The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Nobuhito Kamei - One of the best experts on this subject based on the ideXlab platform.
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Estimation of Electron Trap in Hydrocarbon-Based Thermosetting Resin / Fullerene Composite by Computational Science
2019 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 2019Co-Authors: Kotaro Ohzuno, Masahiro Kozako, Masayuki Hikita, Nobuhito KameiAbstract:The authors have reported that dielectric breakdown strength improves by 34% by uniformly dispersing 0.6 wt% fullerene in epoxy Resin. However, it is not easy to uniformly disperse fullerene in a polar epoxy Resin. On the other hand, hydrocarbon-based Thermosetting Resin (HTR: Hydrocarbon¬based Thermosetting Resin) has more excellent mechanical and electrical characteristics than epoxy Resin, and is almost nonpolar. Accordingly, HTR is expected to have high affinity with the nonpolar fullerene. In this paper, quantum chemistry calculations are performed on HTR/fullerene (C60) composites to estimate the electron trap depth from the electronic state density. As a result, it is found that the electron trap depth of the epoxy/fullerene composite and HTR/C60 are calculated as 3.0 and 3.7 eV, respectively. The increase in the electron trap depth suggests that the addition of fullerene to HTR can suppress acceleration of high energy electron leading to increase in the dielectric breakdown strength.
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Evaluation of Dielectric Strength of Tricyclopentadiene / Silica Microcomposites
2018 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 2018Co-Authors: Ysuske Okubo, Masahiro Kozako, Masayuki Hikita, Nobuhito KameiAbstract:Hydrocarbon-based Thermosetting Resins have properties such as low viscosity, low dielectric constant and high heat resistance as compared with epoxy Resins and are expected to be applied to electric devices in the future. However, hydrocarbon-based Thermosetting Resins have not been put into practice as an electrically insulating material yet. Therefore, it is necessary to understand the electrical characteristics. Generally, when organic polymeric material is used as an insulator for high voltage equipment, a large amount of loading of inorganic fillers is needed so as to decrease linear expansion coefficient. Therefore, it is crucial to investigate the effect of inorganic filler loading on the various properties such as mechanical, thermal, and electrical properties for higher voltage and longer term operation of high-voltage equipment. From the viewpoints, this paper deals with electrical insulation properties of the hydrocarbon-based Thermosetting Resin with loaded micro silica particles. As a result, breakdown strength of hydrocarbon-based Thermosetting Resin is equal or higher than that of the epoxy Resin. As a result, it can be said that the hydrocarbon-based Thermosetting Resin with lower viscosity and lower dielectric constant than the epoxy Resin is promising as an insulating material for the next generation high voltage equipment.
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evaluation on applicability to electrical insulating material of hydrocarbon based Thermosetting Resin
Electronics and Communications in Japan, 2017Co-Authors: Keisuke Yoshida, Masahiro Kozako, Shinji Ishibe, M Hikita, Nobuhito KameiAbstract:This paper deals with dielectric properties of hydrocarbon-based Thermosetting Resin to evaluate the applicability to electrical insulating materials. Moreover, higher withstand voltage, lower dielectric constant, and lower moisture absorption are required for the electrical insulating materials. One of the candidate polymer materials satisfying such demands is hydrocarbon-based Thermosetting Resin, that is, polydicyclopentadiene P-DCP and polytricyclopentadiene P-TCP. We measured the dielectric properties such as dielectric constant, dielectric loss, volume resistivity, and breakdown strength BDS, and other properties such as moisture absorption, viscosity, mechanical strength, glass transition temperature, and coefficient of linear expansion of those specimens. It was found from the results in particular that P-DCP and P-TCP have the lower dielectric constant and the lower moisture absorption as compared with epoxy Resin, while the volume resistivity and the BDS of P-DCP and P-TCP are not different to those of epoxy Resin. As a result, it is elucidated that two kinds of hydrocarbon-based Thermosetting Resin have a potential for application to an electrical insulating material.
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Permittivity estimation of hydrocarbon-based Thermosetting Resin using quantum chemical calculation
2017 International Symposium on Electrical Insulating Materials (ISEIM), 2017Co-Authors: Yuki Fuchi, Masahiro Kozako, Masayuki Hikita, Ryota Nakasako Yusuke Okubo, Nobuhito KameiAbstract:In recent years, development of computers and progress of calculation algorithms promote understanding of the various mechanisms of characteristics of electrical insulating materials using quantum chemical calculation. This paper deals with quantum chemical calculation of the relative permittivity εr of dicyclopentadiene and tricyclopentadiene Resins expected as the next generation electrical insulating materials based on density functional theory and Clausius-Mossotti's, Onsager's or Kirkwood's equation. As a result, estimated values of the relative permittivity are found to reasonably agree with experimental ones. In addition, we investigate the influence of the number of repeating units in the molecular structure on εr. As a result, it is found that the estimated εr is almost independent of the number of repeating units.
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Comparison of electrical insulation properties of hydrocarbon-based Thermosetting Resin and epoxy Resin
2016 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 2016Co-Authors: Yuki Fuchi, Keisuke Yoshida, Masahiro Kozako, Masayuki Hikita, Nobuhito KameiAbstract:This paper deals with electrical insulation properties of hydrocarbon-based Thermosetting Resin that is tricyclopentadiene Resin (TCP Resin)/dicyclopentadiene (DCP Resin) copolymer in comparison with those of conventional epoxy Resin. To meet the needs of high heat resistance and high-voltage resistance to electrical insulating material, electrical insulation properties of TCP/DCP copolymer sample are investigated in the temperature region up to 250°C. As a result, DC conductivity σdc of TCP/DCP copolymer is 3 orders of magnitude lower than that of the epoxy Resin. It was shown that TCP/DCP copolymer is a promising dielectric material having low electric conductivity and high heat resistance.
Shiyu Du - One of the best experts on this subject based on the ideXlab platform.
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Experimental study of monitoring and controlling of composite cure process in autoclave featured with fiber optic sensor
Journal of Materials Science and Technology, 2001Co-Authors: B. Zhang, D Wang, Z. Wu, Shiyu DuAbstract:With the aid of the latest fiber optic sensing technology, the parameters in the cure process of Thermosetting Resin-matrix composite, such as temperature, viscosity, void and residual stress, can be monitored entirely and efficiently. The experiment results of the viscosity measurement in the composite cure process in autoclave using fiber optic sensors are presented. Based on the sensed information, a computer program is utilized to control the cure process. With this technology, the cure process becomes more apparent and controllable, which will greatly improve the cured products and reduce the cost.
Gerard Franklyn Fernando - One of the best experts on this subject based on the ideXlab platform.
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Monitoring and modeling the diffusion profile in a Thermosetting Resin
Proceedings of SPIE, 2009Co-Authors: R.s. Mahendran, S. N. Kukureka, Rongsheng Chen, Gerard Franklyn FernandoAbstract:At the previous SPIE conference in San Diego (2008), the authors presented and compared a range of low-cost optical fibre sensors for monitoring the cross-linking process of a Thermosetting Resin. The same sensor was used subsequently to monitor and quantify the diffusion of water in the cross-linked polymer. The current paper presents recent data on the deployment of an array of low-cost fibre-optic sensors to monitor the water diffusion front. The data obtained from the sensors are compared with conventional gravimetric measurements and theoretical predictions for the diffusion profile for water ingress in a cross-linked epoxy/amine Resin system.
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Fiber-optic sensor design for chemical process and environmental monitoring
Optics and Lasers in Engineering, 2009Co-Authors: R.s. Mahendran, S. D. Pandita, S. N. Kukureka, Liangmin Wang, Venkata Rajanikanth Machavaram, Rong Chen, Gerard Franklyn FernandoAbstract:"Curing" is a term that is used to describe the cross-linking reactions in a Thermosetting Resin system. Advanced fiber-reinforced composites are being used increasingly in a number of industrial sectors including aerospace, marine, sport, automotive and civil engineering. There is a general realization that the processing conditions that are used to manufacture the composite can have a major influence on its hot-wet mechanical properties. This paper is concerned with the design and demonstration of a number of sensor designs for in situ monitoring of the cross-linking reactions of a commercially available Thermosetting Resin system. Simple fixtures were constructed to enable a pair of cleaved optical fibers with a defined gap between the end-faces to be held in position. The Resin system was introduced into this gap and the cure kinetics were followed by transmission infrared spectroscopy. A semi-empirical model was used to describe the cure process using the data obtained at different cure temperatures. The same sensor system was used to detect the ingress of moisture into the cured Resin system. (C) 2009 Elsevier Ltd. All rights reserved.
Shigeo Asai - One of the best experts on this subject based on the ideXlab platform.
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Quantitative analysis of the phase-separated structure and mechanical properties of acrylic copolymer/epoxy Thermosetting Resin composites
Polymer Journal, 2015Co-Authors: Isao Ichikawa, Toshio Sugizaki, Shuichi Akasaka, Shigeo AsaiAbstract:The effects of thermal curing reactivity on the phase-separated structures of acrylic copolymer/epoxy Thermosetting Resin composites containing various accelerator amounts were investigated to elucidate their phase separation behavior. These composites exhibited a sea-island structure, in which the island size decreased as the amount of accelerator increased. The island diameter distribution was represented as a lognormal plot. Island formation is explained by the law of proportionate effect. As observed during the last stage of phase separation via spinodal decomposition, small domains formed prior to coalescing. The effects of material composition on the phase structures and mechanical properties of acrylic copolymer/epoxy Thermosetting Resin composites were also examined. The morphologies varied depending on the components, and in particular, the total island area fractions and fracture surface shapes after the tensile tests differed. A small fraction of island area resulted in a lower fracture surface roughness and higher mechanical strength, indicating that in stronger composites, many epoxy components remained in the acrylic copolymer-rich sea phases. In addition, the destruction of Resin composites was propagated through phase boundaries because the network formation states of the sea and island phases do not significantly differ. The effects of thermal curing reactivity on phase-separated structures of acrylic copolymer/epoxy Thermosetting Resin composites were investigated to clarify their phase separation behavior. These composites displayed a sea-island structure, for which the island size altered as the amount of accelerator. The island diameter distribution was represented as a lognormal plot. This phase separation is explained by the law of proportionate effect as observed during the last stage of phase separation via spinodal decomposition.
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Quantitative analysis of the phase-separated structure and mechanical properties of acrylic copolymer/epoxy Thermosetting Resin composites
Polymer Journal, 2015Co-Authors: Isao Ichikawa, Toshio Sugizaki, Shuichi Akasaka, Shigeo AsaiAbstract:The effects of thermal curing reactivity on phase-separated structures of acrylic copolymer/epoxy Thermosetting Resin composites were investigated to clarify their phase separation behavior. These composites displayed a sea-island structure, for which the island size altered as the amount of accelerator. The island diameter distribution was represented as a lognormal plot. This phase separation is explained by the law of proportionate effect as observed during the last stage of phase separation via spinodal decomposition.
B. Zhang - One of the best experts on this subject based on the ideXlab platform.
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Experimental study of monitoring and controlling of composite cure process in autoclave featured with fiber optic sensor
Journal of Materials Science and Technology, 2001Co-Authors: B. Zhang, D Wang, Z. Wu, Shiyu DuAbstract:With the aid of the latest fiber optic sensing technology, the parameters in the cure process of Thermosetting Resin-matrix composite, such as temperature, viscosity, void and residual stress, can be monitored entirely and efficiently. The experiment results of the viscosity measurement in the composite cure process in autoclave using fiber optic sensors are presented. Based on the sensed information, a computer program is utilized to control the cure process. With this technology, the cure process becomes more apparent and controllable, which will greatly improve the cured products and reduce the cost.
