Electrical relaxation dynamics in TiO2 – polymer matrix composites

Abstract. The present work deals with the effect of conductive carbon black (Ensaco 350G) on the physico-mechanical and electrical properties of chlorosulfonated polyethylene (CSM) rubber vulcanizates. The physico-mechanical properties like tensile strength, tear strength, elongation at break, compression set, hardness and abrasion resistance have been studied before and after heat ageing. Up to 30 parts per hundred rubber (phr) filler loading both tensile and tear strength increases beyond which it shows a decreasing trend whereas modulus gradually increases with the filler loading. Incorporation of carbon black increases the hysteresis loss of filled vulcanizates compared to gum vulcanizates. Unlike gum vulcanizate, in filled vulcanizates the rate of relaxation shows increasing trend. The bound rubber content is found to increase with increase in filler loading. Dielectric relaxation spectra were used to study the relaxation behavior as a function of frequency (100 to 10 6 Hz) at room temperature. Variation in real and imaginary parts of electric modulus has been explained on the basis of interfacial polarization of fillers in the polymer medium. The percolation limit of the conductive black as studied by ac conductivity measurements has also been reported.

Section: Introductionmentioning

confidence: 97%

Physico-mechanical and electrical properties of conductive carbon black reinforced chlorosulfonated polyethylene vulcanizates

Nanda¹,

Tripathy²

2008

“…Integrated decoupling capacitors, acoustic emission sensors, electronic packaging, self-current regulators, self-heating systems, elements for circuit protection, electrostriction artificial muscles or skins and memory switches are some possible applications [1][2][3][4][5][6]. Moreover, electrical properties such as dielectric permittivity and conductivity can be suitably adjusted by simply controlling the type and the amount of ceramic inclusions.…”

Section: Introductionmentioning

confidence: 99%

“…Polymer matrix ceramic filler composites receive, recently, increased attention because of their interesting electrical, electronic and functional properties [1][2][3][4][5][6]. Integrated decoupling capacitors, acoustic emission sensors, electronic packaging, self-current regulators, self-heating systems, elements for circuit protection, electrostriction artificial muscles or skins and memory switches are some possible applications [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Electrical response and functionality of polymer matrix-titanium carbide composites

Raptis¹,

Patsidis²,

Psarras

2010

Self Cite

Abstract. The dielectric response and conductivity of polymer matrix-titanium carbide composites was examined by means of Broadband Dielectric Spectroscopy in the frequency range of 10 -1 -10 7 Hz and over the temperature range of 40-150°C, varying the filler content. Dielectric data were analyzed via the electric modulus formalism. Recorded relaxations were attributed to interfacial polarization, glass to rubber transition and local motions of polar side groups. Alternating current conductivity varies up to seven orders of magnitude with both frequency and temperature. Direct current conductivity increases with temperature, although the rate of its alteration does not remain constant in the examined temperature range. In the low temperature region (up to 60°C) increases at a higher rate, while right afterwards approaches rather constant values. Finally, in the high temperature range (above 90°C) conductivity raises again but at a lower rate. This behaviour adds functionality to the composites' performance and could be exploited in developing self-current regulators.

“…In these nanocomposites, the final properties depend essentially on parameters such as grain size of ceramic, method of preparation of composites and on the dispersion of the ceramic particles into the polymer matrix [2][3][4][5]. PVDF is semicrystalline polymer with pyro and piezoelectric properties.…”

Section: Introductionmentioning

confidence: 99%

Dielectric relaxations in PVDF/BaTiO3 nanocomposites

Chanmal¹,

Jog²

2008

291

164

Abstract. The present work aims at the study of molecular relaxations in PVDF/BaTiO3 nanocomposites using broadband dielectric spectroscopy. The nanocomposites of PVDF with BaTiO3 (10-30% by wt%) are prepared using simple melt mixing method. In dielectric permittivity study, two relaxation processes are identified corresponding to the crystalline, glass transition in the PVDF/BaTiO3 nanocomposites. The peaks shift to higher frequencies as the temperature is increased. Electric modulus formalism is used to analyze the dielectric relaxations to overcome the conductivity effects at low frequencies. In M″ spectra two peaks are observed only at high temperature and low frequency whereas a single relaxation peak appears at low temperatures. The single relaxation peak appearing at low temperatures is the αc relaxation attributed to crystalline chain relaxation in PVDF and the second relaxation peak which appears only at high temperatures and at a frequency lower than αc relaxation is identified as MWS relaxation. The temperature dependence of αc relaxation and MWS relaxation follows Arrhenius type behavior.