Foams based on low density polyethylene/hectorite nanocomposites: Thermal stability and thermo-mechanical properties

2007 ◽  
Vol 105 (3) ◽  
pp. 1658-1667 ◽  
Author(s):  
J. I. Velasco ◽  
M. Antunes ◽  
O. Ayyad ◽  
C. Saiz-Arroyo ◽  
M. A. Rodríguez-Pérez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Low Density Polyethylene ◽  
Low Density

scholarly journals Influence of High-Concentration LLDPE on the Manufacturing Process and Morphology of Pitch/LLDPE Fibres

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1099
Author(s):  
Salem Mohammed Aldosari ◽  
Muhammad A. Khan ◽  
Sameer Rahatekar
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Modulus ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
High Concentration ◽  
Scanning Electron Microscope Study ◽  
High Concentrations ◽  
Thermal Stability Of

A high modulus of elasticity is a distinctive feature of carbon fibres produced from mesophase pitch. In this work, we expand our previous study of pitch/linear low-density polyethylene blend fibres, increasing the concentration of the linear low-density polyethylene in the blend into the range of from 30 to 90 wt%. A scanning electron microscope study showed two distinct phases in the fibres: one linear low-density polyethylene, and the other pitch fibre. Unique morphologies of the blend were observed. They ranged from continuous microfibres of pitch embedded in linear low-density polyethylene (occurring at high concentrations of pitch) to a discontinuous region showing the presence of spherical pitch nodules (at high concentrations of linear low-density polyethylene). The corresponding mechanical properties—such as tensile strength, tensile modulus, and strain at failure—of different concentrations of linear low-density polyethylene in the pitch fibre were measured and are reported here. Thermogravimetric analysis was used to investigate how the increased linear low-density polyethylene content affected the thermal stability of linear low-density polyethylene/pitch fibres. It is shown that selecting appropriate linear low-density polyethylene concentrations is required, depending on the requirement of thermal stability and mechanical properties of the fibres. Our study offers new and useful guidance to the scientific community to help select the appropriate combinations of linear low-density polyethylene/pitch blend concentrations based on the required mechanical property and thermal stability of the fibres.

Thermal and mechanical properties of nanocomposites based on polyethylene and Mg/Al hydrotalcite

2016 ◽  
Vol 1817 ◽  
Author(s):  
L.Y. Jaramillo ◽  
J.C. Posada-Correa ◽  
E. Pabón-Gelves ◽  
E. Ramos-Ramírez ◽  
N.L. Gutiérrez-Ortega
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Properties ◽  
Structural Analysis ◽  
Tensile Tests ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Melt Blending ◽  
Thermal And Mechanical Properties ◽  
Linear Low Density Polyethylene

ABSTRACTIn this work there was studied the effect of nano-Mg/Al hydrotalcite (NHT) as filler on maleic anhydride grafted linear low density polyethylene (LLDPE-g-MA). NHT was synthesized by the coprecipitation method with a ratio of Mg/Al=6 and nanocomposites were prepared using 1, 3 and 5 %wt of filler via melt-blending.Morphological and structural analysis of NHT were performed and for nanocomposites, tensile tests and thermal properties were measured. Results showed that filler was well dispersed in the LLDPE matrix, mechanical properties were enhanced in most of the cases and thermal stability improvements were achieved in the nanocomposites.

Characteristic of low-density polyethylene reinforcement with nano/micro particles of carbon black: a comparative study

2021 ◽  
Vol 2 (110) ◽  
pp. 49-58
Author(s):  
O.H. Sabr ◽  
N.H. Al-Mutairi ◽  
A.Y. Layla
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Black ◽  
Uniform Distribution ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Carbon Black Nanoparticles

Purpose: Low density polyethylene is commonly used polymer in the industry because of its unique structure and excellent overall performance. LDPE, is relatively low mechanical properties and thermal stability can sometimes limit its application in industry. Therefore, the development of particulate reinforced polymer composites is one of the highly promising methodologies in the area of next generation engineering products. Design/methodology/approach: Nano and Micro composite from low density polyethylene LDPE reinforced with different weight fraction of carbon black particles (CB) (2, 4 and 8)% prepared by first dispersion Nano and Micro carbon black particles CB in solvent and then mixing manually with low density polyethylene LDPE pellet and blended by twin-screw extruder, the current research study the mechanical properties (tensile strength, elastic modulus,and hardness), FTIR, DSC,and thermal conductivity of prepared nano and micro composites using two methodes and the morphological properties of nano-micro composites. Findings: The tensile strength of the LDPE/CB nano and micro composites improved at 2% and 4%, respectively, and decreasing at 8%, addition of carbon black nanoparticles led to increase the tensile strength of pure low-density polyethylene from 13.536 MPa to 19.71 MPa, and then dropping to 11.03 MPa at 8% percent,while the elastic modulus of LDPE/ CB nano and miro composites shows an improvement with all percentages of CB. The results show that the mechanical properties were improved by the addition carbon black nanoparticles more than addition micro- carbon black . FTIR show that physical interaction between LDPE and carbon black. The thermal conductivity improvement from 0.33 w/m.k for pur LDPE to 0.62234 w/m.k at 2% CB microparticle content and the reduced to 0.18645 w/m.k and 0.34063 w/m.k at (4 and 8)% micro-CB respectively , The thermal conductivity of LDPE-CB nano-composites is low in general than that the LDPE-CB microcomposite. DSC result show improvement in crystallization temperature Tc, melting temperature and degree of crystallization with addition nano and micro carbon black. Morever, SEM images revealed to uniform distribution and good bonding between LDPE and CB at low percentages and the precence of some agglomeration at high CB content.Research limitations/implications: This research studied the characteristics of both nano and micro composite materials prepared by two steps: mixing CB particles with solvent and then prepared by twin extruder which can be used packaging material, but the main limitation was the uniform distribution of nano and micro CB particles within the LDPE matrix. In a further study, prepare a blend from LDPE with other materials and improve the degradation of the blend that used in packaging application. Originality/value: LDPE with nanocomposites are of great interest because of their thermal stability, increased mechanical strength, stiffness, and low gas permeability, among other properties that have made them ideal for applications in the packaging and automotive industries. LDPE reinforcements nano-sized carbon black can have better mechanical and thermal properties than micron, resulting in less material being needed for a given application at a lower cost.

scholarly journals Effect of different loading low density polyethylene (LDPE) on the thermal and mechanical properties of Tapioca starch-based plastic composite

2020 ◽  
Vol 3 (1) ◽  
pp. 25
Author(s):  
Norin Zamiah Kassim Shaari ◽  
Mazlan Bairik ◽  
Junaidah Jai
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Low Density Polyethylene ◽  
Mechanical And Thermal Properties ◽  
Low Density ◽  
Thermal And Mechanical Properties ◽  
Tapioca Starch ◽  
Plastic Composite ◽  
Internal Mixer

Effect of incorporating different loading of low densities polyethylene (LDPE) on the mechanical and thermal properties of the plastic composite made from tapioca starch was investigated. The compound formulation was done in the internal mixer and the lump produced was crushed. Then, the crushed sample was compressed to form a dumbbell-shaped in a compression molding equipment, heated at 140oC. The sample was subsequently analyzed for tensile property, thermal stability and functional groups. Results show that the incorporation of LDPE improves thermal and mechanical stabilities of the plastic composite. However, too much LDPE causes lower ductility of the composites. LDPE-15 was found as the best formulation since it has moderate tensile strength with good elongation.

Broad studies of graphene and low-density polyethylene composites

2018 ◽  
Vol 51 (6) ◽  
pp. 527-561 ◽  
Author(s):  
Maziyar Sabet ◽  
Hassan Soleimani
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Thermal Stability ◽  
High Specific Surface Area ◽  
Polymer Chains ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Lattice Order ◽  
Relative Crystallinity ◽  
Local Lattice

Graphene (Gr) distribution in low-density polyethylene (LDPE) considerably increased thermal stability, thermal conductivity, mechanical properties, and flexural properties of LDPE/Gr composites. Addition of Grs to LDPE postponed the time for making the polymer brittle. High specific surface area and superior properties of Gr improved thermal stability, conductivity, storage modulus, and mechanical properties of composites. The electrical conductivity of LDPE/Grs composites upgraded owing to the thermal stability of Grs in LDPE matrix. In terms of rheology, the addition of Grs augmented viscosity of the LDPE matrix. Addition of Grs to LDPE nucleates crystallization by reducing the activation energy along with rising crystallization onset temperature. Adding Gr facilitated decreasing aggregation, expanded crystallinity, improved the local lattice order of LDPE/Grs, and advanced Grs contact with LDPE. Thus, on a macroscopic scale, Gr constrains mobility of polymer chains, causing a growth in stiffness and strength of the composite. The distribution of Grs in LDPE at micron size scale was verified by atomic force microscopy and other microscopic testers. With further Grs inclusions to LDPE, the activation energy reduced, Grs proceeded as nucleating agents throughout the crystallization of composites, and increased the enhancement of relative crystallinity of LDPE/Gr compounds. The percolation phenomenon of LDPE/Gr composite occurred about 0.5 wt% of Gr loading. Due to further addition of Gr to LDPE, the impermeability of oxygen through the conduit raised somehow the LDPE/Gr sample with 0.5 wt% Gr content, generated a sharp improvement, and dropped fuel permeation with about 37% in comparison with pure LDPE.

scholarly journals Low-Temperature Mechanical Properties of High-Density and Low-Density Polyethylene and Their Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1821
Author(s):  
Ildar I. Salakhov ◽  
Nadim M. Shaidullin ◽  
Anatoly E. Chalykh ◽  
Mikhail A. Matsko ◽  
Alexey V. Shapagin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Impact Strength ◽  
Relative Elongation ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Elongation At Break ◽  
Subzero Temperatures ◽  
Izod Impact

Low-temperature properties of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and their blends were studied. The analyzed low-temperature mechanical properties involve the deformation resistance and impact strength characteristics. HDPE is a bimodal ethylene/1-hexene copolymer; LDPE is a branched ethylene homopolymer containing short-chain branches of different length; LLDPE is a binary ethylene/1-butene copolymer and an ethylene/1-butene/1-hexene terpolymer. The samples of copolymers and their blends were studied by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), 13С NMR spectroscopy, and dynamic mechanical analysis (DMA) using testing machines equipped with a cryochamber. It is proposed that such parameters as “relative elongation at break at −45 °C” and “Izod impact strength at −40 °C” are used instead of the ductile-to-brittle transition temperature to assess frost resistance properties because these parameters are more sensitive to deformation and impact at subzero temperatures for HDPE. LLDPE is shown to exhibit higher relative elongation at break at −45 °C and Izod impact strength at −20 ÷ 60 °C compared to those of LDPE. LLDPE terpolymer added to HDPE (at a content ≥ 25 wt.%) simultaneously increases flow properties and improves tensile properties of the blend at −45 °C. Changes in low-temperature properties as a function of molecular weight, MWD, crystallinity, and branch content were determined for HDPE, LLDPE, and their blends. The DMA data prove the resulting dependences. The reported findings allow one to understand and predict mechanical properties in the HDPE–LLDPE systems at subzero temperatures.

Preparing and Applying of Flame Retardant Microcapsules Containing Magnesium Hydroxide

2013 ◽  
Vol 734-737 ◽  
pp. 2191-2194
Author(s):  
Li Li Wu ◽  
Yuan Lian ◽  
Dan Liu ◽  
Hua Zheng ◽  
Dian Wu Huang
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Magnesium Hydroxide ◽  
Low Density Polyethylene ◽  
Core Shell ◽  
Low Density ◽  
Melamine Resin ◽  
Shell Material ◽  
Elongation At Break ◽  
Good Thermal Stability

In this study, flame retardant microcapsules were synthesized using magnesium hydroxide as core materials, melamine resin as the shell material. The structure, diameters and thermal properties of prepared microcapsules were investigated by using FTIR, ELS, DSC and TGA. The effects of core/shell ratio on the properties of microcapsules were studied.Flame retardant materials of low-density polyethylene/magnesium hydroxide microcapsules were prepared.The tensile strength and elongation at break tests were performed to determine its mechanical property.Inflammability of the materials was also studied.The results showed the prepared magnesium hydroxide microcapsule shows good thermal stability and it has free compatibility with the polymer.The composites of HDPE/MH microcapsules have good performance．

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