Transient current (I-t), current-voltage (I-V) characteristics, and dc conductivity ln(σ) for bisphenol A corn-cobs (BPACC) sample were investigated. At higher temperatures, I-V characteristics reveal that the dc cur...Transient current (I-t), current-voltage (I-V) characteristics, and dc conductivity ln(σ) for bisphenol A corn-cobs (BPACC) sample were investigated. At higher temperatures, I-V characteristics reveal that the dc cur-rent for the sample undergoes two regions one due to ohmic conduction and the other has been attributed to Space charge limited current (SCLC). The activation energy (Ea), the electron mobility μo), effective electron mobility ?μe), the concentration of the charge’s concentrations in conduction band, trapping factor (θ) and the trap concentration (Nt) were calculated. At lower temperatures, the dc current exhibits a peculiar behavior for I-t regime and I-V characteristics. Transient current of BPACC sample exhibits approximately constant value at constant electric field and it has saturation value for I-V characteristics. The attained results suggest strongly the applicability of this material in the electrical applications.展开更多
Dielectric constant, ε', dielectric loss factor, ε', electric modulus, M, and ac conductivity, σac, of pure CPVC and that stabilized with 10 wt% of phenyl maleimide, PM, have been carried out. The dielectri...Dielectric constant, ε', dielectric loss factor, ε', electric modulus, M, and ac conductivity, σac, of pure CPVC and that stabilized with 10 wt% of phenyl maleimide, PM, have been carried out. The dielectric properties have been studied in the temperature and frequency ranges;310 K - 450 K and 1 kHz- 4 MHz, respectively. The incorporation of 10 wt% of PM as stabilizer for CPVC leads to reduce its Tg from 405K to 378K at 10 kHz. PM molecules within CPVC structure reduce the double bond, stabilizer effect, and cause the widely spacing between CPVC main chains, plasticizer effect.? Three dielectric relaxation processes namely ρ, α', and α were observed for pure CPVC. The first process was explained based on space charge formation or Maxwell-Wagner-Sillers, MWS, polarization. The second one is due to the segmental motion of the branching of CPVC. The third process occurs around the glass-rubber temperature, Tg, and is related to the micro-Brownian motion of the main polymer chain. Electric modulus and ac conductivity reveal that the conduction mechanism of CPVC is follow the correlated barrier hopping, CBH, while stabilized sample exhibits a quantum mechanical tunneling, QMT, type conduction.展开更多
The miscibility of chlorinated poly vinyl chloride (CPVC) and poly ethylene glycol (PEG) or poly ethylene succinate (PES) had been investigated using dielectric relaxation spectroscopy (DRS) over frequency and tempera...The miscibility of chlorinated poly vinyl chloride (CPVC) and poly ethylene glycol (PEG) or poly ethylene succinate (PES) had been investigated using dielectric relaxation spectroscopy (DRS) over frequency and temperature ranges;10 kHz - 4 MHz and 300 - 450 K, respectively. Three relaxation processes namely ρ-, α’-, and α-relaxation processes were observed for tan(δ) and the electric modulus M' of pure components and blends. The first one was attributed to the space charge polarization or the Maxwell-Wagner polarization. The second one was related to the amorphous regions located between the lamellar crystal stacks. The third one was due to the micro-Brownian motion of CPVC main chains. This process was found to be dependent in respect of temperature and frequency. The molecular dynamics of α-relaxation process were influenced by blending, i.e., the dielectric strength (De), the peak broadness, and the peak maximum of tan(δ) were found to be compositional dependent. Electric modulus analysis reveals that there is a role of electrode polarization for the dielectric relaxation.展开更多
文摘Transient current (I-t), current-voltage (I-V) characteristics, and dc conductivity ln(σ) for bisphenol A corn-cobs (BPACC) sample were investigated. At higher temperatures, I-V characteristics reveal that the dc cur-rent for the sample undergoes two regions one due to ohmic conduction and the other has been attributed to Space charge limited current (SCLC). The activation energy (Ea), the electron mobility μo), effective electron mobility ?μe), the concentration of the charge’s concentrations in conduction band, trapping factor (θ) and the trap concentration (Nt) were calculated. At lower temperatures, the dc current exhibits a peculiar behavior for I-t regime and I-V characteristics. Transient current of BPACC sample exhibits approximately constant value at constant electric field and it has saturation value for I-V characteristics. The attained results suggest strongly the applicability of this material in the electrical applications.
文摘Dielectric constant, ε', dielectric loss factor, ε', electric modulus, M, and ac conductivity, σac, of pure CPVC and that stabilized with 10 wt% of phenyl maleimide, PM, have been carried out. The dielectric properties have been studied in the temperature and frequency ranges;310 K - 450 K and 1 kHz- 4 MHz, respectively. The incorporation of 10 wt% of PM as stabilizer for CPVC leads to reduce its Tg from 405K to 378K at 10 kHz. PM molecules within CPVC structure reduce the double bond, stabilizer effect, and cause the widely spacing between CPVC main chains, plasticizer effect.? Three dielectric relaxation processes namely ρ, α', and α were observed for pure CPVC. The first process was explained based on space charge formation or Maxwell-Wagner-Sillers, MWS, polarization. The second one is due to the segmental motion of the branching of CPVC. The third process occurs around the glass-rubber temperature, Tg, and is related to the micro-Brownian motion of the main polymer chain. Electric modulus and ac conductivity reveal that the conduction mechanism of CPVC is follow the correlated barrier hopping, CBH, while stabilized sample exhibits a quantum mechanical tunneling, QMT, type conduction.
文摘The miscibility of chlorinated poly vinyl chloride (CPVC) and poly ethylene glycol (PEG) or poly ethylene succinate (PES) had been investigated using dielectric relaxation spectroscopy (DRS) over frequency and temperature ranges;10 kHz - 4 MHz and 300 - 450 K, respectively. Three relaxation processes namely ρ-, α’-, and α-relaxation processes were observed for tan(δ) and the electric modulus M' of pure components and blends. The first one was attributed to the space charge polarization or the Maxwell-Wagner polarization. The second one was related to the amorphous regions located between the lamellar crystal stacks. The third one was due to the micro-Brownian motion of CPVC main chains. This process was found to be dependent in respect of temperature and frequency. The molecular dynamics of α-relaxation process were influenced by blending, i.e., the dielectric strength (De), the peak broadness, and the peak maximum of tan(δ) were found to be compositional dependent. Electric modulus analysis reveals that there is a role of electrode polarization for the dielectric relaxation.
