Properties Of High Density Polyethylene Research Articles

Studies on the Effects of Bentonite (Nanoclay) on the Mechanical Properties of High-Density Polyethylene

In this work, the effect of Bentonite (Nanoclay) on the mechanical and mor-phology properties of HDPE/Nanoclay composite pipe material was investi-gated. This led to the development of a composite material with improved me-chanical properties. The HDPE/nanoclay composites were produced using an injection moulding machine at 200?C and rotor speed of 50 rpm. The compati-bilizer used in this study was Polyethylene-graft-Maleic Anhydride. Different compositions of nanoclay reinforcements were prepared and added to HDPE resin. A particle size of 425 μm was used in proportions of 0%, 5%, 10%, 15%, and 20% on weight fraction basis. All the composites samples were characterized by Zwick Roell tensile testing machine and Scanning Election Microscopy (SEM). Experimental results obtained showed improvements in the tensile strength, and modulus at the expense of elongation. The maximum tensile strength and modulus was obtained at 10% filler composition. These enhanced properties are due to the homogenous dispersion of nanoclay in HDPE matrix, which is evident from the structure that was evaluated using SEM.

The use of volcanic particles in HDPE offers alternative filling material against CaCO3. Part II—scratch properties

This article clarifies that the influence of volcanic particles (VPs) and calcium carbonate particles (CaCO3) on the scratch behavior of high‐density polyethylene (HDPE). Melt compounding was carried out using a twin‐screw microcompounder and then injection molding with various VPs and CaCO3 contents such as 0, 6, 12, 18, and 24 wt% was performed for preparing test samples. Scratch testing was performed using the testing apparatus and methodology outlined in ASTM D7027–05 with 60 mm/min scratch velocities of 200 μm stainless steel ball bearing scratch tip. Coefficient of friction (COF) and scratch hardness values of various VPs‐ and CaCO3‐filled HDPE composites were determined. Results showed that COF and scratch hardness values were improved with higher inorganic particle concentrations. It was found that VPs was more effective filler for the scratch properties of HDPE than CaCO3. After scratch tests, scratch damage mechanisms were analyzed by scanning electron microscopy. POLYM. COMPOS., 40:2564–2572, 2019. © 2018 Society of Plastics Engineers

Mechanical Properties and Morphologies of High Density Polyethylene Reinforced with Calcium Carbonate and Sawdust Compatibilized with Vinyltriethoxysilane

In this study, the influence of vinyltriethoxysilane on the mechanical and morphological properties of high density polyethylene filled with calcium carbonate and sawdust were investigated. The fillers were treated with 2% (v/v) vinyltriethoxysilane before mixing with the high density polyethylene. The results showed that the modification of the fillers with the vinyltriethoxysilane promoted the adhesion between the matrix and fillers. All of fillers increased the modulus and tensile strength of the high density polyethylene composites but the %elongation at break decreased. Also, the fillers loading increased the mechanical properties of the composites. The mechanical properties of the high density polyethylene/calcium carbonate composite was higher than the high density polyethylene/sawdust composite. In addition, vinyltriethoxysilane with acted as the modifying agent of the fillers slight increased the mechanical properties of the composites. The factors that influencing the mechanical properties of the high density polyethylene composites were type of fillers, particle loading and vinyltriethoxysilane. In addition, the thermal properties of the high density polyethylene composite were related to type of fillers and vinyltriethoxysilane.

Flame sprayed environmentally friendly high density polyethylene (HDPE)–capsaicin composite coatings for marine antifouling applications

Marine biofouling has emerged as worldwide serious problems for artificial marine infrastructures. Among the measures taken so far to solve the abovementioned problems, construction of an antifouling layer has been proven to be effective in offering long-term antifouling performances. Antifouling based on the use of biocides is the most important method in modern maritime industries. While tributyltin (TBT)-based self-polishing coatings are being replaced by other biocide-releasing coatings, the environmental toxicity of these compounds is also under scrutiny. Therefore, there is a significant interest in developing non-toxic technologies. Green biocides can also be extracted from many types of organisms including terrestrial plants, sea creatures and bacteria. The capsaicin was extracted from chili pepper. In this study, flame sprayed high density polyethylene (HDPE)–capsaicin composite coatings were developed for marine antifouling applications. Capsaicin powder were fixed by polymer-based substrate and distributed evenly. Antifouling performances of the films were assessed by examining survival and colonization behaviors of E. coli and Bacillus sp. bacteria and Phaeodactylum tricornutum. Antifouling test indicated excellent antibacterial properties of HDPE–capsaicin composite coatings against both gram-negative Escherichia coli and gram-positive marine Bacillus sp. bacteria. Excellent antifouling performances against bacteria and algae of the thermal sprayed composite coatings give clear insight into their potential applications as environmentally friendly antifouling layers in the marine environment.

Effect of Selected Injection Conditions on the Mechanical Properties and Structure of HDPE

This paper is devoted to research of high-density polyethylene (HDPE), which belongs to one of three main biomaterial groups, i.e. polymeric materials. Hence, due to its unique properties, it still plays an important role in biomedical applications – especially in the production of medical equipment, implants and parts of prostheses. This publication deals with the effect of selected conditions of processing which involved injection moulding on the mechanical properties and structure of HDPE mouldings. Samples for tests were produced on a Krauss  Maffei injection moulder on the basis of a research plan prepared using the STATISTICA program. According to this schedule, the following variable parameters of the injection process were selected: injection temperature Tw [C], mould temperature Tf [C] and injection velocity vw [mm/s]. In addition, a part of the moldings was subjected to a few processings. Then the samples obtained were subjected to different tests: tensile, impact and hardness tests, Differential Scanning Calorimetry (DSC) and the melt flow rate (MFR) test in order to determine the influence of selected injection conditions and the multiplicity of processing on the mechanical, rheological and structural properties of HDPE.

Measurements of dielectric properties of High Density Polyethylene-Nano-Composites

Recently, polymers Nano-Composites for various important electrical apparatus are widely used. This paper studies the dielectric properties of high density polyethylene composed with different concentrations of clay-Nano-filler over a high frequency range of 200 to 2 MHz. This paper studies also the frequency and temperature dependence of relative permittivity (εr) and loss tangent (tan delta) of pure high density polyethylene and polymer composites with clay-Nano-filler of different concentrations over a high frequency range of 200 Hz to 2 MHz and a temperature range of 0–50 °C. The experimental results show that improvements are noticed in relative permittivity (εr), loss factor, insulation impedance and dielectric strength by the adding of Clay-Nano-Filler to the polymer material when compared with High Density Polyethylene without any additives. It has been seen that the dielectric properties of High Density Polyethylene-Nano-Composites at a certain Nano-Filler concentration have been improved. From the investigation of obtained results, it is concluded that additives of 6% filler concentration by weight is the optimum clay content for HDPE/Clay Nano-Filler material.

Permeability, Melt Flow Index, Mechanical, and Morphological Properties of Green HDPE Composites: Effect of Mineral Fillers

In this study, two types of composites, both with the same polymeric matrix, high density polyethylene (HDPE) from renewable sources, also called green HDPE, are investigated. The mineral fillers insert into HDPE are vermiculite and titanium dioxide (TIO2). The objective of this work is the evaluation of two inorganic fillers in the HDPE composites and how their presence alters the properties of this HDPE derive from sugar cane ethanol. Composites obtain by extrusion with different contents of anatase type titanium dioxide (10–30 wt%/wt) and brazilian vermiculite (5–20 wt%/wt) are evaluated as for mechanical and morphological properties, melt flow index (MFI), and permeability. The addition of fillers cause little influence on tensile strength, but increased the elasticity modulus and decreased impact strength. in relation to morphology, it is found that particles of TIO2 are well dispersed in the HDPE matrix. For composites with vermiculite, its distribution in the polymer matrix is not so good as compared with composites of TIO2, especially in proportions higher than 10 wt%. The results of MFI show that by adding vermiculite the fluidity of polyethylene does not change, but the addition of TIO2 promotes a reduction in fluidity thus suggesting that a good dispersion has been achieved. Permeability increases on the addition of the two fillers, being more pronounced at high amounts (20% vermiculite and 30% TIO2). The analyzed properties, the addition of these fillers does not interfere negatively the properties of the green HDPE and can be considered an alternative toward low cost composites.

IMPROVED SOME PROPERTIES OF HIGH DENSITY POLYETHYLENE SYNTHESIS USING FIBER GLASS FOR PIPES AND RESERVOIRS APPLICATIONS

In this paper, the effect of surface modification of short glass fiber on some properties ofhigh-density polyethylene composite was investigated. The chemical treatment of short glassfiber (SGF) with solvent ethanol was achieved, and composites with weight fraction (0.5, 2.5,4wt. %) were fabricated. Mechanical behavior tests include (tensile strength, impact, andhardness tests) and structure test (FTIR) were used. Values of mechanical tests for treatedshort glass fiber – reinforced High density polyethylene composites were much better thanthe neat high density polyethylene. The tensile strength value of composite from (37 to 41MPa), impact strength from (83 J/m² to 100 J/m²), and hardness from (64 to 86 N/m²). Resultof FTIR test showed physical reaction without the formation of new peaks.

The Effects of Nanoclay on Mechanical Properties of High Density Polyethylene and Polypropylene Materials

The Effects of Nanoclay on Mechanical Properties of High Density Polyethylene and Polypropylene Materials

Tuning of HDPE Properties for 3D Printing

The objective of this study is to improve high density polyethylene (HDPE) properties for 3D printing by addition of graphene and low density polyethylene (LDPE). Graphene was prepared by modified Hummer’s method. The prepared graphene was characterized by the infrared spectroscopy and the X-ray diffraction analysis (XRD). Graphene/HDPE and LDPE/HDPE composites were successfully prepared through the melt-blending technique using a twin-screw extruder. The melt flow index (MFI) and differential scanning calorimetry (DSC) were employed to characterize neat HDPE and the modified HDPE. FTIR and XRD results show that graphite was successfully changed into graphene completely and MFI of graphene/HDPE and LDPE/HDPE decreased as the amount of graphene and LDPE in the composite blends increased. DSC results show that the addition of low crystalline polymers can reduce a crystallization temperature and crystallinity content.

Synergetic effect of Posidonia oceanica fibres and deinking paper sludge on the thermo-mechanical properties of high density polyethylene composites

This study evaluated the reinforcement potential of Posidonia oceanica fibres (POF) and deinking paper sludge (DPS) on the thermo-mechanical properties of high density polyethylene (HDPE) binary and hybrid composites. The weight ratios of the fillers (POF and/or DPS) to the polymer were 0:100; 20:80; 30:70 and 40:60 (wt:wt). Maleated polyethylene (MAPE) was added at a proportion of 3% by weight. The chemical composition, structural and thermal properties and morphology of the fillers were investigated by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The mechanical (tensile and impact strength) and thermal properties (TGA and Differential Scanning Calorimetry (DSC)) of the binary and hybrid composites were also investigated. Binary and hybrid composite properties depend on the chemical composition of the fillers (POF and DPS), the filler/matrix interfacial adhesion and the POF: DPS ratio. The tensile modulus and strength of the binary and hybrid composites increased with increasing filler content (POF or/and DPS). A better interfacial adhesion between fillers and matrix was achieved in the presence of MAPE. HDPE/POF/MAPE composites achieved the highest tensile modulus and strength with 40% POF. But lower thermal stability, ductility and impact strength were found with the addition of the POF. However, the thermal stability, crystallinity, ductility and toughness improved in HDPE/POF/DPS/MAPE hybrid composites due to the addition of DPS or the substitution of POF by DPS.

Synthesis and Mechanical Characterization of High Density Polyethylene/Graphene Nanocomposites

The purpose of this work is to investigate the effects of graphene nanosheets (GNSs) addition on the mechanical and thermal properties of high density polyethylene (HDPE). The HDPE/Graphene nanocomposites were synthesized using solution blending approach. HDPE was incorporated with graphene nanosheets in a solvent at various weights of fractions (0.1, 0.2, 0.4 and 0.5 wt%), and then the micro-hardness, elastic modulus, tensile strength, strain at break and thermal properties of the nanocomposites were measured and compared. The results showed that the use of Xylene solvent at high temperature combined with mechanical stirring can fully dissolve HDPE pellets. Scanning electron microscope (SEM) showed that GNSs were homogenously dispersed in the polyethylene matrix at low weights of fractions. The addition of just 0.2 wt% GNSs resulted in 100% increase in the micro-hardness value. The elastic modulus and tensile strength properties are proportionally increased with increasing GNSs content up to 0.4 wt%. However, at higher weight of fraction, a reduction in these properties is observed. The crystallinity and strain at break properties are reduced with the addition of GNSs.

Dynamic and ballistic impact behavior of biocomposite armors made of HDPE reinforced with chonta palm wood (Bactris gasipaes) microparticles

The mechanical behavior of chonta palm wood (Bactris gasipaes) microparticles reinforced high density polyethylene (HDPE) under high strain-rate compressive and ballistic impact loading were investigated. The palm wood microparticles were introduced into the HDPE via an extrusion process using parallel twin screw extruder to produce biocomposite containing 10, 20, 25, and 30 wt % chonta wood microparticles. In addition to mechanical tests, fractographic analysis was done to understand the failure mechanism in the biocomposites under dynamic and ballistic impact loads. The results indicate that both quasi-static and dynamic mechanical properties of HDPE are enhanced by reinforcement with chonta palm wood particles. The biocomposites containing 25 wt % wood microparticles exhibited the highest strength, stiffness, ballistic impact resistance and impact energy absorption capability. Introduction of microparticles of chonta palm wood as reinforcement into a polymeric matrix such as HDPE is therefore a promising method to develop biocomposites with enhanced capacity to withstand dynamic impact loading and absorb impact energy.

Assessment of Bulk Mechanical Properties of HDPE Hybrid Composite Filled with 1D/2D Nanofiller System

Current work reports on evaluation of bulk mechanical properties of High Density Polyethylene (HDPE) reinforced with functionalized 1D (Multi Walled Carbon Nanotubes- (MWCNTs) and 2D (hexagonal-Boron Nitride Nanoplatelets-(h-BNNPs) fillers. Mechanical mixing and injection moulding technique was used to prepare the composites. Evaluation of bulk mechanical properties like hardness, yield stress, fracture stress, impact toughness and Young`s modulus was carried out. The optimum properties were exhibited by HDPE/0.25 MWCNT/0.1 BNNP. Hardness, yield stress, fracture stress, impact toughness and Young`s modulus was observed to increase by 93.84, 80.83, 59.23, 115 and 42.05% on comparison with pure HDPE. TEM images confirm the tubular and hexagonal morphology of MWCNT and h-BNNP. It is concluded from test results that addition of MWCNT and h-BNNP into HDPE has improvised mechanical properties.

Progress in Technology and Catalysts for Continuous Stirred Tank Reactor Type Slurry Phase Polyethylene Processes

High-density polyethylene (HDPE) have been widely used as materials of hollow molded articles, extrusion molded articles, films and sheets. The properties of HDPE vary depending on its application fields and processing methods thereof. Approximately 50 million tons of HDPE are produced annually around the worldwide by slurry phase processes. In this paper, the status of slurry phase polyethylene processes in China is briefly introduced. Two of the most important licensers of continuous stirred tank reactor (CSTR) type slurry phase polyethylene processes, namely, Hostalen (Licensed by Basell), CX (Licensed by Mitsui), with a dual- or three-reactor are reviewed. The merits and demerits of the examined polyethylene production technologies are discussed in detail. Catalyst is a key of polyolefin technology. It does have an extremely close relationship with the performance of polyethylene. The characteristics and disadvantages of different catalysts for the two processes are summarized for comparison, including the PZ and RZ catalysts of Mitsui, the BCH and BCE catalysts of Beijing Research Institute of Chemical Industry, the TH series catalysts of Basell. Some advices on the development and application of HDPE catalysts for the slurry process are proposed.

Assessment of nanoscopic dynamic mechanical properties and B-C-N triad effect on MWCNT/h-BNNP nanofillers reinforced HDPE hybrid composite using oscillatory nanoindentation: An insight into medical applications.

A thrust on improvement of different properties of polymer has taken a contemporary route with advent of nanofillers. Although several nanofillers are existent; MultiWalled Carbon Nanotubes- (MWCNTs) and h-Boron Nitride nanoplatelets-(h-BNNPs) unique combination of 1D and 2D dimensional geometry aids an advantage of B-C-N triad elemental effects on properties of tested samples. The current study aims to investigate the effects of MWCNT and h-BNNP reinforcement in High Density Polyethylene (HDPE) for high load bearing areas of medical applications requiring both elastic and viscous behavior. The results were analyzed keeping a view of its application in areas like HDPE based fracture fixation plates, acetabular cups and others. The composite and hybrid samples with different loadings were prepared after surface modification of nanofillers by mechanical mixing and molding technique. The dynamic nano-mechanical properties like storage modulus, loss modulus and tan delta were assessed for each sample during frequency swept from 10 to 220 Hz. The viscoelastic properties like hc/hm, H/E, elastic-plastic deformation were investigated and evaluated. At a frequency of 10 Hz, the storage and loss modulus of 0.1 CNT increased by 37.56% and decreased by 23.52% respectively on comparison with pure HDPE. This infers a good elastic as well as viscous behavior. Overall elastic behavior of 0.1 CNT was confirmed from tan delta evaluation. The interaction between B-C-N elemental triad had significant effect on creep strength, visco-damping property (hc/hm and H/E), elastic plastic displacement and pile-up and sink-in behavior. Highest creep strength and visco-damping property was exhibited by 0.25 CNT/0.15 BNNP hybrid. The elastic-plastic displacement of hybrid composite was noted as least, which decreased by 30% on comparison with pure HDPE. It can be inferred that presence of 1D-MWCNT and 2D-h-BNNP had significant effect on important dynamic viscoelastic and creep properties of HDPE based hybrid composites.

Novel high‐density polyethylene‐niobium pentoxide dielectric materials

This study for the first time reports the processing and properties of high‐density polyethylene (HDPE) reinforced with niobium pentoxide (Nb2O5) up to 40 wt%. In this work, Nb2O5 was chosen as reinforcement because of its advantageous properties such as good dielectric properties, high temperature stability and excellent biocompatible properties. Almost fully dense HDPE–Nb2O5 composites were prepared via hot pressing route. Both the hardness and dielectric properties of the HDPE increased significantly with the addition of Nb2O5. The hardness of HDPE increased from ∼37 to 60 MPa (i.e., by 62%) with the addition of 40 wt% Nb2O5. The dielectric constant and dissipation factor (dielectric loss) were found to increase with the increasing Nb2O5 content. We have achieved highest ever reported dielectric constant (ε') of 14.66 for HDPE–40 wt% Nb2O5 and the dielectric constant of HDPE is enhanced by 237% and shows the potential of Nb2O5 in improving the dielectric and hardness properties of HDPE. With increasing frequency there was slight decrease in the dielectric constant of HDPE–Nb2O5 composites, whereas not much change in the dielectric constant of pure HDPE. The dielectric constant (ε') of HDPE is 4.6 at 1 MHz, while the ε' value for the composite with 40 wt% Nb2O5 ceramic filler was found to be 13.2. The dielectric loss for the HDPE composites is higher than the neat polymer, particularly HDPE–40 wt% Nb2O5 composite measured with maximum dielectric loss (0.08) at 100 Hz. Nevertheless, the dielectric loss of HDPE materials significantly decreased with further increasing the frequency to 1 kHz and the dielectric loss even significantly lowered with increasing frequency to 1 MHz. The experimental values of dielectric constant show much better values than the calculated values based on theoretical models. The newly developed HDPE–Nb2O5 composites are showing much better dielectric properties than the reported literature values of HDPE materials. POLYM. COMPOS., 40:749–757, 2019. © 2018 Society of Plastics Engineers

Mechanical, Thermal and Crystallization Properties of Polypropylene (PP) Reinforced Composites with High Density Polyethylene (HDPE) as Matrix

Our work aims to evaluate a complete outlook of virgin high density polyethylene (HDPE) and polypropylene (PP) polyblends. Virgin PP of 20, 30 and 50 weight% is compounded with virgin HDPE. The properties like tensile strength, flexural strength, Izod impact strength are examined. Scanning electron microscopy (SEM) and polarised light microscopy (PLM) are used to observe the surface and crystal morphology. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) tests verify the non compatibility of both polymers. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques are used to study the thermal behaviour of composites. The results manifest co-occurring spherulites for polyblends; indicating the composite to be a physical blend of continuous and dispersed phases, but on the other hand PP improves the tensile and flexural properties of HDPE.

Process-induced morphology and mechanical properties of high-density polyethylene

Electron induced reactive processing (EIReP) is an emerging technology for the development of high performance polymer materials. It simultaneously combines the traditional electron beam (EB) treatment of polymers and their melt mixing in the presence of shear stresses and/or rates of deformation. In comparison to traditional EB treatment of high-density polyethylene (HD-PE) at room temperature, EIReP modified HD-PE shows an inhomogeneous morphology, a self-nucleation effect as well as a significant increased tensile strength and decreased elongation at break. In order to identify the reason of these changed properties and the working principle of EIReP, HD-PE has been modified by EB treatment in solid and molten state as well as before and after the presence of shear stresses and/or rates of deformation. Shear stresses and/or rates of deformation were applied during injection moulding of tensile specimens. Based on results of previous work the EB treatments and EIReP of HD-PE were performed under nitrogen atmosphere in order to reduce oxygen induced side reactions. The process induced morphological and mechanical properties have been investigated using optical light microscopy, transmission electron microscopy as well as thermal analysis and tensile tests. Changes of molecular mass were measured with size exclusion chromatography and confirmed by rheological measurements. The results demonstrate that the morphology and specific tensile properties of HD-PE were only changed by an EB treatment before the influence of shear stresses and/or rates of deformation on EB modified HD-PE during injection moulding. In addition, the state of aggregate during EB treatment has no influence on morphology and tensile properties. Consequently, the EIReP induced effect based on electron induced changes of HD-PE molecular structure and the subsequent influence of shear stresses and/or rates of deformation.

Enhancement of thermal and mechanical properties of high density polyethylene using commercial clays

The properties required for rainwater containers and pipes were discussed. This work aimed at improving the overall properties of high density polyethylene (HDPE) with commercially available clays for rainwater harvesting system. Ten types of clay were respectively incorporated into HDPE matrix via melt extrusion. Morphological, structural, mechanical and thermal characterizations were performed. The findings show that the clay dispersion state was determined by the thermal stability of their organomodifier. Thermally stable organomodifier dimethyl di(hydrogenated tallow) (2M2HT) prevents clay aggregation and contributes to clay intercalation. The incorporation of high-aspect-ratio clays containing a thermal stable organomodifier improved the mechanical properties of HDPE. Increased Young’s modulus and tensile strength were obtained by addition of appropriate clays. The oxidative induction time (OIT) of clay-HDPE blends were dramatically decreased by the presence of organomodifiers and contaminants. Only unmodified clay with a low impurity content showed less reduction in OIT values. Lastly, it was found that the thermal degradation behavior of blends was related to the dispersion state and the impurity content of clays.