Study of the effect of modification with small additives of phenylenediamines

2021 ◽  
pp. 26-34
Author(s):  
A.V. Filonovich ◽  
O.M. Gubanov ◽  
D.S. Alymov ◽  
V.N. Gadalov

The studies of the mechanical electrophysical properties of polymers and their modifications under the simultaneous influence of electrical discharges and mechanical force are presented. The paper presents the results of the experimental studies of the electrophysical and mechanical strength, the temperature dependence of the tangent of the dielectric loss angle, the specific volume electrical resistance and the relative deformation at break of new film polymer materials obtained on the basis of high-pressure polyethylene (LDPE) with a mixture of phenylenediamine additives OPD and PhI. The content of additives varied in the range of (0.03-0.5) wt%. The established increase in the electrophysical characteristics (increase in resistance to high electric field) of the LDPE film with the introduction of 0.1 wt% of chemical additives of PhI and with subsequent three-fold orientation extraction can be associated with a decrease in the concentration of charge carriers and their mobility, as well as an increase in the degree of crystallinity and packing density of polymer chains, which makes it difficult for ionization processes to occur at a given high electric field strength. It is shown that a decrease in the electrophysical characteristics of the studied polymer materials in the presence of tensile mechanical forces leads to the accumulation of bulk charges in them and the formation of submicrocracks.

Author(s):  
В.Д. Минаков ◽  
Р.Н. Голых ◽  
П.В. Петреков ◽  
В.Н. Хмелёв

Современное развитие машино-, приборостроения, медицины, транспорта, авиации и ракетно-космической техники определяется создаваемыми новыми конструкционными материалами с улучшенными механическими свойствами. Основная задача сегодняшнего дня – создание новых образцов материалов путем решения двух взаимоисключающих задач –одновременного обеспечения низкой удельной массы и высоких прочностных свойств материалов. Многообещающим и успешно развивающимся направлением решения этой задачи является создание и применение полимерных материалов, которые оказы-ваются более чем в 5 раз легче традиционных металлов и сплавов. Однако обеспечение необходимых прочностных свойств полимеров невозможно без модификации их физической структуры при помощи ультразвукового воздействия. Существующие способы модификации структуры, основанные на введении химических добавок, улучшая одни свойства материала, ухудшают другие свойства. Поэтому необходимо рассмотреть физические способы модификации структуры. На сегодняшний день одним из перспективных физических способов является ультразвуковое воздействие. В статье описаны результаты экспериментальных исследований по выявлению оптимальной интенсивности ультразвуковых колебаний, обеспечивающей максимальный КПД механодеструкции макромолекул. Выявленные оптимальные условия воздействия (по расстоянию между излучателем и отражателем) позволили обеспечить повышение прочности композита на 44 % по сравнению с неоптимальными условиями, при которых ультразвуковое диспергирование наполнителя повышает прочность на 30%. The modern development of machinery, instrumentation, medicine, transport, aviation and rocket and space technology is determined by the new construction materials created with improved mechanical properties. The main task of today is to create new samples of materials by solving two mutually exclusive tasks - simultaneously ensuring low specific gravity and high strength properties of materials. A promising and successfully developing direction for solving this problem is the creation and application of polymer materials that are more than 5 times lighter than traditional metals and alloys. However, it is impossible to ensure the necessary strength properties of polymers without modifying their physical structure with the help of ultrasonic action. Existing methods of modifying the structure based on the introduction of chemical additives, improving some properties of the material, worsen other properties. Therefore, it is necessary to consider physical ways of modifying the structure. To date, one of the promising physical methods is ultrasound exposure. The article describes the results of experimental studies to identify the optimal intensity of ultrasonic vibrations, providing maximum efficiency of mechanodestruction of macromolecules. The revealed optimal conditions of action (in terms of the distance between the radiator and the reflector) made it possible to increase the strength of the composite by 44% compared with non-optimal conditions under which ultrasonic dispersion of the filler increases the strength by 30%.


2020 ◽  
Vol 140 (8) ◽  
pp. 650-655
Author(s):  
Shoki Tsuji ◽  
Yoji Fujita ◽  
Hiroaki Urushibata ◽  
Akihiko Kono ◽  
Ryoichi Hanaoka ◽  
...  

2018 ◽  
Vol 7 (3.36) ◽  
pp. 127 ◽  
Author(s):  
Nishanthi Sunthrasakaran ◽  
Nor Akmal Mohd Jamail ◽  
Qamarul Ezani Kamarudin ◽  
Sujeetha Gunabalan

The most important aspect influencing the circumstance and characteristics of electrical discharges is the distribution of electric field in the gap of electrodes. The study of discharge performance requires details on the variation of maximum electric field around the electrode. In electrical power system, the insulation of high voltage power system usually subjected with high electric field. The high electric field causes the degradation performance of insulation and electrical breakdown start to occur. Generally, the standard sphere gaps widely used for protective device in electrical power equipment. This project is study about the electric field distribution and current density for different electrode configuration with XLPE barrier. Hence, the different electrode configuration influences the electric field distribution. This project mainly involves the simulation in order to evaluate the maximum electric field for different electrode configuration. Finite Element Method (FEM) software has been used in this project to perform the simulation. This project also discusses the breakdown characteristics of the XLPE. The accurate evaluation of electric field distribution and maximum electric field is an essential for the determination of discharge behavior of high voltage apparatus and components. The degree of uniformity is very low for pointed rod-plane when compared to other two electrode configurations. The non- uniform electric distribution creates electrical stress within the surface of dielectric barrier. As a conclusion, when the gap distance between the electrodes increase the electric field decrease.  


1979 ◽  
Vol 30 (2) ◽  
pp. 219-223 ◽  
Author(s):  
S.G. Dinev ◽  
Ch.I. Radev ◽  
K.V. Stamenov ◽  
K.A. Stankov

Author(s):  
Yingxia Wei ◽  
Yaoxiang Liu ◽  
Tie-Jun Wang ◽  
Na Chen ◽  
Jingjing Ju ◽  
...  

We report on a systematic experimental study on the fluorescence spectra produced from a femtosecond laser filament in air under a high electric field. The electric field alone was strong enough to create corona discharge (CD). Fluorescence spectra from neutral and ionic air molecules were measured and compared with pure high-voltage CD and pure laser filamentation (FIL). Among them, high electric field assisted laser FIL produced nitrogen fluorescence more efficiently than either pure CD or pure FIL processes. The nonlinear enhancement of fluorescence from the interaction of the laser filament and corona discharging electric field resulted in a more efficient ionization along the laser filament zone, which was confirmed by the spectroscopic measurement of both ionization-induced fluorescence and plasma-scattered 800 nm laser pulses. This is believed to be the key precursor process for filament-guided discharge.


1997 ◽  
Vol 72-74 ◽  
pp. 112-113 ◽  
Author(s):  
Zhidong Lou ◽  
Zheng Xu ◽  
Feng Teng ◽  
Xurong Xu

1998 ◽  
Vol 15 (1) ◽  
pp. 318 ◽  
Author(s):  
Robert Blum ◽  
Martin Sprave ◽  
Jurgen Sablotny ◽  
Manfred Eich

2013 ◽  
Vol 31 (16) ◽  
pp. 1960-1968 ◽  
Author(s):  
Ashutosh Singh ◽  
Gopu Raveendran Nair ◽  
Jamshid Rahimi ◽  
Yvan Gariepy ◽  
Vijaya Raghavan

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