Thermally stimulated depolarization current spectra of cross‐linked polyethylene and the influence of cross‐linking byproducts

Walker, Roger C.; Hamedi, Hossein; Woodward, W. Hunter; Lanagan, Michael T.

doi:10.1002/pol.20200470

Cited by 10 publications

(3 citation statements)

References 45 publications

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“…Meanwhile, the surface effect generated by the addition of BNNSs causes interfacial polarization between the composite and the test interface, thus leading to the increase of the relative dielectric constant of the composites. In addition, when the sample is vulcanized, the thermal decomposition of the vulcanizing agent Dicumyl Peroxide (DCP) produces cross-linking byproducts such as cumyl alcohol, acetophenone, etc [32,33] . The polar groups carried by these byproducts increase the dipole moment of the EPDM molecule, which increases the dielectric constant of the molecule.…”

Section: Dielectric Propertiesmentioning

confidence: 99%

Synergetic enhancement of the electrical-thermal-mechanical properties of EPDM composites modified by Kaolin and BNNSs

Feng,

Deng,

Xiao

et al. 2024

J Polym Res

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Offshore wind power is clean energy with rapid growth in recent years. As a key part of wind turbines, improving the combination performance of wind turbine cable insulation has a crucial impact on the development of wind power systems. In this paper, kaolin is selected to improve the tensile strength of Ethylene-Propylene-Diene Monomer (EPDM) rubber, and Boron Nitride Nanosheeets (BNNSs) with good electrical insulation and thermal conductivity are co-doped into kaolin/EPDM to improve the breakdown strength and thermal conductivity of the composite. The results show that the properties of the composites are improved when the powders are doped into EPDM. When the kaolin doping amount is 30wt%, the dielectric properties and the mechanical properties are improved, but the breakdown strength has deteriorated. Based on 30wt% kaolin content, BNNSs are added to EPDM. The breakdown strength is improved. The breakdown strength of the 30wt% Kaolin/5wt%BNNSs co-doped EPDM is 83.33kV/mm. In addition, due to the synergistic effect between the two powders, the tensile strength of the composite is increased to 8.06MPa. Meanwhile, with the increase of BNNSs, the thermal conductivity of composite is improved. It increases to 1.247 W/(m⋅K) This work has important guiding signi cance for improving the combination performance of the wind turbine cable insulation.

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Section: Dielectric Propertiesmentioning

confidence: 99%

Synergetic enhancement of the electrical-thermal-mechanical properties of EPDM composites modified by Kaolin and BNNSs

Feng,

Deng,

Xiao

et al. 2024

J Polym Res

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“…Instead, there was a clustering of the activation energy values around 0.15 eV and preexponential factor around 10 -10 S m -1 in AC measurement. These samples would retain significant amounts of DCP byproducts such as acetophenone, which produces space charge in the presence of water and cumyl alochol, which would decompose into water and methylstyrene [28]. While it has been reported that water addition will enhance the conductivity and decrease the activation energy [3,[29][30][31] and influence the preexponential factor [29,30] of polymers such as polyethylene, the presence of these chemical byproducts and their interaction with water must also be considered.…”

Section: Comparison Of DC and Acmentioning

confidence: 99%

Explanation of the Compensation Law and the Isokinetic Point in the Electrical Conduction of Crosslinked Polyethylene

Walker

Furman

Woodward

et al. 2022

International Journal of Polymer Science

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Thermally activated direct current (DC) electrical conductivity in low-density polyethylene (LDPE) is known to be subject to the compensation law. Accordingly, the preexponential factor follows a specific relation with activation energy, reducing overall changes in conductivity. This relationship is governed by the Meyer-Neldel temperature. However, there is no published evidence for a corresponding isokinetic point, a temperature where the conductivity of all LDPE samples is the same. Here, it is determined that the compensation law applies to both DC and alternating current (AC) conduction for LDPE and for crosslinked polyethylene (XLPE) without an observed isokinetic point. The potential origins of compensation in polyethylene are discussed as well as reasons for similarity between LDPE and XLPE. It is observed that prolonged water exposure removed the compensation behavior. Meanwhile, preheating samples in the oven prior to measurements modifies the compensation behavior and reduced the spread around the isokinetic point. It is thus deduced that an isokinetic point can be observed in polyethylene but is obscured by contributions from water and other impurities.

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“…As shown in Figure 4a-c, acetophenone was found in all three types of cable. Acetophenone is commonly used as a plasticizer or component of ink [20,21]. It probably originates from the inkjet printing on the cables.…”

Section: Compositional Analysis Of Gases Generated From Overheated Cablesmentioning

confidence: 99%

Odor Recognition of Thermal Decomposition Products of Electric Cables Using Odor Sensing Arrays

et al. 2021

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An odor sensing system with chemosensitive resistors was used to identify the gases generated from overheated cables to prevent fire. Three different electric cables for a distribution cabinet were used. The cables had an insulation layer made of polyvinyl chloride (PVC) or cross-linked polyethylene (XLPE). The heat resistance of the cables was tested by differential thermal and thermogravimetric analyses. The thermal decomposition products of the cables were investigated by gas chromatography-mass spectrometry (GC-MS). For the odor sensing system, two types of 16-channel array were used to detect the generated gases. One contains high-polarity GC stationary phase materials and the other contains GC stationary phase materials of high to low polarity. The system could distinguish among three cable samples at 270 °C with an accuracy of about 75% through both arrays trained with machine learning. Furthermore, the system could achieve a recall rate of 90% and a precision rate of 70% when the abnormal temperature was set above the cables’ allowable conductor temperature at 130 °C. The odor sensing system could effectively detect the abnormal heating of the cables before the occurrence of fire. Therefore, it is helpful for fire prediction and detection systems in factories and substations.

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Thermally stimulated depolarization current spectra of cross‐linked polyethylene and the influence of cross‐linking byproducts

Cited by 10 publications

References 45 publications

Synergetic enhancement of the electrical-thermal-mechanical properties of EPDM composites modified by Kaolin and BNNSs

Synergetic enhancement of the electrical-thermal-mechanical properties of EPDM composites modified by Kaolin and BNNSs

Explanation of the Compensation Law and the Isokinetic Point in the Electrical Conduction of Crosslinked Polyethylene

Odor Recognition of Thermal Decomposition Products of Electric Cables Using Odor Sensing Arrays

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