Paramagnetic‐Resonance Studies of Irradiated High‐Density Polyethylene. II. Effect of Irradiation Dose on the Radical Species Trapped at Room Temperature

1960 ◽  
Vol 33 (2) ◽  
pp. 405-412 ◽  
Author(s):  
Elliott J. Lawton ◽  
J. S. Balwit ◽  
R. S. Powell
Keyword(s):  
High Density Polyethylene ◽  
Irradiation Dose ◽  
Room Temperature ◽  
High Density ◽  
Radical Species ◽  
Paramagnetic Resonance

scholarly journals Numerical and experimental study of the Behaviour of notched HDPE

2021 ◽  
Vol 229 ◽  
pp. 01002
Author(s):  
Rabiaa Elkori ◽  
Amal Laamarti ◽  
Khalid Elhad ◽  
Abdelilah Hachim
Keyword(s):  
Experimental Study ◽  
Tensile Test ◽  
High Density Polyethylene ◽  
Room Temperature ◽  
Industrial Applications ◽  
High Density ◽  
Deformation Mechanisms ◽  
Commercial Software ◽  
Notched Specimens ◽  
Software Code

It is important to study the Behaviour of high-density polyethylene (HDPE) under notch effects as it is widely used in industrial applications (Qi, 2018). However, there are only a few studies on the Behaviour of HDPE with defects, this work aims to study the deformation mechanisms under a tensile test experimentally performed on blank and notched specimens at constant speed and room temperature, and by developing our study by simulating HDPE using commercial software code.

scholarly journals The High Density Polyethylene Composite with Recycled Radiation Cross-Linked Filler of rHDPEx

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1361 ◽  
Author(s):  
David Manas ◽  
Miroslav Manas ◽  
Ales Mizera ◽  
Pavel Stoklasek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behaviour ◽  
Composite Structure ◽  
High Density Polyethylene ◽  
Industrial Waste ◽  
Room Temperature ◽  
High Density ◽  
Polyethylene Composite ◽  
Processing Properties ◽  
Better Than

This article discusses the possibilities of using radiation cross-linked high density polyethylene (HDPEx) acting as a filler in the original high density polyethylene (HDPE) matrix. The newly created composite is one of the possible answers to questions relating to the processing of radiation cross-linked thermoplastics. Radiation cross-linked networking is—nowadays, a commonly used technology that can significantly modify the properties of many types of thermoplastics. This paper describes the influence of the concentration of filler, in the form of grit or powder obtained by the grinding/milling of products/industrial waste from radiation cross-linked high density polyethylene (rHDPEx) on the mechanical and processing properties and the composite structure. It was determined that, by varying the concentration of the filler, it is possible to influence the mechanical behaviour of the composite. The mechanical properties of the new composite—measured at room temperature, are generally comparable or better than the same properties of the original thermoplastic. This creates very good assumptions for the effective and economically acceptable, processing of high density polyethylene (rHDPEx) waste. Its processability however, is limited; it can be processed by injection moulding up to 60 wt %.

scholarly journals Electron-paramagnetic-resonance studies on a photochemically produced species of horseradish peroxidase compound I

1977 ◽  
Vol 167 (1) ◽  
pp. 31-37 ◽  
Author(s):  
A R McIntosh ◽  
M J Stillman
Keyword(s):  
Electron Paramagnetic Resonance ◽  
New Species ◽  
Horseradish Peroxidase ◽  
Room Temperature ◽  
Resonance Signal ◽  
Compound I ◽  
Radical Species ◽  
Strong Electron ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Strong electron-paramagnetic-resonance signals in the g = 2.00 region were detected after irradiation of horseradish peroxidase Compound I at temperatures of 10 and 100 K. These signals establish the presence of new free-radical species in the peroxidase system. The new species are interpreted in terms of a haem-photosensitized oxidation of the protein's peptide groups close to the Compound I radical site. On warming to room temperature, the radicals decayed irreversibly to a species having a weak asymmetric electron-paramagnetic-resonance signal at 100 K, which could still be observed after incubation at room temperature for more than 1 h.

scholarly journals Carbon Fibers from High-Density Polyethylene Using a Hybrid Cross-Linking Technique

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2157
Author(s):  
Seong-Hyun Kang ◽  
Kwan-Woo Kim ◽  
Byung-Joo Kim
Keyword(s):  
Electron Beam ◽  
Sulfuric Acid ◽  
Carbon Fibers ◽  
High Density Polyethylene ◽  
Irradiation Dose ◽  
High Density ◽  
Cross Linking ◽  
Fiber Morphology ◽  
Hybrid Cross

In this study, a method for manufacturing high-density polyethylene (HDPE)-based carbon fibers using a hybrid cross-linking method was studied. HDPE precursor fibers were first cross-linked with an electron beam (E-beam) at an irradiation dose of 1000–2500 kGy, and then cross-linked in sulfuric acid at 80–110 °C for 60 min. Hybrid crosslinked fibers were carbonized for 5 min at a temperature of 900 °C. As a result, the hybrid crosslinked fibers had a carbonization yield of 40%. In addition, the carbonized fibers after hybrid crosslinking exhibited perfect fiber morphology, and HDPE-based carbon fibers with (002) and (10l) peaks, which are the intrinsic XRD peaks of carbon fibers, were successfully prepared.

scholarly journals On orientation memory in high density polyethylene – carbon nanofibers composites

e-Polymers ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Mircea Chipara ◽  
Brian Jones ◽  
Dorina M. Chipara ◽  
Jianhua Li ◽  
Karen Lozano ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Carbon Nanofibers ◽  
Crystalline Phase ◽  
High Density Polyethylene ◽  
Room Temperature ◽  
Uniaxial Stress ◽  
High Density ◽  
Two Dimensional ◽  
Uniaxial Stretching ◽  
X Ray

AbstractAn orientation memory effect in high density polyethylene (HDPE) filled with vapor grown carbon nanofibers (VGCNF) is reported. Two-dimensional X-ray (2DXR) confirmed the reorientation of HDPE crystallites upon the uniaxial stretching of HDPE and HDPE filled by VGCNFs. This anisotropy of 2DXR spectra was decreased by heating all stretched samples (loaded or not loaded by VGCNFs) from room to the melting temperature of HDPE. Upon cooling these samples to room temperature, it was noticed that only the nanocomposite retained a weak partial (uniaxial) order, while HDPE showed a completely isotropic 2DXR spectrum. It was concluded that during the stretching of nanocomposites the crystallites and VGCNFs were aligned along the uniaxial stress. Upon heating, the crystalline phase was melted, while the orientation of the VGCNFs was not significantly disturbed. The recrystallization of the polymer started preferentially from the VGCNF – polymer interphase, resulting into an anisotropic crystalline structure.

scholarly journals Fotodegradasi High Density Polyethylene Yang Mengandung Aditif Okso-Biodegradasi

2017 ◽  
Vol 4 (2) ◽  
pp. 402-405
Author(s):  
Ristika O. Asriza ◽  
Janiar Pitulima
Keyword(s):  
Mechanical Properties ◽  
Carbonyl Group ◽  
Wavelength Range ◽  
High Density Polyethylene ◽  
Room Temperature ◽  
Uv Light ◽  
High Density ◽  
Absorption Peak ◽  
Metal Compound ◽  
Peak Intensity

High Density Polyethylene (HDPE) is a type of plastic that widely used for packaging because it has good mechanical properties. HDPE is naturally non-biodegradable, and  the consequence it will increase plastic waste that will damage the environment. To increase their biodegradability, it is necessary to add an oxo-biodegradation additive in the form of a stearate metal compound. This oxo-biodegradation additive is a chromophore that can absorb UV light. Polyethylene oxo-biodegradation films are prepared by mixing HDPE and cobalt stearate to homogeneous on various compositions. To know the effect of adding cobalt stearate into HDPE has done by photodegradation  process. The polyethylene oxo-biodegradation film was given irradiation using UV light in the wavelength range 280-300 nm at room temperature for 10 days. After irradiation, in the ATR spectrum shows an absorption  peak at 1712 cm-1 wavenumber indicatied  the presence of a carbonyl group with a stronger intensity. The higher concentration of cobalt stearate added in HDPE, increases the peak intensity of carbonyl group. This is due to the increasing number of chromophores from cobalt stearate that can absorb UV light, the faster the breakdown of HDPE chains into small fragments so that HDPE is rapidly degraded in nature.

Cesium Ion Implantation in Single Crystal Yttria-Stabilized Zirconia (YSZ) and Polycrystalline MgAl2O4-YSZ

2002 ◽  
Vol 713 ◽  
Author(s):  
S. Zhu ◽  
X.T. Zu ◽  
L.M. Wang ◽  
R.C. Ewing
Keyword(s):  
Ion Implantation ◽  
Room Temperature ◽  
High Density ◽  
In Situ Tem ◽  
Paramagnetic Resonance ◽  
Inert Matrix ◽  
Electron Paramagnetic ◽  
Cs Ions ◽  
Small Bubbles

ABSTRACTYSZ and MgAl2O4-YSZ composite are two promising materials as in the inert matrix nuclear fuel for the incineration of plutonium. In this study, 400 keV Cs ions were implanted to a fluence of 1×1017 ions/m2 in both materials in order to investigate the retention behavior of fission product at elevated temperature. The implantations were completed at room temperature for the YSZ and 973 K for MgAl2O4-YSZ, respectively. Subsequent annealing at 1273 K was performed after a room temperature implantation of YSZ. After annealing, a high density of gas bubbles formed with diameter from 3 to 40 nm from the surface to a depth of 150 nm in the YSZ matrix. The swelling due to bubbles formation was estimated to be 2.5%. In situ TEM was employed during high temperature ion implantation of the MgAl2O4-YSZ composite. A high density of small bubbles with 5 nm in diameter formed in the MgAl2O4 and YSZ grains after an ion dose of 1×1017 ions/cm2. There was no preferential precipitation along grain boundaries. Electron Paramagnetic resonance (EPR) spectroscopy was used to investigate the type of defects that formed in the YSZ matrix.

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