Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995884
M. Mansor, A. Ghani, P. Ghosh
Partial discharge (PD) is identified as a main factor contributing to the insulation deterioration in HV equipment including underground cable. This is the first time an attempt has been made to investigate the effect of soil thermal resistivity on PD activities in underground power cables. In this paper, a detailed experiment has been carried out on a simulated set up to study the effect of various soil conditions on the level of PD in an 11 kV, single core, 240 mm /sup 2/ XLPE cable. The PD parameters are measured with the help of Haefely Trench TE 571, PD measurement system using straight detection method. PD patterns obtained in the form of elliptical waveform are then analysed using statistical techniques. In this paper, the statistical pattern recognition technique has been successfully applied to classify the PD patterns obtained from the experiment under different soil conditions. Thus, classification of PD patterns aims at the recognition of discharges from a particular soil condition. This information is vital for estimating the harmful effect of the thermal property of soil on the level of PD and can lead to decision making like reconditioning of backfill material and adjustment in cable loading.
局部放电是导致包括地下电缆在内的高压设备绝缘劣化的主要因素。这是首次尝试研究土壤热电阻率对地下电力电缆中PD活动的影响。本文在模拟装置上进行了详细的试验，研究了不同土壤条件对11 kV单芯240 mm /sup 2/ XLPE电缆中PD水平的影响。PD参数的测量采用Haefely Trench TE 571, PD测量系统采用直线检测法。然后利用统计技术对椭圆波形形式的局部放电模式进行分析。本文成功地应用统计模式识别技术对不同土壤条件下试验得到的PD模式进行了分类。因此，PD模式的分类旨在识别特定土壤条件下的排放。这些信息对于估计土壤热特性对PD水平的有害影响至关重要，并可导致诸如回填材料修复和电缆加载调整等决策。
{"title":"Classification of PD patterns in XLPE cables under various soil conditions using statistical technique","authors":"M. Mansor, A. Ghani, P. Ghosh","doi":"10.1109/ELINSL.2002.995884","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995884","url":null,"abstract":"Partial discharge (PD) is identified as a main factor contributing to the insulation deterioration in HV equipment including underground cable. This is the first time an attempt has been made to investigate the effect of soil thermal resistivity on PD activities in underground power cables. In this paper, a detailed experiment has been carried out on a simulated set up to study the effect of various soil conditions on the level of PD in an 11 kV, single core, 240 mm /sup 2/ XLPE cable. The PD parameters are measured with the help of Haefely Trench TE 571, PD measurement system using straight detection method. PD patterns obtained in the form of elliptical waveform are then analysed using statistical techniques. In this paper, the statistical pattern recognition technique has been successfully applied to classify the PD patterns obtained from the experiment under different soil conditions. Thus, classification of PD patterns aims at the recognition of discharges from a particular soil condition. This information is vital for estimating the harmful effect of the thermal property of soil on the level of PD and can lead to decision making like reconditioning of backfill material and adjustment in cable loading.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"63 1","pages":"74-78"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84688225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995977
T. Shimakage, K. Wu, T. Kato, T. Okamoto, Y. Suzuoki
Usually, the lifetime of electric power apparatus is assumed as the period with low failure probability. In this paper the power cable with water-tree degradation, for which available data are relatively rich; was studied as an example to discuss the economically optimum replacement time of the power apparatuses. From the accelerating-degradation test, the growth rate of maximum water-tree length was calculated. Then the annual failure probability of the cable was computed by using the Weibull distribution plot of breakdown voltage for the cables with different maximum water-tree length. The total cost is a function of the replacement time or the estimated lifetime and the ratio of the average loss by one failure to the replacement expense. The optimized replacement time which corresponded to the minimum total cost was evaluated under different practical conditions.
{"title":"Economic evaluation of cable replacement considering annual failure probability","authors":"T. Shimakage, K. Wu, T. Kato, T. Okamoto, Y. Suzuoki","doi":"10.1109/ELINSL.2002.995977","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995977","url":null,"abstract":"Usually, the lifetime of electric power apparatus is assumed as the period with low failure probability. In this paper the power cable with water-tree degradation, for which available data are relatively rich; was studied as an example to discuss the economically optimum replacement time of the power apparatuses. From the accelerating-degradation test, the growth rate of maximum water-tree length was calculated. Then the annual failure probability of the cable was computed by using the Weibull distribution plot of breakdown voltage for the cables with different maximum water-tree length. The total cost is a function of the replacement time or the estimated lifetime and the ratio of the average loss by one failure to the replacement expense. The optimized replacement time which corresponded to the minimum total cost was evaluated under different practical conditions.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"84 1","pages":"472-475"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83849242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995930
M. Uğur, A. Kuntman
Surface tracking on organic solid insulators is one of the main reasons for failure in high voltage (HV) systems. Due to various factors, such as humidity, pollution, ice load, increase in local voltage, etc., it is hard to make an estimation about the life of an insulator. For many years Weibull statistics have been widely used and accepted as a successful mathematical method to predict the remaining lifetime of an insulating material. The basic reliability function R(t) = e/sup (-/spl lambda/tm)/, where '/spl lambda/' is the scale and 'm' is the shape parameter, can perform well for certain conditions, however it might be insufficient in lifetime prediction in multi-variable conditions. In this research several tests have been performed according to IEC 587 Inclined Plane Test method to investigate the breakdown times of polymeric insulation materials under various external conditions generated artificially in laboratory. These factors seemed to reduce the lifetime of insulating materials up to 50-70 percent. A model based on Weibull statistics has been proposed for estimating the breakdown time of polymeric insulation material. By using appropriate parameters this improved model can make successful estimates within a reasonable accuracy in varying external conditions such as tensile stress or increased surface hydrophobicity, etc.
{"title":"Investigation of the ageing process in polymeric insulators by using improved Weibull statistics","authors":"M. Uğur, A. Kuntman","doi":"10.1109/ELINSL.2002.995930","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995930","url":null,"abstract":"Surface tracking on organic solid insulators is one of the main reasons for failure in high voltage (HV) systems. Due to various factors, such as humidity, pollution, ice load, increase in local voltage, etc., it is hard to make an estimation about the life of an insulator. For many years Weibull statistics have been widely used and accepted as a successful mathematical method to predict the remaining lifetime of an insulating material. The basic reliability function R(t) = e/sup (-/spl lambda/tm)/, where '/spl lambda/' is the scale and 'm' is the shape parameter, can perform well for certain conditions, however it might be insufficient in lifetime prediction in multi-variable conditions. In this research several tests have been performed according to IEC 587 Inclined Plane Test method to investigate the breakdown times of polymeric insulation materials under various external conditions generated artificially in laboratory. These factors seemed to reduce the lifetime of insulating materials up to 50-70 percent. A model based on Weibull statistics has been proposed for estimating the breakdown time of polymeric insulation material. By using appropriate parameters this improved model can make successful estimates within a reasonable accuracy in varying external conditions such as tensile stress or increased surface hydrophobicity, etc.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"28 1","pages":"275-279"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81885664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995926
J. Goudie
This paper reviews outdoor insulator contamination problems and presents the variety of silicone based maintenance solutions from a historical perspective, from early silicone greases to the latest RTV elastomer products. Results of a current study on commercially available RTV coatings is compared in terms of specifications, actual uncured and cured physical properties, and results of electrical performance evaluations are presented. An attempt is made to attribute observed differences in performance to the levels and types of formulation components and how these may affect installation and performance in-use of these coatings.
{"title":"Silicones for outdoor insulator maintenance","authors":"J. Goudie","doi":"10.1109/ELINSL.2002.995926","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995926","url":null,"abstract":"This paper reviews outdoor insulator contamination problems and presents the variety of silicone based maintenance solutions from a historical perspective, from early silicone greases to the latest RTV elastomer products. Results of a current study on commercially available RTV coatings is compared in terms of specifications, actual uncured and cured physical properties, and results of electrical performance evaluations are presented. An attempt is made to attribute observed differences in performance to the levels and types of formulation components and how these may affect installation and performance in-use of these coatings.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"34 1","pages":"256-259"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87794883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995935
A. Helgeson, M. Zahn
The Kerr electro-optic field mapping technique has been used to study space charge effects in high voltage pulsed propylene carbonate (C/sub 4/H/sub 6/O/sub 3/) using stainless steel parallel-plate electrodes. Measurements presented here were taken using a circular polariscope with aligned polarizers at room temperature (T/spl sim/20/spl deg/C) with average initial electric field strengths of E/sub 0//spl sim/52 kV/cm and for measurement times ranging from 10 /spl mu/s to 1 ms. The light intensity pictures were analyzed along a line in the center of the electrode gap. From the light intensity distribution the electric field and space charge were calculated as a function of position and time. The calculated space charge distributions show both positive and negative charge injections from the electrodes as well as bulk charge dissociation.
{"title":"Kerr electro-optic measurements of space charge effects in high voltage pulsed propylene carbonate using parallel-plate electrodes","authors":"A. Helgeson, M. Zahn","doi":"10.1109/ELINSL.2002.995935","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995935","url":null,"abstract":"The Kerr electro-optic field mapping technique has been used to study space charge effects in high voltage pulsed propylene carbonate (C/sub 4/H/sub 6/O/sub 3/) using stainless steel parallel-plate electrodes. Measurements presented here were taken using a circular polariscope with aligned polarizers at room temperature (T/spl sim/20/spl deg/C) with average initial electric field strengths of E/sub 0//spl sim/52 kV/cm and for measurement times ranging from 10 /spl mu/s to 1 ms. The light intensity pictures were analyzed along a line in the center of the electrode gap. From the light intensity distribution the electric field and space charge were calculated as a function of position and time. The calculated space charge distributions show both positive and negative charge injections from the electrodes as well as bulk charge dissociation.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"47 1","pages":"298-301"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89157002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995929
L. Meyer, R. Omranipour, S. Jayaram, E. Cherney
In this work, the influence of particle size and concentration of fillers used in silicone rubber compounds for outdoor insulation is investigated. Alumina tri-hydrate and silica with mean particle sizes of 5 and 10 /spl mu/m are used as fillers with concentrations of 10, 30 and 50% by weight in a two-part room temperature vulcanized silicone rubber base polymer. The results from inclined plane tests show that samples with high concentrations of filler and/or smaller particle size have better tracking and erosion resistance than samples with lower concentration and/or larger particle size.
{"title":"The effect of ATH and silica on tracking and erosion resistance of silicone rubber compounds for outdoor insulation","authors":"L. Meyer, R. Omranipour, S. Jayaram, E. Cherney","doi":"10.1109/ELINSL.2002.995929","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995929","url":null,"abstract":"In this work, the influence of particle size and concentration of fillers used in silicone rubber compounds for outdoor insulation is investigated. Alumina tri-hydrate and silica with mean particle sizes of 5 and 10 /spl mu/m are used as fillers with concentrations of 10, 30 and 50% by weight in a two-part room temperature vulcanized silicone rubber base polymer. The results from inclined plane tests show that samples with high concentrations of filler and/or smaller particle size have better tracking and erosion resistance than samples with lower concentration and/or larger particle size.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"96 1","pages":"271-274"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74365699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995902
J. van Bolhuis, E. Gulski, J. Smit
Because the energy market liberalisation forces utilities to cut costs, delayed replacement and smaller maintenance budgets have become goals for many utilities. Competing with this demand is the increased risk of liability for unexpected nondelivered energy. These two forces have stimulated research into the field of onsite and online diagnosis in order to determine the condition of a transformer at the least possible cost. One of the fields that has attracted attention is partial discharge measurements, as they are seen as a good indicator for local defects and incipient failure caused by such. This paper describes two onsite partial discharge methods that both use frequency information to to deal with noise and enable online measurements. One method uses VHF frequencies, the other uses UHF frequencies. Based on this comparison, a questionnaire was sent to several Dutch utilities asking them to specify how the see the relevance of partial discharge measurements and how they would implement it. The paper presents the conclusions from this questionnaire and the direction of development desired by the utilities.
{"title":"On-line PD detection, requirements for practical use","authors":"J. van Bolhuis, E. Gulski, J. Smit","doi":"10.1109/ELINSL.2002.995902","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995902","url":null,"abstract":"Because the energy market liberalisation forces utilities to cut costs, delayed replacement and smaller maintenance budgets have become goals for many utilities. Competing with this demand is the increased risk of liability for unexpected nondelivered energy. These two forces have stimulated research into the field of onsite and online diagnosis in order to determine the condition of a transformer at the least possible cost. One of the fields that has attracted attention is partial discharge measurements, as they are seen as a good indicator for local defects and incipient failure caused by such. This paper describes two onsite partial discharge methods that both use frequency information to to deal with noise and enable online measurements. One method uses VHF frequencies, the other uses UHF frequencies. Based on this comparison, a questionnaire was sent to several Dutch utilities asking them to specify how the see the relevance of partial discharge measurements and how they would implement it. The paper presents the conclusions from this questionnaire and the direction of development desired by the utilities.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"20 1","pages":"158-161"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73002059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995897
M. Stranges, J. Dymond, M. Aurnou
The investigation of failure mechanisms in stator coils is considered an art and can consume a significant amount of time and valuable resources. The authors have applied rigorous experimental methodology and statistical principles in the investigation of hi-pot failures, analysis of voltage endurance test results and other insulation projects. Application of statistical tools has been found to increase the efficiency of the work and increase confidence in the conclusions. This paper discusses the investigative methods using examples such as failure modes and effects analysis, hypothesis testing, design of experiments and analysis of variance. The discovery of potential areas of process improvement based on voltage endurance testing of one insulation system is discussed.
{"title":"Application of statistical tools to the investigation of coil failures","authors":"M. Stranges, J. Dymond, M. Aurnou","doi":"10.1109/ELINSL.2002.995897","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995897","url":null,"abstract":"The investigation of failure mechanisms in stator coils is considered an art and can consume a significant amount of time and valuable resources. The authors have applied rigorous experimental methodology and statistical principles in the investigation of hi-pot failures, analysis of voltage endurance test results and other insulation projects. Application of statistical tools has been found to increase the efficiency of the work and increase confidence in the conclusions. This paper discusses the investigative methods using examples such as failure modes and effects analysis, hypothesis testing, design of experiments and analysis of variance. The discovery of potential areas of process improvement based on voltage endurance testing of one insulation system is discussed.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"66 1","pages":"131-136"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79786353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995964
S. Stangherlin, G. Salge, F. Koenig
The discharge phenomena were investigated in a background uniform field (plate - needle to plate arrangement) varying the needle protrusion (length=3 to 5 mm; tip radius= 200 /spl mu/m), the gas pressure (300 and 500 kPa) as well as the gas mixture composition (100%SF/sub 6/, 10%SF/sub 6/-90%N/sub 2/, 100%N/sub 2/). A positive polarity, low damped, fast oscillating (1.2 MHz), high voltage impulse (up to 450 kV peak) was applied to stress the test gap. The V-t characteristics in the mixture (breakdown voltage vs. time to breakdown) is reported and then compared to both the same curve of pure gases and similar measures available in literature. The discharge mechanism in the mixture is described and compared to the pure gases through voltage (capacitive sensor), discharge current (Rogowski coil), emitted light (photo-multiplier tube) and pictures from an image converter operating in both streak and frame modes.
{"title":"On the discharge phenomena in the 10%SF/sub 6/-90%N/sub 2/ gas mixture under fast oscillating impulse conditions","authors":"S. Stangherlin, G. Salge, F. Koenig","doi":"10.1109/ELINSL.2002.995964","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995964","url":null,"abstract":"The discharge phenomena were investigated in a background uniform field (plate - needle to plate arrangement) varying the needle protrusion (length=3 to 5 mm; tip radius= 200 /spl mu/m), the gas pressure (300 and 500 kPa) as well as the gas mixture composition (100%SF/sub 6/, 10%SF/sub 6/-90%N/sub 2/, 100%N/sub 2/). A positive polarity, low damped, fast oscillating (1.2 MHz), high voltage impulse (up to 450 kV peak) was applied to stress the test gap. The V-t characteristics in the mixture (breakdown voltage vs. time to breakdown) is reported and then compared to both the same curve of pure gases and similar measures available in literature. The discharge mechanism in the mixture is described and compared to the pure gases through voltage (capacitive sensor), discharge current (Rogowski coil), emitted light (photo-multiplier tube) and pictures from an image converter operating in both streak and frame modes.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"4 1","pages":"417-420"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78294801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-07DOI: 10.1109/ELINSL.2002.995955
T. Imai, Y. Hirano, H. Hirai, S. Kojima, T. Shimizu
Epoxy-silicate nanocomposites were prepared by dispersing synthetic layered silicates modified with alkylammonium ions. In the dispersing process, the organically modified layered silicates were mixed in epoxy resin with shearing, and aggregations of the silicates were removed by centrifugal separation after mixing epoxy resin and silicates. Micrographs taken by transmission electron microscopy (TEM) indicate that the nanocomposites have a mixed morphology including both parallel silicate layers (0.1-0.5 /spl mu/m, 5-15 layers) and exfoliated silicate layers (nano-scale dispersion) area. In terms of thermal resistance properties, the glass transition temperature (T/sub g/) of the nanocomposite was shifted to a higher temperature (/spl Delta/20/spl deg/C) than pure epoxy. Furthermore, dispersion of modified silicate prevented relative permittivity (/spl epsiv//sub r/) and dielectric loss (tan/spl delta/) from increasing at a high temperature above the glass transition temperature.
{"title":"Preparation and properties of epoxy-organically modified layered silicate nanocomposites","authors":"T. Imai, Y. Hirano, H. Hirai, S. Kojima, T. Shimizu","doi":"10.1109/ELINSL.2002.995955","DOIUrl":"https://doi.org/10.1109/ELINSL.2002.995955","url":null,"abstract":"Epoxy-silicate nanocomposites were prepared by dispersing synthetic layered silicates modified with alkylammonium ions. In the dispersing process, the organically modified layered silicates were mixed in epoxy resin with shearing, and aggregations of the silicates were removed by centrifugal separation after mixing epoxy resin and silicates. Micrographs taken by transmission electron microscopy (TEM) indicate that the nanocomposites have a mixed morphology including both parallel silicate layers (0.1-0.5 /spl mu/m, 5-15 layers) and exfoliated silicate layers (nano-scale dispersion) area. In terms of thermal resistance properties, the glass transition temperature (T/sub g/) of the nanocomposite was shifted to a higher temperature (/spl Delta/20/spl deg/C) than pure epoxy. Furthermore, dispersion of modified silicate prevented relative permittivity (/spl epsiv//sub r/) and dielectric loss (tan/spl delta/) from increasing at a high temperature above the glass transition temperature.","PeriodicalId":10532,"journal":{"name":"Conference Record of the the 2002 IEEE International Symposium on Electrical Insulation (Cat. No.02CH37316)","volume":"240 1","pages":"379-383"},"PeriodicalIF":0.0,"publicationDate":"2002-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77171432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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