Effect of different morphologies on the creep behavior of high-density polyethylene

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 3470-3479 ◽  
Author(s):  
Yuxi Pan ◽  
Xueqin Gao ◽  
Jun Lei ◽  
ZhongMing Li ◽  
KaiZhi Shen
Keyword(s):  
Creep Behavior ◽  
High Density Polyethylene ◽  
Polymeric Materials ◽  
High Density ◽  
Polymer Materials

With the wide use of polymer materials as pressure parts, people have started paying more attention to the safety and longevity of polymeric materials.

scholarly journals Corrosion Inhibition Efficiencies of Polymeric Materials on Alloy Steel in Dilute Hydrochloric Acid and Sodium Hydroxide Solutions at Ambient Temperature

2020 ◽  
Vol 7 (2) ◽  
pp. C27-C32
Author(s):  
I.E. Ekengwu ◽  
O.G. Utu ◽  
K.O. Anyanwu
Keyword(s):  
Corrosion Rate ◽  
Ambient Temperature ◽  
Alloy Steel ◽  
Corrosion Inhibition ◽  
High Density Polyethylene ◽  
Inhibition Efficiency ◽  
Polymeric Materials ◽  
High Density ◽  
Alkaline Solutions ◽  
Ph Values

A corrosion control test was conducted on alloy steel, using polymeric coatings (polyurethane, bitumen (medium airing), and high-density polyethylene) in dilute HCl solutions of pH values 4, 7, and 12, respectively for acid, neutral and alkaline solutions at ambient temperature. In the study, Eighty-four coupons of alloy steel were used. The coupons were mechanized, ground, polished, etched with natal, and weighed using a digital weighing balance (Beva 206B). The mass of each coupon was recorded according to the tag number on them. Twenty-one of the coupons were coated with polyurethane, 21 coated with medium curing bitumen (MC), and 21 coated with high-density polyethylene, while 21 were left uncoated. Seven polyurethane-coated samples, bitumen coating, and uncoated coupons were suspended in dilute HCl solutions of pH values 4, 7, and 12. Every week, one sample is taken from each of the solutions, the coatings and the corrosion products were removed, and the coupons were etched with natal. Then the coupons were reweighed, and their masses were recorded in accordance with their tag number. The weight loss per unit area of the coupons, corrosion rate, and percentage corrosion inhibition efficiencies of the coatings was calculated over seven weeks. The results obtained were tabulated and represented graphically. From the results obtained, it is seen that the corrosion inhibition efficiency of polyurethane coatings is higher compared with bitumen and polyethylene. It is also seen from the graphs that the corrosion rate of the coupons is higher in acid, a little bit lower in alkaline, and much lower in neutral solution. It is also observed that the corrosion rates fall with time as the inhibition efficiency also falls with time.

Electrical and dielectric sensitivities to thermal processes in carbon nanofiber/high-density polyethylene composites

2011 ◽  
Vol 18 (1-2) ◽  
pp. 51-60 ◽  
Author(s):  
Tian Liu ◽  
Weston Wood ◽  
Bin Li ◽  
Brooks Lively ◽  
Wei-Hong Zhong
Keyword(s):  
Dielectric Properties ◽  
Thermal Treatment ◽  
High Density Polyethylene ◽  
Ac Conductivity ◽  
Elevated Temperatures ◽  
Carbon Nanofiber ◽  
Polymeric Materials ◽  
High Density ◽  
Heating Process ◽  
Thermal Processes

AbstractOwing to the huge interface region existing in a polymer nanocomposite, the effects of thermal processes on properties of nanocomposites are much more complicated than in a pure polymer. It is therefore important to determine the effects of thermal processes on nanocomposites with different interfacial interactions between the nanofillers and the polymer matrix. It is also important to explore the performance changes for nanocomposites under elevated temperatures over pure polymers. In this investigation, we examined the correlation of thermal treatment with dielectric properties of carbon nanofiber (CNF) reinforced high-density polyethylene nanocomposites. The thermal treatment of specimens was conducted for up to 120 h at 87°C and 127°C. Then, alternating current (AC) conductivity and dielectric properties were tested after definite intervals of time. Their changing rates over treatment time were analyzed. The results revealed the approximate linear relationships of AC conductivity and dielectric constant vs. heating time. Modified CNF reinforced nanocomposites had less influence by the heating treatments exhibiting better thermal resistance. The change rates of AC conductivity σ and dielectric properties have higher sensitivity to the treatment at a higher temperature. This study provides potential for further research on application of electrical and dielectric signals to detect the effects of heating process on lifetime of polymeric materials.

Reinforcing Effect of Montmorillonite Nanoclay on Mechanical Properties of High Density Polyethylene Nanocomposites

2014 ◽  
Vol 591 ◽  
pp. 60-63 ◽  
Author(s):  
N. Venkatesan ◽  
G.B. Bhaskar ◽  
Kaliyaperumal Pazhanivel ◽  
K. Poyyathappan
Keyword(s):  
Mechanical Properties ◽  
High Density Polyethylene ◽  
Solid Material ◽  
High Density ◽  
Polymer Materials ◽  
Good Surface ◽  
Melt Compounding ◽  
Standard Specimens ◽  
Twin Screw ◽  
Good Surface Finish

In recent years, many researches focused on the polymer materials to study the characteristics and to enhance the mechanical properties of the nanocomposites in order to understand the factors which lead to the desired dispersion of nanoclay in the polymer matrix. The samples used in this work were prepared through melt compounding, using high-density polyethylene and organo-modified clay of montmorillonite (MMT). During manufacturing of MMT/HDPE nanocomposites, a silane modifier and polyethylene grafted with maleic anhydride (compatibilizer) were added to get good surface finish and to act as bonding agent respectively. In addition, the compatibilizer will help in attaining better intercalation. Using a Plastograph-Mixer through twin-screw extruder, the high density polyethylene and different weight percentages (0, 1, 2, 3, 4 wt. %) of MMT are mixed and subsequently the composite is produced in the form of solid material. ASTM standard specimens for various tests are produced using injection molding machine with respective dies. The prepared experimental specimens for various tests like tensile, flexural, impact and shore-hardness are tested for its respective strengths. From this investigation, it is concluded that the addition of MMT nanoclay in HDPE has significantly influenced the mechanical properties of the composites.

Nanocomposite Polymeric Materials Based on Butyl Rhodamine B Incorporated in Mesoporous Films of High-Density Polyethylene

2020 ◽  
Vol 90 (4) ◽  
pp. 737-742
Author(s):  
O. V. Arzhakova ◽  
A. A. Dolgova ◽  
A. Yu. Kopnov ◽  
A. I. Nazarov ◽  
A. Yu. Yarysheva ◽  
...  
Keyword(s):  
Rhodamine B ◽  
High Density Polyethylene ◽  
Polymeric Materials ◽  
High Density ◽  
Mesoporous Films ◽  
Butyl Rhodamine B

scholarly journals Flexural Creep Behavior of High-Density Polyethylene Lumber and Wood Plastic Composite Lumber Made from Thermally Modified Wood

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 262 ◽  
Author(s):  
Murtada Abass A. Alrubaie ◽  
Roberto A. Lopez-Anido ◽  
Douglas J. Gardner
Keyword(s):  
Creep Behavior ◽  
Creep Deformation ◽  
High Density Polyethylene ◽  
Creep Compliance ◽  
High Density ◽  
Wood Plastic Composite ◽  
Creep Stress ◽  
Plastic Composite ◽  
Thermally Modified Wood ◽  
Modified Wood

The use of wood plastic composite lumber as a structural member material in marine applications is challenging due to the tendency of wood plastic composites (WPCs) to creep and absorb water. A novel patent-pending WPC formulation that combines a thermally modified wood flour (as a cellulosic material) and a high strength styrenic copolymer (high impact polystyrene and styrene maleic anhydride) have been developed with advantageous viscoelastic properties (low initial creep compliance and creep rate) compared with the conventional WPCs. In this study, the creep behavior of the WPC and high-density polyethylene (HDPE) lumber in flexure was characterized and compared. Three sample groupings of WPC and HDPE lumber were subjected to three levels of creep stress; 7.5, 15, and 30% of the ultimate flexural strength (Fb) for a duration of 180 days. Because of the relatively low initial creep compliance of the WPC specimens (five times less) compared with the initial creep compliance of HDPE specimens, the creep deformation of HDPE specimens was six times higher than the creep deformation of WPC specimens at the 30% creep stress level. A Power Law model predicted that the strain (3%) to failure in the HDPE lumber would occur in 1.5 years at 30% Fb flexural stress while the predicted strain (1%) failure for the WPC lumber would occur in 150 years. The findings of this study suggest using the WPC lumber in structural application to replace the HDPE lumber in flexure attributable to the low time-dependent deformation when the applied stress value is withing the linear region of the stress-strain relationship.

Study on the solidification kinetics of high-density polyethylene during thin-walled injection molding process

2012 ◽  
Vol 32 (6-7) ◽  
pp. 355-363 ◽  
Author(s):  
Shuang-quan Deng ◽  
Bin Yang ◽  
Ji-bin Miao ◽  
Ru Xia ◽  
Jia-sheng Qian ◽  
...  
Keyword(s):  
Injection Molding ◽  
High Density Polyethylene ◽  
Polymeric Materials ◽  
High Density ◽  
Injection Molding Process ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Molding Process ◽  
Solidification Kinetics ◽  
Thin Walled

Abstract In this work, the effect of the initial and secondary temperature differences on the solidification behaviors of high-density polyethylene (HDPE) during the thin-walled injection molding (TWIM) was intensively investigated. Simulated temperature profiles using the enthalpy transformation methodology were compared with an in situ temperature measurement, and reasonable agreement was achieved between calculations and measurements. Two-dimensional wide-angle X-ray diffraction characterization shows that the formation of oriented crystal structures was considerably affected by the thermal gradient within the injection-molded article. The present study can be practically significant to the optimization of the cooling parameters during the TWIM of crystalline polymers as well as to the further study on the relationship among “processing-structure-property” of polymeric materials.

Hyperelastic Analysis of High Density Polyethylene under Monotonic Compressive Load

2012 ◽  
Vol 229-231 ◽  
pp. 309-313 ◽  
Author(s):  
M. Khalajmasoumi ◽  
S.S.R. Koloor ◽  
A. Arefnia ◽  
I.S. Ibrahim ◽  
J. Mohd Yatim
Keyword(s):  
High Density Polyethylene ◽  
Compressive Load ◽  
Weight Ratio ◽  
High Density ◽  
Polymer Materials ◽  
Experimental Result ◽  
Nonlinear Behaviour ◽  
Compression Tests ◽  
Design Development ◽  
Simulation Procedure

In the past few decades, design development of high performance machines and devices encouraged industries to utilize advanced materials such as polymers. Special mechanical features of polymer materials such as high strength to weight ratio and etc have increased scientists demands to investigate the nonlinear behaviour of polymers. One of the challenges in mechanic of polymers is to introducing a model that is competent to predict hyperelastic deformations based on long-strain behaviour of polymers. In this study, a comprehensive research is performed on introduced mechanical models for polymer materials. The major attempt was on introducing an appropriate model among the existing models, capable enough to predict mechanical behaviour of high density polyethylene under monotonic compressive load. The procedures of simulation and experimental tests are performed to examine the load capability of the model for high density polyethylene. Several compression tests are performed on High Density Polyethylene cubic specimens to extract the full stress-strain response of the high density polyethylene. Moreover, strain gauge is used in experimental tensile test to determine Poisson’s ratio. Simulation procedure is performed using ABAQUS 6.9EF for a comprehensive analysis and discussion on hyperelastic deformation. The simulation procedure is confirmed and verified perfectly by experimental data. The comparison between experimental result of compression test under monotonic load and finite element simulation of this test is remarkable to know about behaviour of HDPE to use in other structural and mechanical application.

scholarly journals Investigation of Tensile Creep Behavior for High-Density Polyethylene (HDPE) via Experiments and Mathematical Model

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6188
Author(s):  
Qiang Mao ◽  
Buyun Su ◽  
Ruiqiang Ma ◽  
Zhiqiang Li
Keyword(s):  
Creep Behavior ◽  
High Density Polyethylene ◽  
Strain Curve ◽  
Reference Value ◽  
High Density ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
Form Model ◽  
Short Time ◽  
Parameter Values

Temperatures of −25 °C, +5 °C, and +35 °C were selected to study the creep behavior of high-density polyethylene (HDPE). The ultimate tensile strength of HDPE materials was obtained through uniaxial tensile experiments and the time–strain curves were obtained through creep experiments. When the loaded stress levels were lower than 60% of the ultimate strength, the specimens could maintain a longer time in the stable creep stage and were not prone to necking. In contrast, the specimens necked in a short time. Then, the time hardening form model was applied to simulate the time–strain curve and the parameter values were solved. The parameter values changed exponentially with the stresses, thereby expanding and transforming the time hardening model. The expanded model can easily and accurately predict creep behaviors of the initial and stable creep stages as well as the long-term deformations of HDPE materials. This study would provide a theoretical basis and reference value for engineering applications of HDPE.

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