scholarly journals Effect of Graphene Nanoplatelets on the Structure, the Morphology, and the Dielectric Behavior of Low-Density Polyethylene Nanocomposites

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4776 ◽  
Author(s):  
Athena Maniadi ◽  
Maria Vamvakaki ◽  
Mirela Suchea ◽  
Ioan Valentin Tudose ◽  
Marian Popescu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Polymer Matrix ◽  
Dielectric Behavior ◽  
Graphene Nanoplatelets ◽  
Low Density Polyethylene ◽  
Dielectric Losses ◽  
Low Density ◽  
Air Gaps ◽  
Structural And Electrical Properties ◽  
Matrix Properties

The incorporation of graphene nanoplatelets (GnPs) within a polymer matrix can play an important role in the physical properties and the functionality of the composite material. Composites consisting of low-density polyethylene (LDPE) and GnPs of different concentrations were developed by mixing GnPs with a molten form of the polymeric matrix. The effect of the GnPs content on the morphological, structural, and electrical properties of the composites were investigated. As shown, graphene presence and its concentration significantly modified the polymer matrix properties, a behavior that can be employed for tailoring its applicability in electrical applications. It was found that the increase of the graphene platelets concentration seems to promote the formation of graphene agglomerates, air gaps, and inhomogeneities, while higher dielectric constant/lower dielectric losses can be achieved.

scholarly journals Low-Density Polyethylene Films Carrying ferula asafoetida Extract for Active Food Packaging: Thermal, Mechanical, Optical, Barrier, and Antifungal Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Razieh Niazmand ◽  
Bibi Marzieh Razavizadeh ◽  
Farzaneh Sabbagh
Keyword(s):  
Polymer Matrix ◽  
Food Packaging ◽  
Barrier Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Optical Barrier ◽  
Leaf Extracts ◽  
Polyethylene Films ◽  
Active Food Packaging ◽  
Ferula Asafoetida

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.

scholarly journals Fabrication and Characterization of Jute Fiber Reinforced Low Density Polyethylene Based Composites: Effects of Chemical Treatment

2011 ◽  
Vol 3 (2) ◽  
pp. 249-259 ◽  
Author(s):  
M. J. Miah ◽  
M. A. Khan ◽  
R. A. Khan
Keyword(s):  
Mechanical Properties ◽  
Dielectric Constant ◽  
Tensile Strength ◽  
Loss Tangent ◽  
Chemical Treatment ◽  
Bending Strength ◽  
Jute Fiber ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Jute Fibers

Jute fiber reinforced low density polyethylene (LDPE) composites (10-30% fiber, by weight) are prepared by compression molding. Tensile strength (TS), bending strength (BS) and bending elongation (BE) of the composites are increased over LDPE.  Jute fiber is treated with monomer (2-hydroxyethyl methacrylate, HEMA) along with two different initiators in methanol solvent. Jute fibers are soaked with 10% HEMA+2% Irgacure-184 (F1-Formulation) and 3% HEMA+2% benzol peroxide (F2-Formulation) and dried at 80ºC for 2 hours then composites are fabricated by compression molding. It is found that due to chemical treatment of the jute fibers, a significant improvement of the mechanical properties of the composites are happened (56% TS, 30% BS and 35% BE) compared to the LDPE. 3%HEMA+2% benzol peroxide treated jute composites found better mechanical properties compared to 10%HEMA+2% Irgacure-184 treated jute composites. Dielectric constant and loss tangent of the composites are increased with increasing temperature up to a transition temperature and then decreased, finally reached to plateau. Scanning Electron Microscopic (SEM) analysis of the fracture side of the composites are carried out and supported better fiber-matrix adhesion due to the chemical treatment.Keywords: Jute fiber; Polyethylene; Composite; Tensile strength; Bending strength; Dielectric constant; Loss tangent.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i2.6763               J. Sci. Res. 3 (2), 249-259 (2011)

Effect of aluminum nitride concentration on different physical properties of low density polyethylene based nanocomposites

2017 ◽  
Vol 37 (8) ◽  
pp. 765-775 ◽  
Author(s):  
Omer Bin Sohail ◽  
Osamah A. Bin-Dahman ◽  
Mostafizur Rahaman ◽  
Mamdouh A. Al-Harthi
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Aluminum Nitride ◽  
Tensile Modulus ◽  
Theoretical Models ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Scanning Calorimetry ◽  
Composite Systems ◽  
Present Composite

Abstract In this study, blends of low-density polyethylene (LDPE)/aluminum nitride (AlN) ceramic nanocomposites have been prepared through melt blending technique. Increased loading of AIN leads to reduction in tensile properties but improvement in rheological property (storage modulus). The rheological behavior tends to become unique at higher frequencies (≥10 rad/s). Differential scanning calorimetry (DSC) results show that the total crystallinity has decreased with the increase in AlN loading in the composites. It is seen that there is an improvement in electrical conductivity, dielectric constant, and flammability properties with the addition of AlN in the nanocomposites. The experimental data of tensile modulus, electrical conductivity, and dielectric constant have been fitted with some available theoretical models to check the models’ applicability for the present composite systems. Results show that only Nicolais-Nicodemo model, McCullough model, and Rahaman-Khastgir model are applicable for predicting the tensile modulus, electrical conductivity, and dielectric constant of the composites, respectively.

Analysis and testing of polymer matrix composites with thermoplastic liners having enhanced chemical resistance

2017 ◽  
Vol 36 (20) ◽  
pp. 1487-1502
Author(s):  
Luke P Djukic ◽  
Manudha T Herath ◽  
Daniel C Rodgers ◽  
Roderick Sweeting ◽  
Honesto Buendia
Keyword(s):  
Polymer Matrix ◽  
Chemical Resistance ◽  
Polymer Matrix Composites ◽  
Polyethylene Liner ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Matrix Composites ◽  
Linear Low Density Polyethylene ◽  
Dangerous Goods ◽  
Steel Tanks

Polymer matrix composite tanks offer major advantages to the transport industry in terms of increased payload and corrosion resistance compared to conventional steel tanks. Chemical resistance and versatility can be enhanced through the addition of a thermoplastic liner. This paper presents the results of chemical conditioning, testing and analysis of a linear low-density polyethylene liner, on its own and supported by carbon fiber reinforced polymer. Results are compared to ADR (European Agreement Concerning the International Carriage of Dangerous Goods by Road) requirements. The linear low-density polyethylene liner was tested in combination with 12–15% sodium hypochlorite and 98% sulphuric acid. The results indicate that the liner is suitable for service in tanks transporting these two chemicals. Liners were conditioned at 50℃ for periods of 1000 or 2000 h. Shore D hardness tests and three-point bend tests were performed, compared to unconditioned benchmarks, and found to pass ADR requirements. Finite element models were validated and used to facilitate understanding of the failure of the laminates. Predictions indicate that failure load increases with increased liner modulus, yield stress, and thickness. The models also indicate that the laminate strength and modulus is not significantly changed during chemical conditioning for the stated chemicals.

scholarly journals INFLUENCE OF ALUMINUM POWDER CONCENTRATION ON MECHANISM AND KINETIC REGULARITIES OF CRYSTALLIZATION OF COMPOSITES BASED ON LOW DENSITY POLYETHYLENE

2020 ◽  
Vol 63 (2) ◽  
pp. 77-83
Author(s):  
Najaf T. Kakhramanov ◽  
Khayala V. Allakhverdieva ◽  
Fatima A. Mustafayeva ◽  
Marat I. Abdullin
Keyword(s):  
Aluminum Powder ◽  
Polymer Matrix ◽  
Specific Volume ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Dilatometric Curve ◽  
First Order ◽  
Powder Concentration ◽  
First Order Phase Transition ◽  
First Order Phase

The results of the study of the influence of the aluminum powder concentration on the mechanism and the regularity of changes in the dependence of specific volume on temperature in the range of 25-180 °C in composites based on low density polyethylene are presented. By extrapolating the upper and lower branches of the dilatometric curve, approximate values of the glass transition temperature of the composites are found. Extrapolation of the lower branch of the dilatometric curve of the considered polymer composites to the absolute temperature allowed us to determine the value of the "occupied" specific volume and the "free" specific volume. Using the step dilatometry method, the temperature of the first-order phase transition of composites was found, which varies depending on the aluminum powder concentration in the composition of low density polyethylene. The concentration of aluminum powder with a particle size 1-2 µm varied between 0.5 – 30 wt. %. It has been established that the loading of 0.5 wt. % of aluminum powder practically does not affect the regularity of change in the dilatometric curve of the initial polymer matrix. At a filler concentration of 1.0 wt. % and higher, a significant change occurs in the regularities of change in these curves, expressed in a decrease in the value of the specific volume of the composites. A sharp decrease in the specific volume or an increase in the density of the composites in viscous-flow and solid states clearly indicated the reinforcing role of aluminum powder. In composites based on low density polyethylene, the dependence of the free specific volume on temperature and on the concentration of aluminum powder is determined. It is shown that an increase in the concentration of aluminum powder in the composition of low density polyethylene is accompanied by a regular decrease in the free volume of the polymer matrix. The obtained data confirms our idea that particles of aluminum powder are involved not only in the formation of heterogeneous crystallization centers, but are also forced into the amorphous region as the spherolite crystalline formations grow. In the coordinates of Avraami, the kinetic regularities of the process of isothermal crystallization in the region of the first-order phase transition are investigated. It has been established that with an increase in the degree of filling of the polymer matrix, the mechanism of crystallization from spherical (three-dimensional) type of growth of crystalline formations passes into a plate-like (two-dimensional) with the continuous formation of crystallization centers. Recommendations are given on the practical use of the results of a study of the crystallization process of composites as applied to the technology of their processing by injection molding.

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