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Pourrahimi AM, Mauri M, D'Auria S, Pinalli R, Müller C. Alternative Concepts for Extruded Power Cable Insulation: from Thermosets to Thermoplastics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2313508. [PMID: 38607958 DOI: 10.1002/adma.202313508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/04/2024] [Indexed: 04/14/2024]
Abstract
The most common type of insulation of extruded high-voltage power cables is composed of low-density polyethylene (LDPE), which must be crosslinked to adjust its thermomechanical properties. A major drawback is the need for hazardous curing agents and the release of harmful curing byproducts during cable production, while the thermoset nature complicates reprocessing of the insulation material. This perspective explores recent progress in the development of alternative concepts that allow to avoid byproducts through either click chemistry type curing of polyethylene-based copolymers or the use of polyolefin blends or copolymers, which entirely removes the need for crosslinking. Moreover, polypropylene-based thermoplastic formulations enable the design of insulation materials that can withstand higher cable operating temperatures and facilitate reprocessing by remelting once the cable reaches the end of its lifetime. Finally, polyethylene-based covalent and non-covalent adaptable networks are explored, which may allow to combine the advantages of thermoset and thermoplastic insulation materials in terms of thermomechanical properties and reprocessability.
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Affiliation(s)
- Amir Masoud Pourrahimi
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, 41296, Sweden
| | - Massimiliano Mauri
- Department of Materials Engineering, Nexans Norway AS, Knivsøveien 70, Berg i Østfold, 1788, Norway
| | - Silvia D'Auria
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Roberta Pinalli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, 41296, Sweden
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Karlsson ME, Xu X, Hillborg H, Ström V, Hedenqvist MS, Nilsson F, Olsson RT. Lamellae-controlled electrical properties of polyethylene - morphology, oxidation and effects of antioxidant on the DC conductivity. RSC Adv 2020; 10:4698-4709. [PMID: 35495223 PMCID: PMC9049201 DOI: 10.1039/c9ra09479b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/18/2020] [Indexed: 11/21/2022] Open
Abstract
Destruction of the spherulite structure in low-density polyethylene (LDPE) is shown to result in a more insulating material at low temperatures, while the reverse effect is observed at high temperatures. On average, the change in morphology reduced the conductivity by a factor of 4, but this morphology-related decrease in conductivity was relatively small compared with the conductivity drop of more than 2 decades that was observed after slight oxidation of the LDPE (at 25 °C and 30 kV mm-1). The conductivity of LDPE was measured at different temperatures (25-60 °C) and at different electrical field strengths (3.3-30 kV mm-1) for multiple samples with a total crystalline content of 51 wt%. The transformation from a 5 μm coherent structure of spherulites in the LDPE to an evenly dispersed random lamellar phase (with retained crystallinity) was achieved by extrusion melt processing. The addition of 50 ppm commercial phenolic antioxidant to the LDPE matrix (e.g. for the long-term use of polyethylene in high voltage direct current (HVDC) cables) gave a conductivity ca. 3 times higher than that of the same material without antioxidants at 60 °C (the operating temperature for the cables). For larger amounts of antioxidant up to 1000 ppm, the DC conductivity remained stable at ca. 1 × 10-14 S m-1. Finite element modeling (FEM) simulations were carried out to model the phenomena observed, and the results suggested that the higher conductivity of the spherulite-containing LDPE stems from the displacement and increased presence of polymeric irregularities (formed during crystallization) in the border regions of the spherulite structures.
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Affiliation(s)
- Mattias E Karlsson
- Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology SE-100 44 Stockholm Sweden +46 8208856 +46 87906000
| | - Xiangdong Xu
- Department of Materials and Manufacturing Technology, Chalmers University of Technology SE-412 96 Gothenburg Sweden
| | | | - Valter Ström
- Material Science and Engineering, School of Industrial Engineering and Management, KTH Royal Institute of Technology SE-100 44 Stockholm Sweden
| | - Mikael S Hedenqvist
- Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology SE-100 44 Stockholm Sweden +46 8208856 +46 87906000
| | - Fritjof Nilsson
- Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology SE-100 44 Stockholm Sweden +46 8208856 +46 87906000
| | - Richard T Olsson
- Department of Fibre and Polymer Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology SE-100 44 Stockholm Sweden +46 8208856 +46 87906000
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Ren Y, Wu K, Coker DF, Quirke N. Thermal transport in model copper-polyethylene interfaces. J Chem Phys 2019; 151:174708. [PMID: 31703489 DOI: 10.1063/1.5123616] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Thermal transport through model copper-polyethylene interfaces is studied using two-temperature nonequilibrium molecular dynamics. This approach treats electronic and phonon contributions to the thermal transport in the metallic region, but only phonon mediated transport is assumed in the polymer. Results are compared with nonequilibrium molecular dynamics simulations of heat transport in which only phonon contributions are incorporated. The influence of the phase of the polymer component (crystalline, amorphous, and lamella) and, where relevant, its orientation relative to the metallic interface structure is explored. These computational studies suggest that the thermal conductivity of the metal-polymer interface can be more than 40 times greater when the polymer chains of the lamella are oriented perpendicular to the interface than the situation when the interface is formed by an amorphous polymer or a crystalline polymer phase in which the chains orient parallel to the interface. The simulations suggest that the phonon contribution to the thermal conductivity of the copper region can be increased by as much as a factor of three when coupling between the electrons and phonons in the metal region is incorporated. This, combined with the explicit inclusion of the purely electronic component of the thermal transport in the metal region, can lead to a substantial increase in the heat flux promoted by the interface while maintaining a constant temperature drop. These simulation results have important implications for designing materials that have excellent electrical insulation properties but can also be highly effective in heat conduction.
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Affiliation(s)
- Yuanyang Ren
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049, Shaanxi, China
| | - Kai Wu
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, 28 Xianning West Road, Xi'an 710049, Shaanxi, China
| | - David F Coker
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA
| | - Nick Quirke
- Department of Chemistry, Imperial College 301G Molecular Sciences Research Hub White City Campus, 80 Wood Lane, London W12 OBZ, United Kingdom
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Li L, Zhong L, Zhang K, Gao J, Xu M. Temperature Dependence of Mechanical, Electrical Properties and Crystal Structure of Polyethylene Blends for Cable Insulation. MATERIALS 2018; 11:ma11101922. [PMID: 30304869 PMCID: PMC6213639 DOI: 10.3390/ma11101922] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 09/28/2018] [Accepted: 10/03/2018] [Indexed: 11/17/2022]
Abstract
There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.
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Affiliation(s)
- Lunzhi Li
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Lisheng Zhong
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Kai Zhang
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Jinghui Gao
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Man Xu
- State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049, China.
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Seven KM, Cogen JM, Person T, Reffner JR, Gilchrist JF. The effect of inorganic and organic nucleating agents on the electrical breakdown strength of polyethylene. J Appl Polym Sci 2018. [DOI: 10.1002/app.46325] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Karl M. Seven
- The Dow Chemical Company, 400 Arcola Road; Collegeville Pennsylvania 19426-2914
- Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem Pennsylvania 18015-2914
| | - Jeffrey M. Cogen
- The Dow Chemical Company, 400 Arcola Road; Collegeville Pennsylvania 19426-2914
| | - Tim Person
- The Dow Chemical Company, 400 Arcola Road; Collegeville Pennsylvania 19426-2914
| | - John R. Reffner
- The Dow Chemical Company, 400 Arcola Road; Collegeville Pennsylvania 19426-2914
| | - James F. Gilchrist
- Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem Pennsylvania 18015-2914
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Saiz F, Cubero D, Quirke N. The excess electron at polyethylene interfaces. Phys Chem Chem Phys 2018; 20:25186-25194. [DOI: 10.1039/c8cp01330f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This work investigates the energy and spatial properties of excess electrons in polyethylene in bulk phases and, for the first time, at amorphous vacuum interfaces using a pseudopotential single-electron method (Lanczos diagonalisation) and density functional theory (DFT).
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Affiliation(s)
- Fernan Saiz
- Department of Chemistry
- Imperial College
- London
- UK
| | - David Cubero
- Departmento de Física Aplicada I
- Escuela Politécnica Superior
- Universidad de Sevilla
- Seville
- Spain
| | - Nick Quirke
- Department of Chemistry
- Imperial College
- London
- UK
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Rytöluoto I, Gitsas A, Pasanen S, Lahti K. Effect of film structure and morphology on the dielectric breakdown characteristics of cast and biaxially oriented polypropylene films. Eur Polym J 2017. [DOI: 10.1016/j.eurpolymj.2017.08.051] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wang Y, MacKernan D, Cubero D, Coker DF, Quirke N. Single electron states in polyethylene. J Chem Phys 2014. [DOI: 10.1063/1.4869831] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Nilsson S, Hjertberg T, Smedberg A, Sonerud B. Influence of morphology effects on electrical properties in XLPE. J Appl Polym Sci 2011. [DOI: 10.1002/app.34006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Huang X, Xie L, Jiang P, Wang G, Yin Y. Morphology studies and ac electrical property of low density polyethylene/octavinyl polyhedral oligomeric silsesquioxane composite dielectrics. Eur Polym J 2009. [DOI: 10.1016/j.eurpolymj.2009.05.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wang X, Tu DM, Lei C, Du QG. Insulation performance and microstructure in modified polyethylene by MPE. J Appl Polym Sci 2008. [DOI: 10.1002/app.26735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hoyos M, García N, Navarro R, Dardano A, Ratto A, Guastavino F, Tiemblo P. Electrical strength in ramp voltage AC tests of LDPE and its nanocomposites with silica and fibrous and laminar silicates. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/polb.21464] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Vaughan AS, Swingler SG, Zhang Y. Polyethylene Nanodielectrics: The Influence of Nanoclays on Structure Formation and Dielectric Breakdown. ACTA ACUST UNITED AC 2006. [DOI: 10.1541/ieejfms.126.1057] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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MacDonald AM, Vaughan AS, Wyeth P. On confocal Raman spectroscopy of semicrystalline polymers: the effect of optical scattering. APPLIED SPECTROSCOPY 2003; 57:1475-1481. [PMID: 14686768 DOI: 10.1366/000370203322640107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A series of semicrystalline polymers has been prepared through morphological control. Each of these has an identical refractive index but a different, well-defined, scattering behavior. From existing geometrical optical theories of confocal Raman spectroscopy, these materials should behave identically. Initially, the extent of scattering in each system was assessed quantitatively, from the near-infrared through the visible wavelength range, by UV/visible spectroscopy. The effect of optical scattering on the variation of intensity of the Raman scattered radiation with subsurface position was then examined in all four materials; the effect of surface roughness was also considered in the highest clarity system. Where surface effects are removed through careful sample preparation and the materials are interrogated using identical optical systems to mitigate against the impact of refractive index mismatch and other optical effects, the Raman response is strongly affected by the scattering characteristics of each material. A simple empirical relationship has been determined that adequately described all our specimens.
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Affiliation(s)
- A M MacDonald
- Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
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