scholarly journals Thermal and Mechanical Behavior of Elastomers Incorporated with Thermoregulating Microcapsules

2021 ◽  
Vol 11 (12) ◽  
pp. 5370
Author(s):  
Ana M. Borreguero ◽  
Irene Izarra ◽  
Ignacio Garrido ◽  
Patrycja J. Trzebiatowska ◽  
Janusz Datta ◽  
...  
Keyword(s):  
Latent Heat ◽  
Continuous Improvement ◽  
Low Density Polyethylene ◽  
Molar Ratio ◽  
Low Density ◽  
Minimum Particle Size ◽  
Synergy Effects ◽  
Elastomeric Materials ◽  
The Matrix ◽  
Spherical Microparticles

Polyurethane (PU) is one of the principal polymers in the global plastic market thanks to its versatility and continuous improvement. In this work, PU elastomeric materials having thermoregulating properties through the incorporation of microcapsules (mSD-(LDPE·EVA-RT27)) from low-density polyethylene and vinyl acetate containing paraffin®RT27 as PCM were produced. Elastomers were synthesized while varying the molar ratio [NCO]/[OH] between 1.05 and 1.1 and the microcapsule (MC) content from 0.0 to 20.0 wt.%. The successful synthesis of the PUs was confirmed by IR analyses. All the synthesized elastomers presented a structure formed by a net of spherical microparticles and with a minimum particle size for those with 10 wt.% MC. The density and tensile strength decreased with the MC content, probably due to worse distribution into the matrix. Elastomer E-1.05 exhibited better structural and stability properties for MC contents up to 15 wt.%, whereas E-1.1, containing 20 wt.% MC, revealed mechanical and thermal synergy effects, demonstrating good structural stability and the largest latent heat. Hence, elastomers having a large latent heat (8.7 J/g) can be produced by using a molar ratio [NCO]/[OH] of 1.1 and containing 20 wt.% mSD-(LDPE·EVA-RT27).

The synthesis of organically modified layered double hydroxide and its effect on the structure and physical properties of low-density polyethylene/ethylene–vinyl acetate blends

2019 ◽  
Vol 27 (5) ◽  
pp. 287-298
Author(s):  
Xincheng Guo ◽  
Mengqi Tang ◽  
Na Wang ◽  
Lingtong Li ◽  
Yifan Wu ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Layered Double Hydroxide ◽  
Organic Anion ◽  
Ethylene Vinyl Acetate ◽  
Degree Of Crystallinity ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Organically Modified ◽  
The Matrix ◽  
Double Hydroxide

Organically modified layered double hydroxide (OM-LDH) was synthesized via anion exchange reaction and potassium monolauryl phosphate (MAPK) was used as an intercalator. The OM-LDH nanofillers were embedded into low-density polyethylene/ethylene–vinyl acetate (LDPE/EVA) via melt blending process which provided LDPE/EVA/OM-LDH nanocomposites. The structure and properties of the fabricated samples were characterized through Fourier transform infrared spectroscopy, X-ray diffraction techniques, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and tensile testing. The results showed that the organic anion was intercalated into the interlayer region of LDH and enlarged the interlayer distance. The TGA results of the nanocomposites showed significantly improved thermal stability at a higher temperature when containing 6 wt% OM-LDH due to the good dispersion of OM-LDH in the matrix. The DSC data indicated that the degree of crystallinity was increased obviously due to the incorporation of OM-LDH in the matrix. The formation of organic side chains on the OM-LDH surface also contributed to an improvement in the interfacial adhesion, resulting in enhanced tensile strength and elongation at break compared with LDH.

On the durability of low-density polyethylene nanocomposites

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Jitendra K. Pandey ◽  
Raj Pal Singh
Keyword(s):  
Ir Spectroscopy ◽  
Morphological Changes ◽  
Diffusion Path ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Neat Polymer ◽  
The Matrix ◽  
Ft Ir ◽  
The Stability ◽  
Artificial Uv

Abstract Low-density polyethylene (PE) containing nano-particulate clay was prepared after functionalization with maleic anhydride (MA) by reactive grafting in the presence of peroxide followed by blending of maleated PE with neat polymer in different concentrations. Four classes of composites were obtained: (i) exfoliated, (ii) intercalated, (iii) microcomposites, and (iv) intermediate of intercalated and microcomposites, as evidenced by wide-angle X-ray diffraction. All samples were kept for artificial UV irradiation (λ ≥ 290 nm) and for composting to study their photo- and bio-durability. Fourier-transform IR spectroscopy (FT-IR) and scanning electron microscopy were used to monitor the functional group and morphological changes, respectively, whereas biodurability was evaluated by measuring the weight loss. MA functionalization and nature of composites have detrimental effects on the overall durability of composites. Nanocomposites showed higher resistance than microcomposites during initial weathering and composting with a long induction period. The stability of nanocomposites decreases with time and overall durability was worse than of pristine polymer in both environments. It was concluded that the initial protection is due to the filler-generated long diffusion path, which decreases the oxygen diffusion through the matrix. The bio-durability of composites decreased with oxo-degradation. Biodegradation of PE nanocomposites during composting follows the mechanism described by Albertsson et al. as evidenced by FT-IR spectroscopy.

Operation and Maintenance of Hyper Compressor in LDPE Plant

2011 ◽  
Author(s):  
Abang Azian Abang Mok ◽  
Muhd Hafiz B. Hj Ghani ◽  
Alias B. Kadir
Keyword(s):  
Continuous Improvement ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Original Equipment Manufacturer ◽  
Equipment Manufacturer ◽  
Operation And Maintenance ◽  
Maintenance Activities ◽  
The Right ◽  
Production Target

Petlin (Malaysia) Sdn Bhd was incorporated in March 1999 and has a Low Density Polyethylene plant that was commissioned in February 2002. The plant has a capacity of 255,000 tons per annum. The aim of the plant is to generate a reasonable return by manufacturing top quality products. To realize this aim, it’s important for the operators of the plant to operate the machines in accordance to the parameters set by the original equipment manufacturer. This will also ensure the availability and reliability of the plant. It is also important to regularly monitor the performance of the plant in relation to the operation and maintenance activities in order to prepare a better plan for continuous improvement. The Hyper-Compressors are the most fragile component in the system as they’re running under fatigue conditions and high operating pressures. It is essential to have the right processes and procedures in place to ensure that safety is not compromise in meeting the production target.

Optimization of the cellular morphology of biaxially stretched thin polyethylene foams produced by extrusion film blowing

2018 ◽  
Vol 37 (4-6) ◽  
pp. 153-168 ◽  
Author(s):  
Ouassim Hamdi ◽  
Frej Mighri ◽  
Denis Rodrigue
Keyword(s):  
Cellular Structure ◽  
Blow Up ◽  
Nucleating Agent ◽  
Processing Parameters ◽  
Matrix Composition ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Aspect Ratios ◽  
The Matrix ◽  
A Cell

This work presents the production of cellular polymer films using extrusion blowing to impose biaxial stretching on the cellular structure while processing. The materials selected are linear low-density polyethylene (LLDPE) and low density polyethylene (LDPE) as the matrix, azodicarbonamide as the chemical blowing agent, and talc as the nucleating agent. The processing parameters, namely, the temperature profile, screw speed, feed rate, take-up ratio, blow-up ratio, and the matrix composition were all optimized to produce a homogeneous cellular structure with defined morphologies. The optimized films had a thickness below 300 µm, a relative density around 0.6, a cell density above 2 × 106 cells/cm3, and biaxially stretched cells with aspect ratios above 4 longitudinally and 3.8 transversally.

scholarly journals Role of Chemically Functionalization of Bamboo Fibers on Polyethylene-Based Composite Performance: A Solution for Recycling

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2564
Author(s):  
Meisam Kouhi ◽  
Simona Butan ◽  
Yang Li ◽  
Elias Shakour ◽  
Mihaela Banu
Keyword(s):  
Natural Fibers ◽  
High Volume ◽  
Mechanical Tests ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Plastic Bags ◽  
Depth Analysis ◽  
The Matrix ◽  
Bamboo Fibers ◽  
Recycled Low Density Polyethylene

Low-density polyethylene is the most common polymer for manufacturing containers, bottles, tubes, plastic bags, computer components and so on. There is an urgent need to find solutions for its recycling and reintegration in high volume production components such as non-structural auto applications. The reinforcement of recycled low-density polyethylene with natural fibers represents a solution for the re-use of the recycled low-density polyethylene. However, there is a lack of understanding of how the natural fibers influence the behavior of the bare low-density polyethylene, and furthermore, how the interface between the fibers and the matrix can be controlled in composite to obtain the designed toughness, strength, stiffness and damping. In this sense, the study presents an in-depth analysis of the behavior of three coupling agents used in the chemically functionalized bamboo fibers interface for reinforcing low-density polyethylene composites. Through mechanical tests, the mechanical properties are determined and compared and finally, a correlation between the viscous behavior of the resulted composites and the toughening mechanism is proposed. The conclusion of the study enables a flexible design of polymer composite components fabricated of recycled and non-recycled low-density polyethylene and natural fibers.

scholarly journals The Effect of Adding Halloysite Nanotubes as Filler on the Mechanical Properties of Low-Density Polyethylene

2018 ◽  
Vol 919 ◽  
pp. 144-151 ◽  
Author(s):  
Ľudmila Dulebová ◽  
Karolina Glogowska ◽  
Jaroslav Hájek ◽  
Jakub Fic
Keyword(s):  
Mechanical Properties ◽  
Charpy Impact ◽  
Polymeric Materials ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Halloysite Nanotubes ◽  
Low Density Polyethylene ◽  
Low Density ◽  
The Matrix ◽  
Static Tensile

Reinforcing thermoplastic polymers with nanotubes or nanoplatelets to form nanocomposites is a way to increase the usage of polymeric materials in engineering applications by improving their mechanical properties. The contribution presents the results of research from basic processing and mechanical properties of nanocomposites. Low-Density Polyethylene (LDPE) was used as a matrix for experiments. The material LDPE was modified by Halloysite nanotubes (HNT) with a mass share of 2, 4, 6 wt% of the matrix. Nanocomposites were filled with 5 wt% Polyethylene grafted with maleic anhydride (PE-graft-MA) as a compatibilizer. The specimens were prepared by injection molding and their selected mechanical properties were tested by static tensile test, Charpy impact test and Shore hardness test.

Influence of Nano-Filler Type on Technological Processing and Resulting Mechanical Properties

2019 ◽  
Vol 952 ◽  
pp. 180-187
Author(s):  
Martin Reznicek ◽  
Dagmar Měřínská ◽  
Martin Ovsik ◽  
Michal Stanek ◽  
Adam Dockal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Positive Impact ◽  
Strength Test ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Tensile Strength Test ◽  
The Matrix ◽  
Technological Processing ◽  
The Individual

Modification of polymers by fillers is one of the most used material alterations to improve its required properties. This article is about modification of polymer matrix by fillers with layered particles. Linear low density polyethylene (LLDPE) was used as matrix and it was mixed with different kinds of fillers. Fillers used were: CaPhP – Calcium Phenylphosphonate, double layered hydroxides (ZnAl-DDS, ZnAl-lac and ZnAl-CO3) and natural Talc. Individual fillers were mixed into the matrix by kneading machine with the use of several velocities. The article focuses on influence of the individual filler on mechanical properties measured by tensile strength test. This paper also investigates the problem of process parameters’ influence on final mechanical properties and later confirms positive impact of all fillers that were used, although the size of them differs.

scholarly journals EFFECT OF IMPERATA CYLINDRICA REINFORCEMENT FORM ON THE TENSILE AND IMPACT PROPERTIES OF ITS COMPOSITES WITH RECYCLED LOW DENSITY POLYETHYLENE

2018 ◽  
Vol 58 (5) ◽  
pp. 292
Author(s):  
Olusola Femi Olusunmade ◽  
Abba Emmanuel Bulus ◽  
Terwase Kelvin Kashin
Keyword(s):  
Economic Value ◽  
Tensile Modulus ◽  
Natural Fibre ◽  
Imperata Cylindrica ◽  
Low Density Polyethylene ◽  
Fibre Reinforcement ◽  
Low Density ◽  
Impact Properties ◽  
The Matrix ◽  
Recycled Low Density Polyethylene

Composites of recycled low-density polyethylene obtained from waste water-sachets and imperata cylindrica were produced with particulate and long-fibre unidirectional mat reinforcements. Comparison was made of the tensile and impact properties resulting from the use of the different reinforcement forms at 10 wt% ratio in the matrix. The results obtained from the tests carried out revealed that tensile strength, tensile modulus, elongation at break and impact strength of the composite with the long-fibre mat reinforcement were better than those of the one composite with the particulate reinforcement. The better performance observed in the long-fibre mat reinforcement could be attributed to the retention of the toughness and stiffness of the imperata cylindrica stem in this form of reinforcement, which is lost after the stem strands are pulverized into particles. Imperata cylindrica stem, as a natural fibre reinforcement for polymetric material is, therefore, recommended in the long-fibre mat form. The combination of these otherwise challenging resources in composite materials development will add economic value to them and help to reduce the nvironmental menace they present.

scholarly journals Dielectric and AC Breakdown Properties of SiO2/MMT/LDPE Micro–Nano Composites

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1235
Author(s):  
Hongtao Jiang ◽  
Xiaohong Zhang ◽  
Junguo Gao ◽  
Ning Guo
Keyword(s):  
Experimental Data ◽  
Field Strength ◽  
Dielectric Constants ◽  
Low Density Polyethylene ◽  
Breakdown Field ◽  
Nano Composites ◽  
Low Density ◽  
Inorganic Particles ◽  
The Matrix ◽  
Breakdown Field Strength

Low-density polyethylene (LDPE) is an important thermoplastic material which can be made into films, containers, wires, cables, etc. It is highly valued in the fields of packaging, medicine, and health, as well as cables. The method of improving the dielectric property of materials by blending LDPE with inorganic particles as filler has been paid much attention by researchers. In this paper, low-density polyethylene is used as the matrix, and montmorillonite (MMT) particles and silica (SiO2) particles are selected as micro and nano fillers, respectively. In changing the order of adding two kinds of particles, a total of five composite materials were prepared. The crystallization behavior and crystallinity of five kinds of composites were observed, the εr and tanδ changes of each material were investigated with frequency and temperature, and the power frequency (50 Hz) AC breakdown performance of materials were measured. The differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results show that the crystallinity of the composites is higher than that of LDPE. Experimental data of dielectric frequency spectra show that the dielectric constants of micro–nano composites and composites with added MMT particles are lower than LDPE, the dielectric loss of composites can be improved by adding MMT particles. The experimental data of dielectric temperature spectra show that the permittivity of SiO2-MMT/LDPE is still at a low level under the condition of 20~100 °C. In terms of breakdown field strength, the SiO2/LDPE composite material increased by about 17% compared with the matrix LDPE, and the breakdown field strength of the materials SiO2-MMT/LDPE and MMT-SiO2/LDPE increased by about 6.8% and 4.6%, respectively.

scholarly journals Effect of Crystallinity of Polyethylene with Different Densities on Breakdown Strength and Conductance Property

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1746 ◽  
Author(s):  
Dawei Li ◽  
Liwei Zhou ◽  
Xuan Wang ◽  
Lijuan He ◽  
Xiong Yang
Keyword(s):  
Field Strength ◽  
Continuous Improvement ◽  
High Density Polyethylene ◽  
Breakdown Strength ◽  
Characteristic Curve ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
X Ray Diffraction ◽  
X Ray

In order to study the effects of the crystallinity of polyethylene with different densities on breakdown strength and conductance properties, this paper mainly tests the X-ray diffraction (XRD), different scanning calorimeter (DSC), direct current (DC) breakdown and conductance properties of low-density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), and high-density polyethylene (HDPE), and further analyzes the experimental results separately. The results show that an increase in the density of polyethylene leads to the continuous improvement of crystallinity, and an increase in crystallinity causes a significant decrease in the conduction current at the same field strength. The field strength corresponding to the two turning points in the conductance characteristic curve increases simultaneously.

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