scholarly journals Study of dielectric properties of 4-methylstyrene and α-methylstyrene copolymer films with different molar ratio of initial monomers

2019 ◽  
Vol 58 (6) ◽  
pp. 55-58
Author(s):  
Ignat S. Dolgin ◽  
◽  
Pyotr P. Purygin ◽  
Yury P. Zarubin ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Methylene Chloride ◽  
Molar Ratio ◽  
Loss Angle ◽  
Electrical Capacitance ◽  
Copolymer Films ◽  
Laboratory Conditions ◽  
Dielectric Loss Angle ◽  
Material Sample

Two new copolymers of 4-methylstyrene and α-methylstyrene were obtained by the emulsion polymerization method according to the previously described and tested method in the course of the experiment in laboratory conditions. The molar ratio of the starting monomers of 4-methylstyrene and α-methylstyrene was 9: 2 and 10: 1, respectively, in each material sample. The structure of the copolymers obtained was confirmed by IR and 1H NMR spectroscopy. Under laboratory conditions, three prototypes of each copolymer film were obtained from the solution. A sample of the copolymer was dissolved in methylene chloride was applied on a smooth glass substrate. After complete evaporation of the solvent, the film was separated from the substrate. The thickness of the films for each copolymer sample was 20, 30, and 50 microns. In the course of further experimentation, these samples were examined for the values of dielectric constant and tangent of dielectric loss angle. The basis of this experiment used a resonant method of measurement. The presented method is based on the variation of conductivity due to a change in the electrical capacitance of the oscillating circuit. In this experiment, the magnitude of the electrical capacitance and the tangent of the dielectric loss angle were measured. Based on the value of the capacitance and the parameters of the film sample to be measured, it is possible to calculate the dielectric constant. From the data obtained it can be seen that with increasing film thickness, dielectric constant values decrease. However, the indicators of the tangent of dielectric loss angle increase. With an increase in the measurement frequency, a slight decrease in the dielectric constant is observed, and the value of the tangent of the dielectric loss angle decreases nonlinearly. In addition, it should be noted that the samples of 4-methylstyrene-α-methylstyrene copolymer films with a molar ratio of starting monomers of 10: 1 have a higher dielectric constant, along with lower values of the dielectric loss tangent. From this it follows that samples with a lower proportion of α-methylstyrene in their structure have better dielectric characteristics compared with their counterparts with a high content of α-methylstyrene.

Synthesis of new copolymers based on 2,3,4,5,6-pentafluorostyrene, styrene, α-methylstyrene and 4-fluoro-α-methylstyrene

2019 ◽  
Vol 60 (12) ◽  
pp. 91-95
Author(s):  
Ignat S. Dolgin ◽  
◽  
Pyotr P. Purygin ◽  
Yury P. Zarubin ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Elevated Temperatures ◽  
Methylene Chloride ◽  
Research Work ◽  
Molar Ratio ◽  
Methyl Styrene ◽  
Derivatives Of

At the first stages of the research work, a copolymer of styrene and α methyl styrene was synthesized by the method of radical emulsion polymerization in an inert atmosphere of argon. The initiator was ammonium persulfate. The molar ratio of the initial monomers of styrene and α-methylstyrene was 70 : 30, respectively. It was found that copolymers synthesized under special controlled conditions have good values of permittivity and dielectric loss tangent. It should be noted that the choice of emulsifier directly affects the values of these indicators. It was previously shown that the most optimal emulsifier is potassium stearate, using which the best values of the dielectric constant and dielectric loss tangent were achieved. At the second stage of the research work, a number of copolymers were synthesized containing 4-methoxystyrene, 4 methyl styrene and α-methyl styrene in their structure. It was experimentally confirmed that the synthesis procedure may be applicable for the preparation of copolymers based on derivatives of styrene and α-methylstyrene. The resulting series of copolymers is highly soluble in methylene chloride; films of each copolymer sample of different thicknesses were obtained by casting from a solution. For this series of copolymer films, the dielectric constant and dielectric loss tangent were determined. It was found that the best values of permittivity and dielectric loss tangent are possessed by a sample of copolymer 4-methoxystyrene and α-methylstyrene. At the latest stage of the study, copolymers of styrene and 2,3,4,5,6-pentafluorostyrene, α-methylstyrene and 4-fluoro-α-methylstyrene, 2,3,4,5,6-pentafluorostyrene and 4-fluoro-α-methylstyrene were synthesized. These fluorine-containing derivatives of styrene and α-methylstyrene easily enough enter into the reaction of radical emulsion copolymerization. The copolymer yields are 53-76%, calculated on the weight of the starting monomers. The structure of a number of newly synthesized copolymers was confirmed by IR spectroscopy. In the future, it is planned to define the values of dielectric constant and dielectric loss tangent for these copolymer samples. It is planned to study the thermomechanical properties of the samples, since fluorine-containing polymers are a promising material for operation at elevated temperatures.

scholarly journals Effects of additional amount of carbon micro-coils on the dielectric properties of its composite sheet

2014 ◽  
Vol 38 (1) ◽  
pp. 39-47
Author(s):  
Meherun Nessa
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Relative Dielectric Constant ◽  
Loss Angle ◽  
Composite Sheet ◽  
Dielectric Parameters ◽  
Dielectric Loss Angle ◽  
Additional Amount ◽  
Academy Of Sciences

The morphology and dielectric properties of carbon micro-coils (CMC) composite sheet wereexamined. Frequency dependence of dielectric parameters; dielectric loss angle (?), dielectric losstangent (tan?) and relative dielectric constant ( ?r) were measured on single and double-helixcomposite sheet. It was found that these parameters of CMC/polysilicone composites extensivelychanged with the additional amount of CMC with polysilicone resine. It was also observed that thehigher additional amount (wt%) of CMC is appropriate for high response. DOI: http://dx.doi.org/10.3329/jbas.v38i1.20210 Journal of Bangladesh Academy of Sciences, Vol. 38, No. 1, 39-47, 2014

scholarly journals Synthesis of constructive-technological decisions of regulation of working capacitance of cables of industrial networks

2021 ◽  
pp. 44-49
Author(s):  
G.V. Bezprozvannych ◽  
I.A. Kostiukov ◽  
O.A. Pushkar
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Effective Dielectric Constant ◽  
Protective Film ◽  
Loss Angle ◽  
Twisted Pair ◽  
Industrial Networks ◽  
The Past ◽  
Dielectric Loss Angle ◽  
Physical Level

Introduction. Over the past 10 years, the number of industrial networks has more than doubled. At the physical level, all industrial technology networks are based on twisted pair. Purpose. Synthesis of constructive-technological decisions of regulation of electric capacitance of the insulated conductor at a stage of manufacturing of twisted pair of cables of industrial networks. Methodology. The method of secondary charges to determine the capacitance of the insulated conductor by varying the thickness of the solid and foamed polyethylene insulation. Practical value. Effective regulation is provided on the basis of the obtained dependencies of the effective dielectric constant, the tangent of the dielectric loss angle and the capacitance of the insulated conductor on the degree of foaming and the thickness of the protective film of two-layer insulation. At a degree of porosity of 40 %, the dielectric constant decreases by 25 %, the tangent of the dielectric loss angle – by 33 %, the electrical capacitance of the insulated conductor – by 20 %.

Measurements of the dielectric constant and dielectric-loss angle of industrial water

1969 ◽  
Vol 12 (2) ◽  
pp. 231-231
Author(s):  
A. A. Vorob'ev ◽  
M. P. Tonkonogov ◽  
V. A. Veksler
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Industrial Water ◽  
Loss Angle ◽  
Dielectric Loss Angle

scholarly journals Dielectric properties of bionano-composites modified by fish scales

2021 ◽  
Vol 9 (2) ◽  
pp. 043-046
Author(s):  
Gojayev EM ◽  
Salimova VV
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Fish Scales ◽  
Loss Angle ◽  
Dielectric Loss Angle ◽  
Temperature Dependences ◽  
Volumetric Content

The presented work presents the results of studying the temperature dependences of the dielectric constant and the tangent of the dielectric loss angle of biocomposites modified with fish scales. It was found that with an increase in the volumetric content of the bio-filler, the dielectric constant of the biocomposites increases, and the tangent of the dielectric loss angle decreases. By varying the volumetric content of the bio-filler, it is possible to control the properties of biocomposites in the desired direction.

Sparse Representation Based Dielectric Loss Angle Measurement

2015 ◽  
Vol 9 (1) ◽  
pp. 566-570
Author(s):  
Zhang Ji ◽  
Jianfeng Zheng
Keyword(s):  
Dielectric Loss ◽  
Power Systems ◽  
Sparse Representation ◽  
Precise Measurement ◽  
Angle Measurement ◽  
Measuring Error ◽  
Loss Angle ◽  
Analysis Method ◽  
Electric Capacity ◽  
Dielectric Loss Angle

Precise measurement of dielectric loss angle is very important for electric capacity equipment in recent power systems. When signal-to-noise is low and fundamental frequency is fluctuating, aiming at the measuring error of dielectric loss angle based on some recent Fourier transform and wavelet transform harmonics analysis method, we propose a novel algorithm based on sparse representation, and improved it to be more flexible for signal sampling. Comparison experiments describe the advantages of our method.

Nondestructive method of measurement of laminated plates dielectric parameters

Antennas ◽  
2021 ◽  
Author(s):  
Yu. G. Belov ◽  
V. V. Biryukov ◽  
I. A. Egorov
Keyword(s):  
Dielectric Loss ◽  
Relative Permittivity ◽  
Metal Foil ◽  
Q Factor ◽  
Loss Angle ◽  
Plate Material ◽  
Dielectric Plate ◽  
Electrodynamic Model ◽  
Dielectric Loss Angle ◽  
Electromagnetic Oscillations

The methods for measuring the parameters of dielectric materials of foil plates have been considered. It has been shown that for “non-destructive measurements” (i.e., without removing the metal foil from the dielectric plate), a method based on the excitation of electromagnetic oscillations in a rectangular plate considered as a resonator can be used. Based on the results of measurements of their resonant frequencies and Q-factors, the relative permittivity and the tangent of the dielectric loss angle of the material can be determined. The calculated relations obtained by the authors of the article in one of the early works using the electrodynamic model of a resonator with “magnetic walls” at the ends have been presented. The Q-factor of the resonator has been calculated by the perturbation method, taking into account the losses in the plate dielectric and metallization layers. The results of measurements for four samples from different dielectrics in the frequency range 200...1000 MHz have been presented. The experimental method has been described, in particular, the method of identifying the type of oscillation, the procedure for processing the measurement results. Due to the high sensitivity of the vector analyzer, measurements have been made with a possible small connection of the resonator (metallized plate) with the measuring circuit. This made it possible to minimize the influence of the coupling elements on the measured Qfactor of the oscillations and to consider this Q-factor close to its own. The presented results are in good agreement with the reference data for the materials. The conducted studies have shown the possibility of using a resonator model with “magnetic walls” at the ends for the analysis of electromagnetic oscillations in a foil dielectric plate and, accordingly, using the relations obtained in this case to determine the parameters of the dielectric plate. The conditions for using this model are the small thickness of the plate in comparison with its transverse dimensions and relatively low operating frequencies. The method, which is based on the calculated ratios of the electrodynamic model of the resonator with “magnetic” walls at the ends, provides a sufficiently high accuracy of determining the relative permittivity of the plate material, which led to the use of it (the method) in practice to control the parameters of foil dielectric plates intended for the manufacture of microwave and UHF-band microcircuits. The studies, the results of which have been presented in this paper, allow us to conclude that this method can also be recommended for determining the tangent of the dielectric loss angle of the plate material.

The molecular mobility of the epoxy binder in a modified composites by electric-hammer

2021 ◽  
Vol 103 (3) ◽  
pp. 70-78
Author(s):  
Petro Stukhlyak ◽  
Oleg Totosko
Keyword(s):  
Composite Materials ◽  
Dielectric Loss ◽  
Molecular Mobility ◽  
Loss Angle ◽  
Hydraulic Shock ◽  
Surface Layers ◽  
Dielectric Characteristics ◽  
Dielectric Loss Angle ◽  
Dispersed Filler ◽  
Electric Hammer

In this work, the study of molecular mobility in the surface layers by the method of determining the dielectric characteristics of materials modified by electrospark hydraulic shock, determined the optimal content of the dispersed filler. Comparative data of the tangent of the dielectric loss angle of treated and untreated composite materials are presented.

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