High-density Polyethylene Matrix Research Articles

Preparation of an anti-fouling silicone polyacrylate/SiO2/HDPE composite for industrial wastewater pipe

To mitigate clogging during industrial wastewater piping, a low surface energy composite was prepared by incorporating Silicon-containing acrylate polymer (SAP) and hydrophobically modified SiO2 nanoparticles into High-density polyethylene (HDPE) matrix. The morphological structure, thermal behavior, and anti-fouling performance of the composite were studied. The results showed that the prepared composite has both good thermal stability and compatibility. The acrylate polymer and nanoparticles in the composite not only enhance its hydrophobicity but also decrease the associated surface energy, which may reduce pipe clogging potentials. Besides, the anti-fouling performance of the prepared composite is superior to that of the typical commercial pipe materials, e.g., Polyvinyl chloride (PVC), Polypropylene random (PPR), and Acrylonitrile butadiene styrene (ABS), indicated by a dispensing industrial wastewater immersion experiment.

Dynamic behavior of concurrently printed functionally graded closed cell foams

In this work, functionally graded foams (FGFs) of closed cell types are three-dimensionally printed (3DP) concurrently. These closed cell syntactic foams are manufactured by reinforcing 20, 40, and 60 vol% hollow glass microballoons (GMBs) in the high density polyethylene (HDPE) matrix and are investigated for their mechanical buckling and free vibration response. The critical buckling load (Pcr) of the FGFs are evaluated using the Double Tangent Method (DTM), Modified Budiansky Criteria (MBC), and Vibration Correlation Technique (VCT). It is observed that Pcr evaluated by all three methods are in good agreement. Among all FGFs, FGF-2 exhibited higher buckling strength with 22–26% higher than FGF-1 and FGF-3. Under no-load and uniaxial compressive loads, the first three natural frequency of FGFs and their corresponding damping factors are evaluated. At first mode, the natural frequency of FGFs decreases in the pre-buckling zone and started increasing in the post-buckling zone. Damping factor exhibited reverse trend compared to the trend shown by the natural frequencies. Among all FGFs, FGF-2 (20-40-60 GMB gradation) exhibited better natural frequency. Experimental results are compared with a finite element based simulation results.

Development of Composite Material for Wind Turbine Blades

Rapid increases in the prices of conventional turbine blade making materials as well as future sustainability issues is attracting research interest in the development of polymer composites for turbine blade applications. This study examines the suitability of using a novel bamboo fibre and recycled plastics composite developed for wind turbine blade application. Bamboo fibre was extracted from raw bamboo by chemical and mechanical processes. Recycled High Density Polyethylene (HDPE) was collected, cut into pieces, cleaned and combined with extracted bamboo fibre to form the composite. The percentage ratio of fibre content in the ten specimens ranged from 2.5% to 25%. A series of mechanical tests were conducted on the specimens, including tensile test, impact test, water absorption test and sun radiation test. Results established that as the percentage of bamboo fibre in the specimen increased, the tensile strength and impact energy also increased. Water absorption and sun radiation tests conducted on specimen X revealed no meaningful impact its mechanical properties. Hence, the most significant deduction from this study is that the specimen with 25% bamboo fibre and 75% HDPE matrix possesses the quality that qualifies it to be used as a material for wind turbine blade fabrication.

Towards high-performance all-polyethylene materials by a two-step processing strategy using two-roll mill

In this study, we proposed a unique continuous two-step two-roll mill processing method to prepare high-performance self-reinforced polyethylene materials of high-density polyethylene (HDPE)/ultra-high molecular weight polyethylene (UHMWPE). The first step of high temperature melting is to disperse UHMWPE uniformly in HDPE matrix, and the second step of directional extension upon low-temperature is to significantly improve the structural regularity. The special crystal structures containing interlocked shish-kebab formed and the mechanical properties, barrier property, creep resistance of HDPE/UHMWPE were improved dramatically. Moreover, we found that the effective UHMWPE content is 0.02～0.1%, especially when the content was 0.08%, the tensile strength is 98.2 MPa, nearly double than pure HDPE, and the oxygen permeability is only 18.3% of pure HDPE. So, our study suggests an efficient, eco-friendly strategy for the manufacturing of high-performance all-polyethylene materials, which is of significance for extending the application fields of polyethylene.

Interface Modification, Water Absorption Behaviour and Mechanical Properties of Injection Moulded Short Hemp Fiber-Reinforced Thermoplastic Composites.

The effects of maleic anhydride, stearic acid and water absorption on the physical and flexural properties of injection moulded short hemp fiber-reinforced thermoplastic composites were investigated, in order to understand the suitability of these materials for outdoor applications. The water absorption, diffusion mechanisms and kinetics of composites were evaluated by immersing the specimens in distilled water at 23 °C. Flexural fracture surface morphologies were investigated in order to compare the results of flexural tests with qualitative morphological observations. The process of water absorption was found to follow the Fickian mode of diffusion. Flexural properties ( and ) were affected by the water absorption. The addition of maleic anhydride and stearic acid enhanced the resistance to water absorption of composites and resulted in a slight increase of flexural properties of composites based on a high-density polyethylene (HDPE) matrix. The reduction in flexural properties induced by the degradation of matrix-fiber interfacial bonding due to water absorbed was confirmed by scanning electron microscopy analysis.

Enhancing the mechanical performance of surface-modified microcrystalline cellulose reinforced high-density polyethylene composites

The microcrystalline cellulose (MCC) was successfully modified with a poly(ethylene-co-glycidyl methacrylate) copolymer (PEGMA) to be constructed the PEGMA anchored MCC (PEGMA-a-MCC). The chemical modification of the pristine MCC surface was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. And then, the pristine MCC and PEGMA-a-MCC were successfully incorporated into the high-density polyethylene (HDPE) matrix by typical melt-mixing technique. When applied the PEGMA-a-MCC, interfacial adhesion performance between the cellulosic filler and HDPE matrix showed better and stronger than the pristine MCC. From the results of thermal behaviors and mechanical properties of the composites, it was possible to achieve enhanced their mechanical properties without change of thermal characteristics of HDPE matrix.

Influence of processed waste bagasse fibre-stone dust-6063 aluminium alloy particle on the characteristics of hybrid reinforced recycled HDPE composites

ABSTRACT A novel hybrid composite material was developed through the compression moulding technique by adding bagasse fibre, stone-dust and 6063 aluminium alloy (Al-Mg-Si) particles to recycled high-density polyethylene (rHDPE) matrix. The bagasse fibres were treated while the stone-dust and 6063 aluminium alloy (Al-Mg-Si) particles were sieved to particle sizes of ˂75 µm and ˂250 µm, respectively, before blending with the matrix. The work investigates comparatively, the influence of bagasse fibre-stone dust (hybrid-of-2) and bagasse fibre-stone dust-Al-Mg-Si particles (hybrid-of-3) on composite formation systems for reinforced rHDPE composites. The properties of recycled HDPE and rHDPE composites were thoroughly investigated through selected mechanical properties, wear resistance and thermal conductivity tests. The results show that the addition of bagasse fibre-stone dust-Al-Mg-Si alloy particles improves the mechanical, wear and thermal properties of the composites. The ultimate tensile strength was enhanced by 39% having a UTS value of 32 MPa, tensile modulus by 13% with a value of 98 MPa and wear resistance by 53% with a value of 0.8 g. SEM images showed that these reinforcements blended more properly when lower contents were added. This is responsible for the enhancement observed in the mechanical properties of the hybrid-of-3 reinforced composite.

Synthesis and mechanical properties of HDPE based Nano-Clay polymer composites for industrial applications

ABSTRACT Polymer-based composite structures have a unique advantage over other materials, given that the reinforcement has the necessary properties. Natural fibre-based composites are new materials domains that have emerged in engineering applications in the recent past due to the extensive availability of natural fibres that are less expensive, low density, and biodegradable. Several researchers explored natural fibres’ use as reinforcements in various polymer matrices to improve mechanical and tribological properties. In this context, the adoption of bi-directional silk fibres appears to be very beneficial, and minimal research for structural applications is recorded in this regard. In the present analysis, bi-directional silk fibre is used as a reinforcement medium in a plain-woven fabric with High-Density Polyethylene (HDPE) matrix, with a varying Nano-Clay (NC) percentage from 0.1 to 1 % wt. The compression moulding process is used to process test specimens, and these specimens are further studied for the characterisation of Mechanical Properties. The tensile samples are analysed for fracture analysis by using the Scanning Electron Microscopy (SEM).

Influences of dispersion media for chemically modified cellulose nanofibers on rheological and mechanical properties of cellulose nanofiber reinforced high-density polyethylene

Cellulose nanofibers (CNFs) have exceptional mechanical and thermal properties, but the use of these materials to reinforce polyolefins is challenging. In the present study, ethanol, acetone, isopropyl alcohol (IPA) and water were used as dispersion media for alkenyl succinic anhydride-modified CNFs (ACNFs). Masterbatches were prepared from these ACNFs wetted in the various liquids and then melt-compounded with high-density polyethylene (HDPE) using a twin-screw extruder, followed by injection-molding. The morphologies of the resulting HDPE/ACNF composites were characterized using optical and electron microscopy, and the rheological and mechanical properties of these composites were also evaluated. The results showed that the storage and loss moduli as well as the tensile moduli and strength of the composites produced using the organic liquids were higher than those of the composite made using water, owing to the better dispersion of ACNFs in the HDPE matrix in the former. This improved dispersion would be expected to increase the contact area between the ACNFs and the matrix and to enhance the orientation of the HDPE molecules. IPA was found to give the highest tensile modulus and strength among the organic liquids used in this study. The tensile modulus and strength of the composite containing ACNFs produced from IPA were, respectively, four times and two times higher than those of the neat HDPE. IPA is a relatively non-toxic, inexpensive compound, and so could be readily adopted for industrial scale processing.

Experimental and Analytical study on the elastic properties of HDPE/SWCNT nanocomposites

The development of new materials which possesses specific properties for explicit engineering applications has proven to be a key issue in modern researches and manufacturing industries. This is influenced by the necessity of novel and advanced materials in the aerospace, automotive, biomedical and other industries. One possible solution for progressive material development is a combination of two or more materials of different properties which results with a composite material of improved properties compared to the constituent materials. If one face of materials in a composite material is at the nanoscale the subsequent material is said to be nanocomposite. In this work, High-Density Polyethylene (HDPE) was reinforced with Single-walled Carbon Nanotubes (SWCNTs) nanoparticles at different weight fractions to result with HDPE/SWCNTs nanocomposites. The produced HDPE/SWCNTs nanocomposites were processed according to injection and compression mouldings. The experimental approach was then used to investigate the effect of the two processing approaches and the consequences of adding SWCNTs nanoparticles weight fraction on the elastic properties of the HDPE matrix. The results showed that addition of SWCNTs improves the elastic properties of HDPE/SWCNTs nanocomposites in both processing techniques. Furthermore, injection moulding proved to be better processing method of enhancing the elastic properties of the nanocomposites compared to compression moulding. Finally, three analytical models were used for validation and it was found that the approximation model and model of Pan gives acceptable predictions linking to the experimental results compare to the rule of mixture model.

Study on the effect of carbon fiber addition on the properties of rice straw-plastic composites

Short carbon fiber (SCF), rice straw powder, and high-density polyethylene (HDPE) were melted, mixed, and compounded into composites by compression molding. The effects of carbon fiber content on the mechanical properties of rice straw-high density polyethylene composites (RHCs) were studied. The carbon fibers were characterized by a universal capability test machine (UCTM), scanning electron microscope (SEM), DMA dynamic mechanical analyzer, and a Fourier infrared spectrometer. The results showed that the addition of carbon fiber was beneficial to reduce the creep of RHCs. Meanwhile, the carbon fibers were broken after strength testing. The functional group types of rice straw WPC composites did not change, and the skeleton structure of WPC materials was still retained. When the content of carbon fibers was 9%, a large number of carbon fibers were surrounded by the HDPE matrix; the fibers were broken and rarely pulled out. The results showed that good interfacial bonding took place between the carbon fibers and the composites. The maximum tensile strength of the RHC/S9 was 15.15 MPa, which was 20.7% higher than that of default RHC, and the modulus of elasticity was 52.5% higher than that of default RHC. However, due to the large content of carbon fiber, the distribution of the carbon fibers was uneven in the matrix, and the toughness was reduced.

Mechanical Properties, Morphology and Elemental Composition of Composites Produced from Thermoplastic Polymers Filled with Egg Shell

Mechanical Properties, Morphology and Elemental Composition of Composites Produced from Thermoplastic Polymers Filled with Egg Shell

Effect of alkali treatment and coupling agent on thermal and mechanical properties of Opuntia ficus-indica cladodes fibers reinforced HDPE composites

In this work, Opuntia ficus-indica (OFI) fibers were used as natural reinforcement to high-density polyethylene (HDPE) matrix to valorize unexploited Moroccan natural resources in composites applications. Composites specimens were prepared by combining extruder and injection molding processes using various fibers loadings (2.5, 5 and 10 wt%). OFI fibers were alkali treated to clean their surfaces from non-cellulosic compounds, and styrene–(ethylene–butene)–styrene three-block copolymer grafted with maleic anhydride (SEBS-g-MA) is used as coupling agent to graft maleic groups in the surface of matrix. Combined effects of both treatments on thermal and mechanical properties of prepared composites were investigated. Results showed that the alkali treatment proves to be more effective in improving interfacial adhesion between fibers and matrix, which positively influences the hardness and Young’s modulus properties of composites without SEBS-g-MA, while the addition of coupling agent increased composites plasticity and thermal stability owing to the chemical bond formation at fibers–matrix interface.

Mechanical Properties of Bamboo on Virgin and Recycled High-Density Polyethylene Matrix

Natural fiber-reinforced polymer composites are considered to have advantages over synthetic fibers, namely that they are more environmentally friendly but with better mechanical properties. The purpose of this study was to make a pure / recycled HDPE (High-Density Polyethylene) composite with bamboo fiber reinforcement by analyzing the mechanical properties of the composite. The method used in this research is experimental with a quantitative approach. Experiments are carried out by creating or manipulating certain conditions and by providing control over the test specimen. Pure / recycled HDPE plastics and bamboo fibers will be mixed in a machine extrusion molding with a temperature heater (160, 165, 170, 175) ° C. Before fabrication, bamboo fibers are treated with alkaline treatment, namely by immersing 5% NaOH. The ratio of mass fraction between vHDPE/rHDPE and bamboo fiber was 70%: 30%. This study evaluated the mechanical properties of HDPE-bamboo composites using Izod Impact testing with ASTM D 256-05 standards. Tests were carried out to analyze the differences between pure HDPE and recycled HDPE matrices on bamboo fiber reinforced composites. The mechanical test results showed that the impact strength on bamboo composites with recycled HDPE matrix was 2.69 (KJ / m2) while bamboo composites with pure HDPE matrices had an impact strength of 1.6 (KJ / m2). Thus, the mechanical properties measured by impact strength on composites with recycled HDPE matrices were better than composites with pure HDPE matrices. In accordance with the results of research that has been done, recycled HDPE can be used as a matrix composite with mechanical properties that are not too different from composites with pure HDPE matrices. This can be done as a means of utilizing recycled HDPE waste instead of pure HDPE.

Characteristics of recycled HDPE/bamboo fibre composite

Increasing the mechanical properties of recycling can be done by adding natural fibers into composite materials. The focus of this research is to develop a composite using bamboo as a reinforcing material and recycled High Density Polyethylene (HDPE) as a matrix using the extrusion method. This study aims to analyze the mechanical analysis between bamboo fiber-based composites using a pure HDPE matrix and composites using recycled HDPE matrices at a matrix volume fraction: 70%: 30% fiber. Mechanical tests were performed using the tensile testing machine model RAY-RAN Test Equipment M500-50CT with ASTM D 638 standards to evaluate the tensile strength and modulus of the composite. The results showed that the tensile strength and Young’s modulus of bamboo fiber reinforced rHDPE composites were 8.764 MPa and 52.0152 MPa, respectively. While the bamboo composite with a vHDPE matrix has a tensile strength of 9.3312 MPa and a Young Modulus value of 94.8468 MPa. Thus, bamboo fiber reinforced composites with pure HDPE matrix have better mechanical properties than bamboo composites with recycled HDPE matrices. Differences in matrix shape can affect composites resulting from such fibers.

Effect of different shell materials on the mechanical and thermal properties of core-shell structured bamboo-plastic composites

The purpose of the study was to inspect the mechanical and thermal properties of four kinds of core-shell structured bamboo-plastic composites (BPCs). The materials that were used for the fabrication of the BPCs were high density polyethylene (HDPE), bamboo pulp fibers (BPF)/HDPE, nano-CaCO3/HDPE, and white mud (WM)/HDPE. As verified by flexural properties and impact properties, the dispersion of the BPF, nano-CaCO3, and WM in the HDPE matrix was inhomogeneous. The fracture surface of the scanning electron microscope (SEM) images showed that some aggregates existed in the HDPE. Additionally, X-ray diffraction (XRD) was used to corroborate the results. The thermogravimetric analysis (TGA) showed that the samples with the WM/HDPE shell has little effect on the thermal stability. However, the apparent activation energy (Ea) values of the nano-CaCO3/HDPE shell were higher than those of the other samples, which indicated better thermal stability. The thermal stability had no remarkable changes with the addition of the WM and BPF. The differential scanning calorimeter (DSC) curves revealed that the relative crystallinity of the BPCs increased with the addition fillers, which suggested that the fillers can act as nucleating agents.

Thermo-physical and mechanical characteristics of composites based on high-density polyethylene (HDPE) e spent coffee grounds (SCG)

In this study we attempt to obtain ecological composites, produced from high density polyethylene (HDPE) and spent coffee grounds (SCG), 10–30% w/w, through extrusion and injection molding. The influence of the SCG concentration on the mechanical properties, microstructure, thermal and physical stability of the composites was determined. The incorporation of SCG fibers provided an increase of 49% (modulus of elasticity), and 108% (modulus of flexion) in the stiffness of composites. There was also an increase of approximately 13% in the elasticity of composites with 10% w/w SCG. In general, SCG particles up to 20% w/w were homogeneously dispersed in the HDPE matrix, showing good interaction and compatibility, without the need of a compatibilizer. Another important result was the maintenance of the thermal profile of the HDPE matrix with the incorporation of SCG, without causing processing modifications. Overall, the HDPE/SCG-based approach to obtaining natural fiber reinforced composite (NFRC) was promising, enabling the production of green composites using an underutilized resource, without negatively affecting its properties.

Coffee Silverskin as a Multifunctional Waste Filler for High-Density Polyethylene Green Composites

This work aims to describe the coffee silverskin effect as a lignocellulosic waste filler for high-density polyethylene (HDPE) composites development. The main task was to determine various modification effects resulting from the complex chemical composition of coffee silverskin containing compounds with potential antioxidative properties, including caffeine, polyphenols, tannins, or melanoidins. The processing, thermal, physicochemical, and thermomechanical properties of the HDPE-based composites with different filler content (1–20 wt%) were evaluated. Comprehensively realized thermomechanical analysis revealed the filler’s reinforcing effects on the HDPE matrix while defining problems with obtaining adequate adhesion in the interfacial area. At the same time, studies have shown a very beneficial effect of the silverskin addition on the thermal properties of composites, that even the smallest addition allows for a significant increase in the thermooxidative resistance of HDPE composites assessed using the oxidation induction time from 20 min for HDPE up to 140 min for the composites with 20 wt% of the filler. The obtained research results allow classifying the coffee silverskin waste filler, not only as a filler intended for the production of composites with a high degree of filling but also as an additive that significantly changes the properties of polyethylene in the case of using low concentrations. This can have a very beneficial impact on the development of novel wood polymer (WPC) and natural fiber composites (NFC).

Pengaruh Konsentrasi NaOH terhadap Sifat Termal Komposit Eceng Gondok dan Carbon Nanotube (CNT) dalam Matriks HDPE

This study aims to determine the effect of alkali concentration on the thermal properties of HDPE composites with water hyacinth and carbon nanotubes (CNTs). The method used in this study is the experimental method. Composites made of natural fiber filler, the alkali treated water hyacinth. The water hyacinth was also filled was treated in alkali solution at various concentration (0%, 2%, 4%, 6%, and 8%). In addition to using water hyacinth fiber, the carbon nanotube (CNT) in a matrix of high-density polyethylene (HDPE). The composites were made using Rheomix OS machine. Furthermore, thermal testing of composite specimens using machine Thermogravimetric Analysis (TGA) were conducted. The results obtained from testing the thermal properties is the thermal resistance value. Thermal resistance of composites with alkali treatment of 0%, 2%, 4%, 6%, and 8% were 258,9 0C, 259,5 0C, 260,3 0C, 264,0 0C, and 265,9 0C, respectly. Based on these results it can be concluded that the concentration of NaOH improves the thermal resistance of the composite.

High density polyethylene/wood flour composite: Optimization of processing temperature, processing time and coupling agent concentration

Wood plastic composites (WPCs) consisting of high density polyethylene (HDPE) reinforced with high-loading (55 wt%) of wood flour (WF) were fabricated with melt-blending technique. In this compounding method, processing parameters such as different mixing temperatures (of 165, 180 and 195°C), mixing times (of 5, 10 and 15 minutes) and coupling agent contents (of 2 and 4 wt%) were evaluated. Prepared specimens were analyzed with tensile, Izod, shore D, DMTA, short-term creep, DSC, TGA, water absorption and water contact angle characterizations. Results revealed that mixing temperature of 180°C, mixing time of 10 minutes and coupling agent concentration of 4 wt% were found as the best processing conditions. The mentioned conditions provided enhanced dispersion of WF particles within the HDPE matrix, due to optimum viscosity of the polymer melt and effective residence time of compound in the mixer, and beside them efficient interfacial adhesion between WF and polymer matrix.