Addition Of High-density Polyethylene Research Articles

Enhancing hydrocarbon production via ex-situ catalytic co-pyrolysis of biomass and high-density polyethylene: Study of synergistic effect and aromatics selectivity.

We conducted ex-situ catalytic fast co-pyrolysis (co-CFP) of corn stalk (CS) and high-density polyethylene (HDPE) over HZSM-5 catalyst to enhance the production of hydrocarbons. The effect of pyrolysis temperature and CS-to-HDPE mass ratio (CS/HDPE) on the yield of condensable volatile organic products (CVOPs) and the relative content of hydrocarbons were studied. The synergisms between CS and HDPE were determined based on the difference between the experimental and theoretical CVOP and hydrocarbons content. The results showed that the addition of HDPE significantly promotes the production of CVOPs, reaching the maximum value at 750 °C. In the presence of HZSM-5, the CVOP and hydrocarbons production, especially aromatics, were enhanced further, and 650 °C and 700 °C were the preferable pyrolysis temperature for desired products. Benzene, toluene, and xylenes were the predominant aromatics during the CFP process due to the good shape-selectivity of HZSM-5, contributing to the highest selectivity of C5-C11 compounds in C5+ hydrocarbons. CS/HDPE mass ratio of 1:1 was a critical point for enhancing aromatics yield. CS/HDPE<1 was the recommended mass ratio for increasing the relative aromatic hydrocarbons content, which increases as the CS/HDPE mass ratio decreases. Meanwhile, we presented the potential reaction pathways between CS and HDPE to explain the synergistic effects during the co-CFP process.

The Effect of Recycled HDPE Plastic Additions on Concrete Performance

This study examined HDPE (high-density polyethylene) plastic waste as an added material for concrete mixtures. The selection of HDPE was based on its increased strength, hardness, and resistance to high temperatures compared with other plastics. It focused on how HDPE plastic can be used as an additive in concrete to increase its tensile strength and compressive strength. 156 specimens were used to identify the effect of adding different percentages and sizes of HDPE lamellar particles to lower, medium, and higher strength concrete for non-structural applications. HDPE 0.5 mm thick lamellar particles with sizes of 10 × 10 mm, 5 × 20 mm, and 2.5 × 40 mm were added at 2.5%, 5%, 10%, and 20% by weight of cement. The results showed that the medium concrete class (with compressive strength equal to 10 MPa) had the best response to the addition of HDPE. The 5% HDPE addition represented the optimal mix for all concrete types, while the 5 × 20 mm size was best.

Calcination Behaviour of Nsuta Rhodochrosite Ore in the Presence and Absence of End-of-Life High Density Polyethylene

This research investigated the calcination behaviour of the Nsuta Rhodochrosite (MnCO3) in the presence and absence of end-of-life high density polyethylene (HDPE) using a custom-made palm kernel shell fired furnace. Samples of pulverised Nsuta rhodochrosite were heated rapidly for 30, 40, 50 and 60 minutes, coupled with temperature measurements to determine the maximum temperature attained in the fireclay crucible. The procedure at 60 min was repeated using three blends of rhodochrosite samples containing different masses of HDPE (30 g, 40 g and 50 g) and heated for an hour. For gas analyses studies during calcination, cylindrical compacts of rhodochrosite ore in a LECOTM crucible were heated rapidly with and without high density polyethylene (HDPE at C/O ratio = 1.0, 1.5, and 2.0) in a horizontal tube furnace for 600 s at 1150 °C under high purity argon gas and the off gas was continuously analysed for CH4, CO and CO2 using an online infrared gas analyser. The content of H2 in the off gas was detected using a GC3 gas chromatographic analyser equipped with a thermal conductivity detector. The Nsuta rhodochrosite ore was found to consist of a mixture of manganese II carbonate (MnCO3), silica (SiO2), mixed transition metal carbonate of the form Ca(Mn, Mg)(CO3)2 and mixed metal silicate of the form Ca0.6Mg1.94Si2O6. Calcination results indicated visible colour changes (from grey to dark brown), along with significant changes in the mass before and after calcination. In the absence and presence of the polymer, measured temperatures in the crucible ranged from 1001 °C to 1366 °C and 1361 °C to 1369 °C, respectively. Analyses by XRF showed marginal increase in the content of Mn in the calcined ore with HDPE addition. Gas analyses indicate that blending the carbonate with HDPE before heating results in significant decrease in the amount of CO2 emitted.&#x0D; &#x0D; Keywords: Land Tenure Security, Registration, Spatial Data, Attribute Data

Linear low‐density polyethylene/high‐density polyethylene blends: Effect of high‐density polyethylene content on die swell and flow instability

AbstractThis work aimed to evaluate the effect of high‐density polyethylene (HDPE) content and of shear rate on the die swell and flow instability of linear low‐density polyethylene (LLDPE)/HDPE blends. The results showed that the die swell of the LLDPE/HDPE blends increased with the increase in the shear rate. At high shear rates, the increase in the HDPE content led to an increase in the die swell of LLDPE/HDPE blends. The surface morphology analysis of the extrudates by optical and scanning electron microscopy revealed the presence of sharkskin and stick–slip flow instabilities in LLDPE and LLDPE/HDPE blends at the shear rates investigated. These instabilities were attenuated with the addition of HDPE and almost disappeared in the LLDPE/HDPE blend containing 50 wt% of HDPE.

Study on bonding ability of melt-spun polypropylene/polyethylene blend fibers

This article investigates melt spinning of polypropylene (PP) with high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) blend fibers at different compositions, as well as the effects of HDPE and LLDPE on the bonding ability of blend fibers in thermal bonding process at different temperatures have been studied. HDPE and LLDPE were added to PP at 3, 5, 7, and 10 wt% to measure the upper threshold of such blends. While HDPE was added up to 7 wt%, PP/LLDPE blend fibers were only spun up to 3 wt% of LLDPE. Differential scanning calorimetry (DSC) revealed that increasing both HDPE and LLDPE contents lead to higher crystallinity values due to polyethylenes nucleating effect on PP. By adding HDPE and LLDPE, the tensile strength of blend fibers before and after bonding was decreased drastically compared to pure PP fibers. On the other hand, the addition of HDPE to PP and increasing bonding temperature enhanced bonding strength.

Blended waste utilization in road construction: physical characteristics of bitumen modified with waste cooking oil and high-density polyethylene

The use of bio-oils in the production of asphalt binders has found application mostly in cold climates, and not in hot climates due to the rutting problems associated with bio-oil modified binders. The reality of a harsh and changing climate faced by today’s world necessitates an enhancement of the temperature susceptibility of these binders. This is the focus of this research. In this research, high-density polyethylene (HDPE) is combined with waste cooking oil (WCO) to develop an asphalt binder with improved properties. The results obtained showed that when 7.5% HDPE was added to the binder with 15% replacement of the base bitumen with WCO (B85-WCO15), a 54.7% increase in softening point and 9.3% decrease in penetration were obtained. It was found that higher percentages of WCO can be used for bitumen modification if HDPE is used as a stabilizer. The increased specific gravity obtained from the addition of HDPE provides further evidence that HDPE can be used to stabilize WCO modified binder. The penetration index values indicate that HDPE can be used to reduce the temperature susceptibility of the bio-oil modified binder. The results obtained from this research suggest that waste oils and waste HDPE can be blended in asphalt mixes to deliver asphalt pavements with improved performance.

Recycling of Polypropylene/Polyethylene Blends: Effect of Chain Structure on the Crystallization Behaviors.

The combination of high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polypropylene (PP) is frequently found in polymer waste streams. Because of their similar density, they cannot be easily separated from each other in the recycling stream. Blending of PP/ polyethylenes (PEs) in different ratios possibly eliminate the sorting process used in the regular recycling process. PP has fascinating properties such as excellent processability and chemical resistance. However, insufficient flexibility limits its use for specific applications. Blending of PP with relative flexible PEs might improve its flexibility. This is a unique approach for recycling or upcycling, which aims to maintain or improve the properties of recycled materials. The effects of the branched-chain structures of PEs on the crystallization behavior and the related mechanical properties of such blends were investigated. The overall kinetics of crystallization of PP was significantly influenced by the presence of PEs with different branched-chain structures. The presence of LDPE was found to decrease the overall crystallization rate while the addition of HDPE accelerated the crystallization process of the blends. No negative effect on the mechanical performance and the related crystallinity was observed within the studied parameter range.

Effect of co-feeding HDPE on the product distribution in the hydrocracking of VGO

Abstract The hydrocracking of high-density polyethylene (HDPE) mixed with vacuum gasoil (VGO) (20 wt% HDPE) has been investigated with the aim of assessing this valorization strategy to obtain products suitable to be used as commercial fuel blending streams. The runs have been conducted in a batch reactor at: 400–440 °C; 80 bar; catalyst to feed ratio, 10 gcat gfeed−1; and reaction time, 2 h. Using three different catalysts, PtPd/Y, NiW/Y and NiMo/SA, the effect of the temperature and the composition of the products have been analyzed, comparing obtained results in the hydrocracking of VGO with those obtained for the HDPE/VGO blend. The products distribution has been quantified determining the yields of different lumps, defined according to their boiling point range: gas, naphtha, light cycle oil, heavy cycle oil and coke. The concentration of the families of compounds has been also determined: paraffins, olefins, naphthenes and aromatics (mono-, di- and poly-). Obtained results reveal that the addition of HDPE to the VGO is a promising way to valorize the HDPE, improving the conversion of VGO while producing interesting valuable products. Indeed, at 440 °C and with PtPd/Y catalyst total conversion of HDPE has been obtained, with a naphtha yield of 31.8 wt%.

Improve the Marshall stability of porous asphalt pavement with HDPE addition

Porous asphalt is a gap graded pavement that is 20% air voids which enables rainwater that falls on the road surface to flow through the pavement and into drainage on the side of the road. Porous asphalt has a high shear resistance and dries quickly but its stability is low, it is costly to maintain and needs replacing after only a short time. Despite these disadvantages, porous asphalt is still a good choice in area that experiences heavy annual rainfall. High Density Polyethylene (HDPE), an opaque plastic, is harder and stronger than porous asphalt with a tensile strength of 3100-5500 psi. It is resistant to high temperatures. This study aims to investigate the effect of various percentages of HDPE as an additive to produce an HDPE Asphalt Binder for porous asphalt pavement. Marshall parameters were determined based on the AAPA 2004 standard. It was found that 4% HDPE achieved a maximum stability value of 870 kg at the optimum asphalt content for porous asphalt pavement was 5.54%. Stability of porous asphalt pavement with optimum asphalt content value was 61.1% higher after the addition of HDPE. Thus, the use of HDPE as an additive in Asphalt Binder was able to increase the binding strength of the asphalt minimising the disadvantages of the low stability of traditional porous asphalt pavement.

Improving the Quality of Pyrolysis Oil from Co-firing High-density Polyethylene Plastic Waste and Palm Empty Fruit Bunches

This study aimed to produce and improve the quality of pyrolysis oil as a source of bioenergy that is made by mixing palm empty fruit bunch (EFB) with high-density polyethylene (HDPE) plastic waste. The slow co-pyrolysis method was employed, and HDPE waste and EFB were fed into the pyrolysis reactor at HDPE amounts of 0, 10, 25, 50, 75, and 100% by weight. The pyrolysis oil product was obtained by co-firing EFB with HDPE using the slow co-pyrolysis method in a fixed bed reactor at 500°C with a flow rate of 750 mL/min and a heating rate of 5°C/min. The chemical compositions of pyrolysis oil were analyzed by gas chromatography-mass spectroscopy. A pyrolysis oil produced by HDPE 100 wt.% was dominated by the chemical compounds of phenols, aromatics, aliphatic, and acids, while for EFB 100 wt.% was dominated with aldehydes, acids, phenols, furan and aliphatic. The addition of HDPE reduced the amount of pyrolysis oil yield, increased the pH, reduced the viscosity, and reduced the oxygen content of the pyrolysis oil. These results proved that the HDPE affected the decrease in pyrolysis oil and the increase in gas production from co-firing HDPE and EFB using the slow co-pyrolysis method.

Supercritical CO2 foaming of radiation crosslinked polypropylene/high-density polyethylene blend: Cell structure and tensile property

A blend of isotactic polypropylene (PP) with high-density polyethylene (HDPE) in different PP/HDPE ratios was irradiated by γ-ray to induce cross-linking and then foamed using supercritical carbon dioxide (scCO2) as a blowing agent. Radiation effect on the melting point and crystallinity were analyzed in detail. The average cell diameter and cell density were compared for PP/HDPE foams prepared under different conditions. The optimum absorbed dose for the scCO2 foaming of PP/HDPE in terms of foaming ability and cell structure was 20kGy. Tensile measurements showed that the elongation at break and tensile strength at break of the crosslinked PP/HDPE foams were higher than the non-crosslinked ones. Of particular interest was the increase in the foaming temperature window from 4℃ for pristine PP to 8–12℃ for the radiation crosslinked PP/HDPE blends. This implies much easier handling of scCO2 foaming of crosslinked PP with the addition of HDPE.

Study on the co-pyrolysis of rice straw and high density polyethylene blends using TG-FTIR-MS

The effects of interactions between RS and HDPE on the evolution of volatile species and their distributions during co-pyrolysis of rice straw (RS) and high density polyethylene (HDPE) was investigated by thermogravimetric analyzer coupled with fourier transform infrared spectroscopy and mass spectrometry technology (TG-FTIR-MS). It can be found that the pyrolysis process of RS and HDPE blends was characterized by two stages. The first stage primarily consisted of the decomposition of RS. The second stage was dominant by the degradation of HDPE. The interactions between RS and HDPE were obvious in the temperature range of 435–520°C. The existence of HDPE delayed the decomposition of RS in the first step, while in the second step, the existence of RS delayed the degradation of HDPE. The primary gaseous products for the blends arose from the overlap of the decomposition products from the individual RS and HDPE. However, no new substance can be observed in the blends compared to the decomposition of individual RS and HDPE. The primary gaseous products were H2, H2O, CO2, CO, aldehydes (C2H4O), alcohols (C2H5OH), carboxyls (CH3COOH) and hydrocarbons (CH4, C2H2, C2H4, C2H6, C3H6, C3H8). The addition of HDPE in the blends could decrease the amount of the oxygen-containing compounds, and improve the yield of H2 and hydrocarbons. The effects of the interaction between RS and HDPE on the evolving of volatile species were affected by the percentage of RS in the blends.

Effects of high-density polyethylene and crumb rubber powder as modifiers on properties of hot mix asphalt

The effects of high-density polyethylene (HDPE) and crumb rubber powder (CRP) on the properties of hot mix asphalt were investigated. The physical properties, penetration, softening points, and ductility of unmodified and modified asphalt were measured for various HDPE and CRP contents. Marshall stability and flow, Marshall quotient, moisture sensitivity, and wheel tracking (rutting) tests were also conducted. The results showed that using HDPE and CRP as modifiers improves the physical properties of asphalt and Marshall properties of HMA mixtures. The resistance to moisture damage increased significantly after the addition of HDPE and CRP, as did the resistance to permanent deformation.

Optimization of scratch resistance and mechanical properties in wollastonite-reinforced polypropylene copolymers

The aim of this research was to establish a balance between scratch resistance and scratch damage visibility in the wollastonite-filled heterophasic polypropylene copolymers.The influences of various factors including the surface hardness, elasticity, friction coefficient, and combinations thereof on the scratch behavior (scratch resistance and scratch visibility) were elucidated. Using micro-scale and nano-scale scratch tests and image analysis techniques, the scratch hardness, scratch depth, and scratch visibility of the composites were characterized.It was found that the introduction of wollastonite in the polypropylene copolymer matrix contributes to ductile fracture behavior because of an induced crystallization alteration. Accordingly, the scratch resistance of reinforced composites revealed an increase as a result of higher stiffness of the wollastonite as well as contribution of new crystalline structure. The addition of siloxane to the composites improved the resistance to surface damage by lowering the surface friction coefficient originated from enhanced chain mobility. Simultaneous addition of high density polyethylene and siloxane induced a significant influence on the resistance to the scratch damage. Copyright © 2015 John Wiley & Sons, Ltd.

Preparation and properties of oriented sorghum-thermoplastic composites using flat hot-pressing technology

In order to increase the value of sorghum for bioethanol products, a new method of fabricating oriented sorghum fiber and high-density polyethylene composites (OFPC) using flat hot-pressing technology is presented in this study. The effect of high-density polyethylene (HDPE) loading (0, 10, 20, 30, 40 wt %) on the physical and mechanical properties of OFPC was analyzed. In addition, the mat compression properties, vertical density profile, and microscopic structure of the resulting OFPC were examined. Improvement in mechanical and physical properties of OFPC was observed when 10% HDPE was included with sorghum fiber in the composites. HDPE loading greater than 10% did not further enhance the mechanical properties of OFPC, but improved their water resistance ability. Lower consolidation pressure was required to condense the composite mats with higher HDPE loadings during the hot pressing process. The density distribution of OFPC was greatly improved by the addition of HDPE, but larger density fluctuation was observed at higher HDPE loading.

Morphology and Properties of Polypropylene Foaming Sheet with Alternating Multilayered Structure

In this work, the foaming sheet was designed as alternating multilayered foam/film structure of foaming layers and film layers. The foaming layer contained polypropylene (PP)/high density polyethylene (HDPE)/Talc ternary composites. The film layer contained PP only. The rheological data showed that the melt elasticity of PP was obviously improved by the addition of HDPE and talc. The results exhibited that the alternating multilayered structure was well kept and hardly influenced by the foaming layers, and then the mechanical properties were obviously improved. The cell in the alternating multilayered sheet with 16 layers was smaller and more homogenous than that in pure PP foaming sheet.

Toughening with little rigidity loss and mechanism for modified polypropylene by polymer particles with core–shell structure

Toughening with little rigidity loss was achieved by adding high density polyethylene (HDPE) into polypropylene/ethylene-propylene random copolymer (PP/EPR) blends to fabricate a series of PP/EPR/HDPE ternary blends with core–shell dispersed particles. Morphology observations revealed that the addition of HDPE leads to the appearance of core–shell dispersed particles in PP matrix, i.e., HDPE core encapsulated in EPR shell. Dynamic mechanical analysis results showed that the introduction of HDPE could increase glass transition temperature (Tg) and loss factor peak area of EPR in PP/EPR/HDPE blends, which is similar to the effect of adding EPR in PP/EPR. The shrinkage behavior results suggested that the increase of glass transition temperature of EPR was induced by the mismatch of thermal expansion coefficients of components and the larger peak area was ascribed to the stronger relaxation friction of EPR. According to percolation of stress volumes, the interparticle distance was proposed to be a key factor of toughening effect of rubber particles in thermoplastic and thereby a toughening mechanism about the equivalent rubber content was established to explain balanced toughness-strength improvement of PP/EPR/HDPE blends with core–shell particles. The rubber particles with core–shell structure lead to the increase of particle size and the decrease of interparticle distance on the premise of not increasing actual rubber content, resulting in a notable improvement of toughness, while the ‘hard’ core made from HDPE component provides a satisfied rigidity.

PENGARUH PENGGUNAAN SERAT HIGH DENSITY POLYETHYLENE (HDPE) PADA CAMPURAN BETON TERHADAP KUAT TARIK BETON

PENGARUH PENGGUNAAN SERAT HIGH DENSITYPOLYETHYLENE (HDPE) PADA CAMPURAN BETON TERHADAPKUAT TARIK BETON1)Erwin Rommel, 2)Yunan Rusdianto, 3)Anita Kurniati1,2,3)Jurusan Teknik Sipil Fakultas Teknik Universitas Muhammadiyah Malang3)Alumni Teknik Sipil FT-UMMemail : erwin67pro@yahoo.comABSTRACTResearch on the addition of HDPE fibers in normal concrete is intended to determine therelationship between the percentage of variation of fiber addition of HDPE to the workability, tensilestrength and determine the pattern of deployment of fiber in concrete. The addition of HDPE fibersis intended to increase the tensile strength of concrete.The concrete was mixed using gresik cement type PPC, sand with the gradation limits zone 2,the gravel with a maximum grain size of 20 mm, and HDPE fibers with a width of 0.5 cm and 2.5cm long. Variations in the addition of HDPE fibers are 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%,9%, 10% of the volume of the mixture. Tensile strength testing performed with a cylindrical testpiece with a diameter of 150 mm and 300 mm height at the age of 28 days of the test object. Tensilestrength of concrete data analysis using regression analysis.The results showed that the addition of HDPE fibers can increase the value of tensile strengthsides. There is a strong pull on the sides of the optimum levels of 4% with a tensile strength of 2.86MPa increased by 18%Key words: Concrete, HDPE fibers, Tensile strength

Textural changes in metallurgical coke prepared with polyethylene

The effect of high-density polyethylene (HDPE) on the textural features of experimental coke was investigated using polarized-light optical microscopy and wavelet-based image analysis. Metallurgical coke samples were prepared in a laboratory-scale furnace with 2.5%, 5.0%, 7.5%, 10.0%, and 12.5% HDPE by mass, and one sample was prepared by 100% coal. The amounts and distribution of textures (isotropic, mosaic and banded) and pores were obtained. The calculations reveal that the addition of HDPE results in a decrease of mosaic texture and an increase of isotropic texture. Ethylene formed from the decomposition of HDPE is considered as a probable reason for the texture modifications. The approach used in this study can be applied to indirect evaluation for the reactivity and strength of coke.

Stress–Strain and Diffusion Behavior of Industrial Waste-filled Acrylonitrile–Butadiene Rubber/High Density Polyethylene Blends

Abstract The mechanical properties and diffusion behavior of marble waste (MW)-filled acrylonitrile–butadiene rubber (NBR)/high density polyethylene (HDPE) blends were studied as a function of blend composition. A sulfur curing system was employed to crosslink the thermoplastic elastomer (TPE) blends. The results obtained showed that the physical properties of vulcanized NBR/HDPE blends were enhanced with the addition of HDPE in MW-filled vulcanized NBR/HDPE blends. Mechanical properties such as stress–strain behavior, tensile strength, modulus, and % elongation at break and tear strength, were assessed and found to fluctuate with the blend ratio. HDPE-incorporated vulcanized NBR/HDPE blends have been found to reveal a reduced toluene uptake trend compare to the NBR compound.