative study

Okra hessian cloth and Sunn hemp hessian cloth were prepared and treated with 5, 10, and 15 wt% alkali solutions for 1 h. The optimized concentration of alkali is 10 wt%. The untreated and treated hessian cloths reinforced high-density polyethylene (HDPE) composites were then prepared using the compression molding method. Alkali-treated, and 55 wt% fiber contents reinforced composites showed improved mechanical properties among 40, 45, 50, 55, 60, and 65 wt% fiber contents composites. 55 wt% fiber contents reinforced composites were then irradiated under gamma-ray at doses 2.5–7.5 kGy at the rate of 6 kGy/h. According to the X-ray diffraction analysis results, only alkali-treated Okra reinforced, and Sunn hemp-reinforced HDPE composites had higher crystallinity values than untreated and irradiated composites. Surface micrographs showed that the Okra-HDPE and Sunn hemp-HDPE had better matrix and fiber attachment. Cross-linking between the two varieties of fibers and matrix was seen using Fourier-transform infrared (FTIR) spectroscopy. Both irradiated composites exhibited greater hydrophobicity in their water intake characteristics compared to untreated and alkali-treated composites. The tensile strength ( TS) value of Sunn hemp composite for 5 kGy gamma-ray irradiation dose is 68 MPa, which is 14% and 42% higher than that of treated and untreated composites, respectively. For comparison, the TS value for 5 kGy dose irradiated Okra composite is 66 MPa, which is 17% and 44% higher than that of treated and untreated composites, respectively. Young’s modulus ( Y) values of irradiated Okra composite and irradiated Sunn hemp composite showed higher values than that of other composites. Both irradiated composites have better thermal and structural characteristics than untreated and alkali-treated composites.

The impact of chemical treatment and gamma-ray irradiation on the okra hessian cloth reinforced high-density polyethylene composites

Okra hessian cloth-reinforced high-density polyethylene (HDPE) thermoplastic composites were prepared and characterized with both raw and alkali-treated fibers. The fiber contents were optimized for both the raw Okra thermoplastic composites and the alkali-treated Okra thermoplastic composites, and the optimum value of fiber content was 55 wt%. Samples that were alkali-treated and had 55 wt% fibers were subsequently exposed to gamma radiation at doses of 2.5, 5, and 7.5 kGy. Only the sample subjected to 5 kGy showed improved performance. Treated composites exhibited higher crystallinities than the untreated samples as observed by X-Ray diffraction analysis. The rupture surface micrographs of the composites exposed to 5 kGy gamma radiation revealed more compact than others. By using Fourier transform infrared spectroscopy analysis of composites, it was found that 5 kGy dose sample showed enhanced cross-linking between Okra fibers and HDPE matrix. The irradiated composite showed less water intake than the alkali-treated samples. Composites subjected to 5 kGy gamma rays showed improved tensile strength and Young’s modulus of values 66 MPa and 1925 MPa, respectively. Compared to raw and treated composites, the irradiated composites with a radiation dose of 5 kGy showed improved structural, mechanical, and thermal properties.

Tribological performance analysis of sustainable basalt micro-filler loaded bio-based polypropylene and high density polyethylene composites

Tribological performance analysis of sustainable basalt micro-filler loaded bio-based polypropylene and high density polyethylene composites

A case study on the rotomolding behavior of black tea waste and bio-based high-density polyethylene composites: Do active compounds in the filler degrade during processing?

This study verified the possibility of using waste material from the food industry (black tea) as functional filler of rotomolded biobased high-density polyethylene-based composites. As part of the experimental work, the influence of the materials preparation, i.e., dry blending versus twin-screw extrusion, on the effectiveness of the stabilizing antioxidant effect of the black tea was analyzed. The aim of the work was to verify whether, despite the initial degradation of the structure of the lignocellulosic filler, it would be possible to keep its antioxidant capacity and the stabilizing effect on the polyethylene matrix. The research showed that the filler allowed to stabilize the polymeric matrix during the rotomolding process, despite the appearance of numerous defects in the form of pores and a reduction in mechanical properties, more significant for composites prepared by dry blending, obtaining elastic modulus drops of about 50 %. Furthermore, the pre-processing step by melt mixing results in a significant improvement of the composite's thermo-oxidation stability, with increases in the oxidation induction time (OIT), from 25 min for the HDPE to over 70 min for composites with 5 % black tea, and improved rheological behavior, preventing the crosslinking of the matrix, indicative of its thermo-oxidative degradation. The tea brewing process caused the decrease of antioxidant activity of the filler; however, it did not significantly affect the antioxidant behavior, maintaining its influence on the polymeric matrix when the material is prepared via twin-screw compounding, which was proved to provide better stability, increasing OIT by approximately 20 min later when compared to dry blending.

Enhanced Thermal Conductivity of High-Density Polyethylene Composites with Hybrid Fillers of Flaky and Spherical Boron Nitride Particles.

The synergistic effect between different fillers plays a crucial role in determining the performance of composites. In this work, spherical boron nitride (BN) and flaky BN are used as hybrid fillers to improve the thermal conductivity (TC) of high-density polyethylene (HDPE) composites. A series of HDPE composites were prepared by adjusting the mass ratio (1:0, 4:1, 2:1, 1:1, 1:2, 1:4, and 0:1) of spherical BN and flaky BN. The SEM results indicate that the spherical BN (with a particle size of 3 μm) effectively filled the gaps between the flaky BN (with a particle size of 30 μm), leading to the formation of more continuous heat conduction paths with the composite. Remarkably, when the mass ratio of spherical BN to flaky BN was set to 1:4 (with a total BN filling amount of 30 wt%), the TC of the composite could reach up to 1.648 Wm-1K-1, which is obviously higher than that of the composite containing a single filler, realizing the synergistic effect of the hybrid fillers. In addition, the synergistic effect of fillers also affects the thermal stability and crystallization behavior of composites. This work is of great significance for optimizing the application of hybrid BN fillers in the field of thermal management.

Molecular Dynamics Study of the Diffusion of Helium in High-Density Polyethylene Composites Reinforced with Monocrystalline and Bicrystalline Hexagonal Boron Nitride Nanosheets: Implications for Helium Storage

Molecular Dynamics Study of the Diffusion of Helium in High-Density Polyethylene Composites Reinforced with Monocrystalline and Bicrystalline Hexagonal Boron Nitride Nanosheets: Implications for Helium Storage

Ionizing Radiation Shielding Properties of Tantalum Pentoxide Doped High-Density Polyethylene Composites: A Theoretical Study

The rise in the utilization of radiation across various domains necessitates the advancement of next-generation radiation shielding materials that are devoid of lead. Due to their low weight and flexibility, polymer composites are considered as environmentally friendly alternative materials that can be used instead of toxic and high-weight lead for radiation shielding. From this point of view, the present study has focused on examining the radiation shielding performance of tantalum pentoxide doped high-density polyethylene (HDPE/Ta2O5) composites (including 5, 10, and 20 wt% Ta2O5) by using WinXCom software and MCNP6 simulation. The photon energies selected corresponded to the photons emitted from the Ba-133 (81 and 356 keV), Cs-137 (662 keV), and Co-60 (1173 and 1332 keV) radioactive sources that cover X-rays along with the low-and mid-energetic gamma-rays. The mass attenuation coefficient (/) of the composites has been calculated within the 81 keV-1332 keV photon range by utilizing WinXCom software and MCNP6 code. The other shielding parameters such as Half Value Layer (HVL), effective atomic number (Zeff), and effective electron density (Neff) have been determined. In the light of data, it has been revealed that gradual increase in Ta2O5 doping while improving the / coefficients, Zeff, and Neff parameters, decreasing the HVL length of HDPE considerably. Additionally, the parameters obtained by WinXCom and MCNP6 simulation are in good agreement. the. Ultimately, the best ionizing shielding performance among the composites has been determined for HDPE/20% Ta2O5 composite against 81 keV photons.

Experimental investigations on the influence of natural reinforcements on tribological performance of sustainable nanocomposites: A comparative study with polymer technology

Sustainable polymer-based nanocomposites are gaining consideration as a potential alternative to conventional composites in tribological applications. The research aimed to study the influence of reinforcements on the tribological response of sustainable polymer-based nanocomposites. In this work, nine different nanocomposites were developed by the recycling of waste plastics of three different types with incorporation of coconut fibers, jute fibers and nano-sized particles of rice husk ash. Three-body abrasive wear behaviour at five different conditions of loads and speeds were investigated. The wear of the composites increases invariably with the applied loads and speeds, and were in the ranges of 0.0154–0.2212 (cm3) and 0.02207–0.4398 (cm3), respectively. The comparative analysis of the three-body abrasive wear at the conditions of speeds has suggested the reinforcement of coconut fibers with low-density polyethylene for optimum tribological performance, whereas reinforcement of rice husk ash showed an excellent wear resistance for high-density polyethylene and polypropylene composites. The observations for three-body abrasive wear under the considered loads has suggested the incorporation of coconut fibers with low-density polyethene and polypropylene composites, whereas rice husk ash is a suitable reinforcement with high-density polyethene for optimum tribological performance. The rolling behaviour of the nanoparticles has considerably enabled the tribological performance of nanocomposites at extreme conditions of loads and speeds. The research indicated a great potential for natural reinforcement in nanocomposites and will promote the expansion of sustainable polymer-based nanocomposites for tribological applications.

The Functional and Biodegradation Characteristics of High-Density Poly-ethylene, Poly-caprolactone and Poly-ethylene Maleic Anhydride Composites

The goal of this research is to develop environmental friendly polymer composites in order to reduce the use of current polymers and promote global security. High density poly-ethylene (HDPE) and poly-caprolactone (PCL) composites were mixed with varying amounts of poly-ethylene joined maleic anhydride (PE-g-MA) as a strong compatibilizer. The different composites were prepared using the conventional infusion shaping approach. Mechanical properties were accounted for to have good increase for the diverse compositions and the strength and pliable strain% (stretching) rate at break were improved in comparison to unadulterated HDPE. Examining electron magnifying lens (SEM) morphology revealed that the expansion of PE-g-MA increased the compability and so aided in the achievement of a synergistic mix of superior qualities. The manure internment test yielded favorable bio-corruption results and demonstrated the fertilizer's ability to enable bio-debasement of various composites, allowing their utilization as key polymers in the assembly of single-use products and also protecting nature and acting as a decent waste administration of HDPE polymer.

Innovative HDPE Composites Enriched with UV Stabilizer and Diatomaceous Earth/Zinc Oxide for Enhanced Seafood Packaging and Antimicrobial Properties.

The fisheries industry encounters distinct packaging challenges, including the need to protect perishable seafood from rapid spoilage caused by UV radiation while allowing for reuse. This study tackles these issues by introducing advanced high-density polyethylene (HDPE) composites enhanced with a UV stabilizer and inorganic fillers, such as diatomaceous earth/zinc oxide (DZ). Our investigation explores the transformative effects of weathering on these pioneering composites, evaluating shifts in mechanical, physical, thermal properties, and sub-zero temperature stability. Incorporating a UV stabilizer alongside DZ within the HDPE matrix significantly enhances mechanical performance and weathering resilience. These enhancements extend the longevity of seafood packaging while preserving product quality. Moreover, our findings reveal a substantial breakthrough in antimicrobial properties. The inclusion of DZ, with or without a UV stabilizer, results in an impressive up to 99% enhancement in antibacterial activity against both Gram-positive and Gram-negative bacteria. This discovery not only bolsters the protective attributes of HDPE packaging but also presents a compelling case for the development of active packaging materials derived from DE/ZnO composites. This study bridges the gap between packaging and seafood quality, introducing advanced polymeric packaging technology for seafood products. It highlights the mutually beneficial link between packaging improvements and ensuring seafood quality, meeting industry needs while promoting sustainability.

Effect of gamma irradiation on tensile, thermal and wettability properties of waste coffee grounds reinforced HDPE composites

Abstract This study investigates the impact of gamma irradiation on the properties of waste coffee grounds (WCG)/high-density polyethylene (HDPE) composites. The composites were manufactured with 20 wt% of unirradiated and irradiated WCG at 10 and 20 kGy doses of gamma radiation. Through the utilization of a two-roll mill followed by a hydraulic press. The properties of the composites were analyzed through several methods, including contact angle measurements, hardness and tensile tests, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), in order to understand the influence of gamma irradiation. The addition of WCG decreased the tensile strength of the composite. However, gamma irradiation at 10 and 20 kGy led to substantial improvements in thermal stability and tensile strength compared to unirradiated samples. The SEM images showed the alterations within the fiber-matrix interface that corroborated the enhanced tensile properties after the treatment. While FTIR spectra confirmed the changes in functional groups of WCG caused by the irradiation process, gamma irradiation treatment not only increases fiber-matrix adhesion but also significantly improves the water resistance of the composites. These results suggest that gamma irradiation can be used for the modification of agro-waste materials as a beneficial process and the fabrication of high-performance, environmentally friendly composites.

Thermal buckling behavior of 3D printed foams: Plain, graded, and sandwich variants

The present work focuses on the experimental investigation of the thermal buckling response of 3D printed functionally graded glass micro balloon (GMB) reinforced high density polyethylene (HDPE) composites and their respective sandwiches under non-uniform heating conditions. The influences of GMB loading and its graded composition on temperature distribution are analyzed. The reinforcement of hollow GMB rendered lower thermal conductivity due to enhanced thermal resistance with an increase in filler percentage. An increased thermal buckling strength is also observed. Due to their non-uniform thermal expansion, functionally graded sandwich beams exhibited less deflection than plain beams. Among the cases of three heating conditions (One end heating: case-1, Center heating: case-2, both end heating: case-3), maximum deflection is observed in case 2 while the minimum deflection is noted in case 1. These printed foams can be utilized for lightweight thermal insulating pipes.

Enhanced strength and synergistic flame retardancy of PE-base nanocomposites with coating-modified palygorskite clay

Polyethylene (PE) - base nanocomposites composed of high density polyethylene (HDPE) as matrix and coating-modified palygorskite clay (MAT) as functional filler and fire resistance was prepared by melt blending method. The MAT powder was prepared by solution heterogeneous precipitation method combined with spray drying processes. The microstructure observation shows that the particle size of the obtained MAT powder was concentrated and even. Both mechanical properties and thermal behaviors of the nanocomposites containing MAT were compared to those with commercial ceramic fillers (naming as S type flame retardants) at the same addition mass ratios level. The added MAT mass fractions in the composite were defined as 5 wt%, 10 wt%, 15 wt%, and 20 wt%, respectively. When the addition amount of MAT is 15 wt%, the impact toughness of MAT/HDPE composites approaches 13.41 kJ/m2, which is better than that with commercial fillers. The added fractions of MAT increases to 19.1 wt%, and the elongation at break of nanocomposite reaches 495%, which is much higher than that with S type flame retardants. The differential scanning calorimeter (DSC) test results show that MAT can enhance the melting point range of HDPE and improve the thermal stability of the composite. The LOI (limiting oxygen index) results confirm that MAT can effectively improve the flame retardancy of HDPE composites, and the LOI value increases with the MAT addition. The enhancement of mechanical and thermal properties of the PE-base composite is essentially originated from the uniform dispersion of MAT in polymer matrix and the strong interactions with inorganic – organic interface compatibility.

Thermoformability study of wood flour–HDPE composites with variations in wood content under vacuum forming

Wood–plastic composites (WPCs) have emerged as sought-after substitutes for plastic. However, their use is restricted primarily to linear profiles owing to the lack of techniques for their three-dimensional (3D) forming. Thermoforming is a potential method for the 3D formation of WPCs. Accordingly, the aim of this study was to evaluate the thermoforming behaviour of extruded wood flour–high-density polyethylene composites with two different wood flour compositions (34 % and 54 %) under vacuum forming. This study examined the thermal behaviour of each structure during the forming process and the shape conformability, shape consistency, and surface quality of the formed samples. The findings suggest that increasing the quantity of plastic in composites can improve the obtained shape dimensions. Nevertheless, this improvement is accompanied by an increased level of inconsistency in the acquired profiles due to the distinct stretching rates of plastic and wood. Furthermore, the results reinforced the reliability of thermal analysis as a credible means of evaluating quality.

Electric Field Analysis of HDPE/NR Biocomposite Due to Moisture Content Condition

It is critical to develop new insulating materials that can improve the performance of next-generation high-voltage cables used in the construction of future electrical networks. The high electric field reduces solid insulation resistance and causes partial discharge through imperfections in a dielectric, causing the dielectric to age and eventually fail. Moisture is one of the most serious factors the effect the high voltage insulation status of High-Density Polyethylene (HDPE) composites. The main goal of this project is to investigate the electric field intensity of HDPE due to moisture content condition when mixed with 10g, 20g, and 30g of various bio-fillers such as coconut coir fibre, pineapple leaves fibre, and oil palm empty fruit bunch. This can be accomplished by using the Finite Element Method Magnetics (FEMM) 4.2 software to create a two-dimensional (2D) axisymmetric electrostatic model. When compared to unfilled HDPE, the inclusion of bio-filler in HDPE increased the maximum electric field intensity due to moisture content condition. The intensity of the electric field varied with the different percentages of biocomposite loading and their permittivity due to moisture content condition. The results showed, due to moisture content condition, the maximum electric field intensity was significantly lower when HDPE was added with a 10% loading of the oil palm empty fruit bunch (EFB). As a result, EFB bio-filler was the best composition because it tends to improve dielectric properties by having a lower maximum electric field intensity which is 4.214Mv/m due to moisture content condition at the top sphere electrode when compared to other compositions.