Electrical properties dielectric constant

Electrical properties — dielectric constant (e), representing polarization dissipation factor (tan 8), representing relaxation phenomena dielectric strength (EB), representing breakdown phenomena and resistivity (pv), an inverse of conductivity — are compared with other polymers in Table 5.14.74 The low dielectric loss and high electrical resistivity coupled with low water absorption and retention of these properties in harsh environments are major advantages of fluorosilicone elastomers over other polymeric materials.74... 

Excellent, isotropic electrical properties. Dielectric constants of 2.4 to 2.6 have been demonstrated. Low dielectric constant is crucial as interconnect density increases. As space between conducting lines shrinks, inductance and cross-talk become problematic, but can be mitigated with lower dielectric constant materials. Polyimides, which are used extensively in the industry, exhibit anisotropic electrical properties in-plane dielectric constant can be as high as 4 while out of plane dielectric constant is generally above 3. 

Water absorption (24 h, 23°C) Electrical properties Dielectric constant (1 MHz) D150 ... 

FIG. 33 Dependencies of electrical properties dielectric constant (a) and dissipation factor (b) on irradiation aging measured at various frequencies (accelerated electrons dose 10 MGy dose rate 3 kGy/h). (Adapted from Ref. 67.) Column 1 1 kHz, nonirradiated materials column 2 1 kHz, irradiated materials column 3 1 MHz, nonirradiated materials column 4 1 MHz, irradiated materials. 

Additives antioxidant, mold release agent, plasticizer Adsorbent chemically or physically attached Electrical Properties dielectric constant, electrical... 

Electrical properties Dielectric strength Dielectric constant 60 Hz 10 Hz 10 Hz... 

The liquid-liquid interface is not only a boundary plane dividing two immiscible liquid phases, but also a nanoscaled, very thin liquid layer where properties such as cohesive energy, density, electrical potential, dielectric constant, and viscosity are drastically changed along with the axis from one phase to another. The interfacial region was anticipated to cause various specific chemical phenomena not found in bulk liquid phases. The chemical reactions at liquid-liquid interfaces have traditionally been less understood than those at liquid-solid or gas-liquid interfaces, much less than the bulk phases. These circumstances were mainly due to the lack of experimental methods which could measure the amount of adsorbed chemical species and the rate of chemical reaction at the interface [1,2]. Several experimental methods have recently been invented in the field of solvent extraction [3], which have made a significant breakthrough in the study of interfacial reactions. 

Thus, we see the initial connection between optical properties and the electrical and magnetic properties from the two previous sections. Substimtion of Eqs. (6.78) and (6.79) into (6.77) shows that the refractive index can be expressed in terms of the relative electric permittivity (dielectric constant), (cf. Table 6.5), and relative magnetic permeability of the medium, (1 - - x) [cf. Eq. (6.63)], where x is the magnetic susceptibility ... 

To consider the application of microwave irradiation for organic synthesis, the first step is to analyze the reaction components together with their dielectric properties among which of the greatest importance is dielectric constant (cr) sometimes called electric permeability. Dielectric constant (er) is defined as the ratio of the electric permeability of the material to the electric permeability of free space (i.e., vacuum) and its value can derived from a simplified capacitor model (Fig. 1.4). 

The impedance for the study of materials and electrochemical processes is of major importance. In principle, each property or external parameter that has an influence on the electrical conductivity of an electrochemical system can be studied by measurement of the impedance. The measured data can provide information for a pure phase, such as electrical conductivity, dielectrical constant or mobility of equilibrium concentration of charge carriers. In addition, parameters related to properties of the interface of a system can be studied in this way heterogeneous electron-transfer constants between ion and electron conductors, or capacity of the electrical double layer. In particular, measurement of the impedance is useful in those systems that cannot be studied with DC methods, e.g. because of the presence of a poor conductive surface coating. 

The liquid-liquid interface formed between two immissible liquids is an extremely thin mixed-liquid state with about one nanometer thickness, in which the properties such as cohesive energy density, electrical potential, dielectric constant, and viscosity are drastically changing from those of bulk phases. Solute molecules adsorbed at the interface can behave like a 2D gas, liquid, or solid depending on the interfacial pressure, or interfacial concentration. But microscopically, the interfacial molecules exhibit local inhomogeneity. Therefore, various specific chemical phenomena, which are rarely observed in bulk liquid phases, can be observed at liquid-liquid interfaces [1-3]. However, the nature of the liquid-liquid interface and its chemical function are still less understood. These situations are mainly due to the lack of experimental methods required for the determination of the chemical species adsorbed at the interface and for the measurement of chemical reaction rates at the interface [4,5]. Recently, some new methods were invented in our laboratory [6], which brought a breakthrough in the study of interfacial reactions. 

Examples of such properties are conductivity, refractive index, electrical moment, dielectric constant, chelate formation, ion dissociation, phase transitions, solubility, and viscosity. Certain physical changes that occur when the photochromic entity is chemically attached to the macromolecular backbone of polymers are of special interest (see Chapter 1, Volume 2). 

Polysulfone is UL listed for continuous service at 320F, although it will withstand higher temperatures intermittently. It offers a good combination of electrical properties dielectric strength and volume resistivities are high, while dielectric constant and dissipation factor are low. 

Closed-form expressions from composite theory are also useful in correlating and predicting the transport properties (dielectric constant, electrical conductivity, magnetic susceptibility, thermal conductivity, gas diffusivity and gas permeability) of multiphase materials. The models lor these properties often utilize mathematical treatments [54,55] which are similar to those used for the thermoelastic properties, once the appropriate mathematical analogies [56,57] are made. Such analogies and the resulting composite models have been pursued quite extensively for both particulate-reinforced and fiber-reinforced composites where the filler phase consists of discrete entities dispersed within a continuous polymeric matrix. 

Electrical properties of polymers that are subject to low electric field strengths can be described by their electrical conductivity, dielectric constant, dissipation factor, and triboelectric behavior. Materials can be classified as a function of their conductivity (k) in (Q/cm)- as follows conductors, O-IO" dissipatives, and insulators, lO or lower. Plastics are considered nonconductive materials (if the newly developed conducting plastics are not included). The relative dielectric constant of insulating materials (s) is the ratio of the capacities of a parallel plate condenser with and without the material between the plates. A correlation between the dielectric constant and the solubility parameter (6) is given by 6 7.0s. There is also a relation between resistivity R (the inverse of conductivity) and the dielectric constant at 298 K log R = 23 - 2s. 

Electrical Properties Dielectric Thermal Analysis Thermally Stimulated Current DEA TSC Dielectric Constant/ Dielectric Loss measured Current... 

Electrical properties Electrical resistivity Dielectric constant... 

Electrical Properties Dielectric Strength (V/Mil) Dielectric Constant ( 1 MC dry) Dissipation Factor ( 1 MC dry)... 

Changes in electrical properties (electrical conductivity, dielectric constant etc.). 

Materials are important to mankind because of the benefits that can be derived from the manipulation of their properties. Examples include electrical conductivity, dielectric constant, magnetization, optical transmittance, strength and toughness. All of these properties originate from the internal structures of the materials. Structural features of materials include their t3 es of atoms, the local configurations of the atoms,and the arrangements of these configurations into microstructures. 

Electrical conductivity, dielectric constant, dissipation factor, and triboelectric behavior are electrical properties of polymers subject to low electric field strength. Materials can be classified as a function of their conductivity (K) in (Q/cm) as follows ... 

In many applications, AFLAS outperforms other elastomers because of the following characteristics (1) High temperature resistance (400 F long term 550-h°F shorter term) (2) Resistance to a wide range of chemicals (including acids, bases, steam, sour (H2S) oil and gas with amine corrosion inhibitors, oils and lubricants, hydraulic fluids of all types, brake fluids, bleaches, oxidizing agents, alcohol, etc.) (3) Durable physical properties (4) Excellent electrical resistance-Dielectric constant at 60 Hz of 2.5. 

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