Melt immiscibility in crosslinked polyethylene

Phillips, P. J.; Vatansever, Alican

doi:10.1002/pen.760300803

Cited by 8 publications

(5 citation statements)

References 8 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The self-assembly involving oppositely charged moieties 32 has the potential to address membrane mineralization, often experienced in anionic biomaterials. 7,[33][34] Fe 3+ system, 35 the carboxylic groups in HAs will be saturated with iron(III) during the self-assembly process, thus potentially preventing calcification and fouling on the sensor's surface. 36 Furthermore, the rich chemical environment in the HAs structure and the water-based self-assembly process may be easily employed for the attachment or coupling biologically active molecules such as growth factors, antifouling agents and drug delivery systems, which would further minimize the adverse tissue reactions to the implanted sensor.…”

Section: Introductionmentioning

confidence: 99%

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

et al. 2001

View full text Add to dashboard Cite

Multilayered films of humic acids (HAs) (naturally occurring biopolymers) were investigated as a potential semipermeable membrane for implantable glucose sensors. These films were grown using a layer-by-layer self-assembly process of HAs and oppositely charged ferric ions. The growth of these assemblies exhibited strong dependence on the pH and ionic strength of HAs solutions, which correlated with the degree of ionization of the carboxyl groups and neutralization-induced surface spreading. Quartz crystal microbalance (QCM) and ellipsometric studies have shown repeatable, stepwise increase in mass (as high as 5.63 microg/cm(2)) and in film thickness (ca. 24.3 nm per layer) for these assemblies. The permeability of glucose through these membranes can be regulated by varying the number of self-assembled HAs/Fe(3+) layers. Moreover, a 200 nm thick HAs/Fe(3+) film (in its hydrated state) had a shear modulus of about 80 MPa, implying stability upon implantation. These films were determined to be biocompatible since in vivo studies indicated only mild tissue reaction along with some neovascularization.

show abstract

Section: Introductionmentioning

confidence: 99%

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Water or electrical treeing has been considered one of the most important causes of failure. [2,3] Several electrical, thermal or mechanical mechanisms have been proposed, but it is difficult to interpret breakdown in dielectrics with a single mechanism. [4] Recent Full Paper: In this work the thermal behaviour of crosslinked low density polyethylene (XLPE) used as an insulator for commercial underground high tension (15 kV) cables was studied.…”

Section: Introductionmentioning

confidence: 99%

“…One consequence of this behaviour is the separation of the soluble and gel fractions in the polymer, to form a two phase melt in a narrow temperature range just above the melting point. [10,11] Considering the radial thermal gradient that transmission cables are subjected to during daily electrical load operation, the polymeric material may be partially molten and processes like self-nucleation, crystallisation and annealing may take place which, no doubt, would influence the dielectric response of the material during service and ageing.…”

Section: Introductionmentioning

confidence: 99%

Application of the SSA Calorimetric Technique to Characterise an XLPE Insulator Aged under Multiple Stresses

Paolini

Ronca

Feijoo

et al. 2001

Macromol. Chem. Phys.

View full text Add to dashboard Cite

In this work the thermal behaviour of crosslinked low density polyethylene (XLPE) used as an insulator for commercial underground high tension (15 kV) cables was studied. Three types of materials were selected: an uncrosslinked low density polyethylene (NXLPE) used as a control sample, an XLPE and an aged XLPE sample. The ageing conditions involved the application of multiple stresses: temperature, voltage and voltage impulses during 60 d under time and temperature cycles that are the most representative load of daily operation in Caracas, Venezuela. The effect of morphology segregation or thermal fractionation under multiple stresses conditions was analysed by measuring the percentage of crosslinking before and after the ageing tests were performed, and by investigating the thermal response of the material by conventional DSC and by the application of the successive self‐nucleation and annealing (SSA) thermal fractionation technique. The degree of crosslinking was found to vary in the material depending on the distance from the conductor because a thermal gradient is generated radially during the curing reaction. Such differences did not significantly affect the usual DSC heating scans of the samples. However, when SSA was applied, a difference in the distribution of thermal fractions was detected as a function of the distance towards the conductor that could be correlated to the variations in the crosslinking degree. After the accelerated ageing the thermal response of XLPE changes as evidenced by the presence of multiple melting peaks in subsequent DSC heating scans. This multiple melting was interpreted, as a first approximation, as arising from thermal fractionation during ageing (ignoring the possible effects of the other stresses applied) and SSA was able to simulate a similar fractionation that was very accurate in the prediction of the exact temperatures of the melting peaks produced.

show abstract

“…It is well known that when XLPE insulation reaches the temperature associated to the thermal gradient under which the insulation is degraded, the polymer may be partially molten, and self-nucleation, crystallization, and annealing processes may take place. Moreover, high electrical stress associated with the insulation screen cut back edge can contribute extensively to the deterioration of XLPE, leading to the development of electrical trees and breakdown at such points [22][23][24]. However, in all other cases, the joint stress control tube interface proved overwhelmingly to be the weakest entity in the joint system, thereby leading to longitudinal failure along the interface of the cable insulation and the stress controlling tubing.…”

Section: Modementioning

confidence: 94%

Effect of Accelerated Laboratory Aging on Selected Electrical Properties of Medium-voltage Heat Shrink Cable Joints

Qureshi

Al-Arainy

Malik

2014

Electric Power Components and Systems

View full text Add to dashboard Cite

Melt immiscibility in crosslinked polyethylene

Cited by 8 publications

References 8 publications

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

Characterization and Biocompatibility Studies of Novel Humic Acids Based Films as Membrane Material for an Implantable Glucose Sensor

Application of the SSA Calorimetric Technique to Characterise an XLPE Insulator Aged under Multiple Stresses

Effect of Accelerated Laboratory Aging on Selected Electrical Properties of Medium-voltage Heat Shrink Cable Joints

Contact Info

Product

Resources

About