Free Essay

Conductive Carbon Black

In: Other Topics

Submitted By rajadhanapal76
Words 5103
Pages 21
J Polym Res (2012) 19:16 DOI 10.1007/s10965-012-0016-1


Influence of matrices chemical nature on the dynamic mechanical and dielectric properties of rubber composites comprising conductive carbon black
Omar A. Al-Hartomy & Ahmed A. Al-Ghamdi & Falleh Al-Solamy & Nikolay Dishovsky & Mihail Mihaylov & Milcho Ivanov & Farid El-Tantawy
Received: 14 February 2012 / Accepted: 22 October 2012 # Springer Science+Business Media Dordrecht 2012

Abstract The study presents the effect that elastomeric matrices different in their chemical nature (a non-polar and crystallizing natural rubber and a polar and non-crystallizing acrylonitrile-butadiene rubber) have upon the dynamic mechanical and dielectric properties of the composites comprising different amounts of conductive carbon black. Dynamic mechanical thermal analysis (DMTA) and Dielectric thermal analysis (DETA) are the techniques used for studying the structure-properties relationships of the composites. The experimental results show that the matrices studied and their specific properties have a great impact
O. A. Al-Hartomy : A. A. Al-Ghamdi Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia O. A. Al-Hartomy Department of Physics, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia F. Al-Solamy Department of Mathematics, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia F. Al-Solamy Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia N. Dishovsky (*) : M. Mihaylov : M. Ivanov Department of Polymer Engineering, University of Chemical Technology and Metallurgy, 8 Kl. Ohridski Blvd., 1756, Sofia, Bulgaria e-mail: F. El-Tantawy Department of Physics, Faculty of Science, Suez Canal University, Ismailia, Egypt

upon both the dynamic mechanical and dielectric parameters of the composites based on them. The chemical nature, structure and specific characteristics of the matrix affect the storage modulus, glass transition temperature, elasticity behavior, high-elasticity, energy dispersion, dielectric permittivity and DETA tan δ of the composites investigated. The matrix effect dominates at lower filler amounts and determines the properties of the composites. Keywords Rubber composites . Carbon black . DMTA . DETA . Viscoelastic Properties

Introduction Dynamic mechanical thermal analysis (DMTA) is a technique where a small deformation is applied to the sample investigated in a cyclic manner. The force applied to the sample oscillates allowing to obtain information about the changes in stiffness and damping, which are reported as modulus and tan δ. Because the applied force is sinusoidal one can express the modulus as an in-phase component (so called storage modulus) and an out of phase component (the loss modulus). The storage modulus (E’) is the measure of the sample elastic behavior, the loss modulus (E”) is the measure of the viscous response of materials. The ratio of the loss modulus to the storage modulus (E”/E’) is tan δ and it is a measure of the energy dissipation in the material. Tan δ is also an indicator of the viscoelasticity of the sample [1]. Viscoelasticity is the ability of a composite to exhibit both elastic and viscous behavior. Dielectric thermal analysis (DETA) is a technique for studying molecular dipolar relaxation as a function of temperature and frequency. By studying the relaxation spectra the intermolecular cooperative motion and hindered dipolar rotation can be deduced. Due to the presence of an electric

Page 2 of 8

J Polym Res (2012) 19:16

field, the composite undergo ionic, interfacial and dipole polarization and this polarization mechanism largely depends on time scales. As a result this technique reveals the dynamic of the macromolecular chains of the rubber matrix [2]. With the development of electronic industry, some special dielectric materials with high and/or low dielectric permittivity are attracting a remarkable attention in academic and industrial fields. The dielectric properties of the insulative materials could be adjusted by dispersing different kinds of fillers into polymer matrices to form the polymer/ filler composites. With changing the concentration of fillers, the dielectric permittivity could be changed. When filler with low dielectric permittivity is added into the polymers, the composites with low dielectric permittivity could be acquired. While the inorganic or organic fillers with high dielectric permittivity are added into the polymers, composites with high dielectric permittivity should be acquired [3]. The electroconductive rubber compounds find wide application in the production of versatile static electricity insulators. Usually the electrical conductivity (percolation threshold) of the vulcanizates comprising conventional (low structure) carbon black is achieved at a high filling degree (70–80 phr). However, the higher filling degree causes considerable changes in the elastic properties of the vulcanizates. In other cases, filling the rubber compounds with small quantities of high structure electrically conductive carbon black affords the percolation threshold at lower filler amounts with no significant changes upon the mechanical properties of the vulcanizates based on the said compounds. It is obvious that DMTA and DETA are important and powerful tools for studying the structure-properties relationships in polymer composites and nanocomposites [4]. They elucidate the mechanical behavior and the molecular structure of rubber based materials. The dynamics of polymer chain relaxation and molecular mobility of polymer main chains and side chains is one of the factors that determine the viscoelastic properties of the polymeric macromolecules [5, 6]. There is a number of papers reporting on DMTA and DETA studies presenting the effect that the filler’s structure
Table 1 Typical properties of the carbon black used Iodine adsorptiona mg/g 300 a b

and chemical nature have on the composites characteristics mentioned above (tan δ peak height, the shift in the peak position, the values of storage modulus, the value of loss modulus, polymer chain dynamics) [7–20], which describe the composites macroproperties (elastic behavior, viscous response, viscoelasticity, energy absorption). However, few are the articles reporting on DMTA and DETA investigations on the effect of the elastomeric matrix. [21–25]. The goal of this paper is to present how under the same conditions the dynamic, mechanical and dielectric properties of composites filled with conductive carbon black depend on the chemical nature and structural characteristics of two completely different elastomeric matrices (a polar noncrystallizing and a non-polar crystallizing one).

Experimental Materials Acrylonitrile-butadiene rubber (NBR) Acrylonitrile-butadiene rubber, containing 26 % ACN (Krynac 2645F, produced by Lanxess) was used in our investigations. Natural rubber (NR) Natural rubber—SVR 10 was purchased from North Special Rubber Corporation of Hengshui, Hebei Province, China. Characterization of the carbon black used Furnace carbon black Printex L6 (produced by Evonik) was chosen for the experiments. Some of the most often used carbon black characteristics are surface area, dibutylphtalate (DBP) adsorption, iodine adsorption number, etc. The main characteristics of the filler are summarized in Table 1 [26].

CTAB-surface areab m2/g 136

BET surface areac m2/g 150

DBP absorptiond ml/100 g 119

CDBP absorptione ml/100 g 103

Primary particle size, nm 10–80

The iodine number (iodine adsorption) reflects a “not true” surface area, because it is affected by porosity, surface impurities and surface oxidation

The cetyltrimethyl ammonium bromide (CTAB) surface area analyzes the so-called external surface area which corresponds to the accessible surface area for an elastomer c d e

BET (Brunauer, Emmett, Teller) nitrogen adsorption surface area provides the “total” surface area including porosity DBP absorption–dibutylphtalate absorption CDBP absorption–crushed DBP

J Polym Res (2012) 19:16

Page 3 of 8

Preparation and vulcanization of rubber compounds The rubber compounds were prepared on an open two-roll laboratory mill (L/D 320×360 and friction 1.27). The speed of the slow roll was 25 rpm. The formulations of the compounds prepared and studied are shown in Tables 2 and 3. The experiments were repeated for verifying the statistical significance. The ready compounds in the form of sheets stayed 24 h prior to their vulcanization. The optimal curing time was determined by the vulcanization isotherms taken on an oscillating disc vulcameter MDR 2000 (Alpha Technologies) at 150 °C for NR based composites and at 160 °C for NBR based composites, according to ISO 3417:2002.

the temperature range from −80 °C to 80 °C using a heating rate of 3 °C/min under single cantilever bending mode. The dimensions of the investigated samples were as follows: width 10 mm, length 25 mm and the thickness measured using a micrometer varied between 1 and 2 mm. Dielectric thermal analysis Dielectric properties (Permittivity (ε’) and dielectric loss angle tangent (DETA tan δ)) were investigated using a Dielectric Thermal Analyzer (Rheometric Scientific) at 4 different frequencies (1 kHz, 10 kHz, 100 kHz and 1 MHz) and temperature 30 °C and 100 °C on a sample having a diameter approximately 32 mm and 1 mm thickness.

Measurements Dynamic mechanical thermal analysis (DMTA) Dynamic properties (Storage modulus (E’) and mechanical loss angle tangent (tan δ)) of the studied vulcanizates were investigated using a Dynamic Mechanical Thermal Analyzer Mk III system (Rheometric Scientific). The data were obtained at 5 Hz frequency and strain amplitude 64 μm in Results and discussion In order to explain adequately the properties of elastomercarbon composites one should take into account the bellow specifics of their matrices. Natural rubber is a linear polymer of an unsaturated hydrocarbon called isoprene (2-methyl butadiene).








CH2 n

Isoprene [2-methyl butadiene]

Natural rubber [Polyisoprene]

Crude rubber is a tough and elastic solid. With rising temperature it becomes soft and sticky. The most important property of natural rubber is its elasticity. When stretched, it
Table 2 Composition of the NBR based rubber compounds NBR 0 Acrylonitrile-butadiene rubber (NBR-26 ACN) ZnO Stearic acid Carbon black-Printex L6 TBBSa Sulfur a expands and attains its original state, when released. That is due to the coil-like structure of its molecules which straighten out when stretched and when released, they coil up again.

NBR 10 100 4 2 10 0.8 2.25

NBR 20 100 4 2 20 0.8 2.25

NBR 30 100 4 2 30 0.8 2.25

NBR 40 100 4 2 40 0.8 2.25

NBR 50 100 4 2 50 0.8 2.25

100 4 2 – 0.8 2.25

TBBS N-tert-Butyl-2-benzothiazolesulfenamide

Page 4 of 8 Table 3 Composition of the NR based rubber compounds Natural Rubber SMR 10 ZnO Stearic Acid Carbon black Printex L6 TBBSa Sulfur

J Polym Res (2012) 19:16

NR 0 100 5 2 0 0.8 2.25

NR 10 100 5 2 10 0.8 2.25

NR 20 100 5 2 20 0.8 2.25

NR 30 100 5 2 30 0.8 2.25

NR 40 100 5 2 40 0.8 2.25

NR 50 100 5 2 50 0.8 2.25


TBBS N-tert-butyl-2benzothiazolesulfenamide

Therefore applied stress can easily deform rubber. Noteworthy is that when the stress is removed, the rubber retains its original shape. Raw natural rubber is elastic over a narrow temperature range from 10 to 60 °C. That is why articles made of raw natural rubber fail to perform in hot weather. Pure rubber is a transparent, amorphous solid which upon stretching or prolonged staying crystallizes. It is a non-polar elastomer and a dielectric possessing very high values of volume resistivity [27, 28]. Acrylonitrile-butadiene rubber (NBR) is a synthetic rubber produced by copolymerization of acrylonitrile (ACN) with butadiene, mainly in a trans-1.4 structure.

Dynamic mechanical thermal analysis of the composites Figure 1 presents the temperature dependences of the storage modulus (E’) for NBR (Fig. 1a) and NR (Fig. 1b) vulcanizates comprising various amounts of conductive carbon black. As seen from Fig. 1 NBR vulcanizates are in the glass state in the −60 °C÷−30 °C range and NR vulcanizates are in the glass state in the −80 °C÷−40 °C region. In the above temperature intervals the storage modulus (E’) values for NR based vulcanizates are slightly higher than those for NBR ones. That is due to differences in the chemical nature of the said elastomers. As already mentioned, storage modulus (E’) is a measure of the elastic behaviour of the material studied. Obviously, NR and its vulcanizates are more elastic than NBR and its vulcanizates. That difference in the properties of the two rubbers is well known [28–30]. During the transition from the glass into the high-elastic state occurring at about −30 °C for NBR composites and at about −40 °C for NR composites, storage modulus start to decrease with the increasing temperature. Тhis sharp decrease over 2–3 decades corresponds to the primary relaxation process associated with the glass-high elastic transition of the material [13]. As one can see later, this modulus drop corresponds also to an energy dissipation phenomenon observed during the concomitant relaxation process, where tan δ passes through a maximum. Then the storage modulus reaches a plateau around 1 MPa, corresponding to the rubber state. Generally the storage modulus values for NR in the said plateau are higher because its elasticity is better than the one of the NBR.




CH2 m



The acrylonitrile (ACN) content is one of the two primary criteria for defining every NBR. The ACN level, by reason of polarity, determines several basic properties, such as oil and solvent resistance, low temperature flexibility, glass transition temperature (Tg) and abrasion resistance. Generally acrylonitrile-butadiene rubber can be used down to about −30 °C but special grades of NBR can work at lower temperatures too. Acrylonitrile-butadiene rubber belongs to the class of unsaturated copolymers of acrylonitrile and butadiene. The rubber is generally resistant to fuel and oils. It has inferior strength and flexibility, compared to natural rubber. It is a strongly polar (due to the nitrile group presence in its structure), non-crystallizing elastomer and a semiconductor [27, 28].
Fig. 1 Storage modulus (E’) dependency on the temperature at various filler content for (a) NBR and (b) NR based composites

J Polym Res (2012) 19:16 Fig. 2 Dependency of mechanical loss angle tangent (tan δ) on the temperature at various filler content for (a) NBR and (b) NR based composites

Page 5 of 8

In the −20 °C ÷ −80 °C range wherein the samples studied are in the high-elastic state, storage modulus (E’) values for NR (Fig. 1b) vulcanizates increase with the increasing amount of conductive carbon black. That is on account of the restricted, decreased mobility of the macromolecules following their immobilization onto the fillers surface and first of all because of the immobilization onto carbon black particles. In correspondence with [31] the decrease in mobility leads to an increase in E’ which allows to use this effect as a measure for fillers reinforcing activity. In the the −20 °C÷ 80 °C range storage modulus (E’) values for NBR (Fig. 1a) composites are also higher at higher filler amounts but the tendency is not as that pronounced. As a whole storage modulus (E’) values for NBR, although remaining lower in most cases, are quite close to those of NR which is probably due to NR crystallizability. Hence, the effects of the filler and its reinforcement are lesser than those in the case of NBR composites. Consequently the storage modulus (E’) values for the two types of elastomer matrices are equalized in a way. Mechanical loss angle tangent (tan δ) being the ratio between the dynamic loss modulus (E”) and dynamic storage modulus (E’) (tan δ0E”/E’) illustrates the macromolecules mobility as well as the phase transition in the polymers [30]. Figure 2 presents the temperature dependence of mechanical loss angle tangent (tan δ) for NBR (Fig. 2a) and NR (Fig. 2b) vulcanizates comprising various amounts of conductive carbon black.
Fig. 3 Dielectric permittivity (ε′) dependence on the filler amount and frequency for the composites on the basis of (a) NBR and (b) NR at 30 °C

As seen from Fig. 2 there are not considerable differences in the values of mechanical loss angle tangent (tan δ) as a function of the filler amount in the 0 °C÷80 °C range. However, in the said temperature range the values of mechanical loss angle tangent (tan δ) for NBR (Fig. 1a) increase slightly at higher filler amounts. It is known that tan δ peak corresponds to the glass transition temperature (Tg) of the composites. The figure shows that NBR has a Tg at about −30 °C, while NR has a Tg at about −40 °C. In both cases the filler concentration has no impact on vulcanizates Tg and higher filler amounts reduce the peak’s intensity of mechanical loss angle tangent (tan δ). This reduced intensity results from: (1) the decrease of the number of mobile units participating the relaxation process and (2) the decrease of the magnitude of the modulus drop associated with Tg. As seen from the figure the peak’s intensity of mechanical loss angle tangent (tan δ) for NR (Fig. 2b) vulcanizates is higher than that of NBR (Fig. 2a) ones. The changes in the values for mechanical loss angle tangent (tan δ) for NR and NBR based composites filled with conductive carbon black are utterly due to the different chemical nature of the elastomers studied. In the case of crystallizing NR (Fig. 2b) where the filler has a lesser reinforcing effect the peak’s intensity of mechanical loss angle tangent (tan δ) is reduced less than in the case of no-crystallizing NBR (Fig. 2a) [32]. On the other hand, the higher polarity of NBR matrix predetermines stronger filler-matrix interactions. The lower mechanical loss angle tangent (tan δ) confirms the said interaction to be stronger in than in the case of non-polar NR. As said

Page 6 of 8 Fig. 4 Dielectric permittivity (ε′) dependence on the filler amount and frequency for the composites on the basis of (a) NBR and (b) NR at 100 °C

J Polym Res (2012) 19:16

previously, tan δ is a measure of the energy dissipation in the material and also is an indicator of the viscoelasticity of the sample [1]. The results have shown that in the case of NR and vulcanizates based on it the high elasticity and energy dissipation are greater than those in the case of NBR and its vulcanizates. Dielectric thermal analysis (DETA) of the composites Figure 3 presents the dependence of dielectric permittivity (ε′) on filler amount and frequency at 30 °C for NBR (Fig. 3a) and NR (Fig. 3b) composites studied. As Fig. 3a shows in the case of NBR the increase in the filler amount leads to an increase in the dielectric permittivity (ε′) values at all frequencies studied. The frequency alternations in the cases of the unfilled NBR (Fig. 3a) based vulcanizates and of vulcanizates filled at low amounts of Printex L6 carbon black (up to 20 phr) have no considerable effect upon the dielectric permittivity (ε′) values which are determined by the elastomer matrix. At filler concentration over 20 phr dielectric permittivity (ε′) values decrease with the increasing frequency which is most pronounced at the highest filler concentrations. Regardless of the fact that there is not any drastic change in the dielectric properties that reveals reaching and passing the percolation threshold, the frequency dependence of ε′ in the case of vulcanizates filled at 30 phr (Fig. 3a) evidences that concentration to be the critical one for the occurrence of
Fig. 5 Dielectric loss angle tangent (DETA tan δ) dependence on the filler amount and frequency for the composites on the basis of (a) NBR and (b) NR at 30 °C

electrically conductive pathways enabling the polarization of the system. No difference in dielectric permittivity (ε′) values as a function of frequency studied is observed only for NR (Fig. 3b) composites (unfilled and filled at 10 phr). At higher filler concentrations, as it is in the case of NBR composites, the increasing frequency leads to a decrease of dielectric permittivity (ε′) values for NR composites, too. However, in the latter case the drastic change in the dielectric properties of the composites is at a lower filler concentration – at about 20 phr. That means the percolation threshold for NR composites is reached at filler concentrations lower than those for NBR ones, i.e. the effect of the introduced conductive carbon black is more pronounced. That might be explained by the NR crystallizability and higher specific volume resistivity. The latter parameter is more affected by the introduction of conductive filler. That effect is not that marked in the case of NBR which principally has a significantly lower specific volume resistivity. Probably the more ordered NR structure allows the occurrence of electrically conductive pathways at lower filler concentrations. As Fig. 3b shows, the increase in filler amount in NR composites does not cause significant changes in their dielectric properties when the percolation threshold is passed. Moreover, at high frequencies (100 kHz and 1 MHz) no changes are observed in the dielectric permittivity (ε′) values for filler concentrations higher than 30 phr.

J Polym Res (2012) 19:16 Fig. 6 Dielectric loss angle tangent (DETA tan δ) dependence on the filler amount and frequency for the composites on the basis of (a) NBR and (b) NR at 100 °C

Page 7 of 8

The dependences of dielectric permittivity (ε′) on filler amount and frequency at 100 °C for NBR and NR composites studied are presented in Fig. 4. The figure shows that at 100 °C the tendency of the changes in dielectric permittivity (ε′) observed at 30 °C to be the same. However, in the case of both elastomers dielectric permittivity (ε′) increases significantly with the raising temperature. At low frequencies (1 kHz) there are differences in the dielectric permittivity (ε′) values for NBR (Fig. 4a) composites at 100 °C. Those differences exist at low filler concentrations as well as for unfilled vulcanizates and for the ones filled with low amounts of Printex L6 carbon black. Such a change in the dielectric properties of the studied NBR vulcanizates is not observed at 30 °C and is likely due to the availability of a nitrile group in that elastomer. Possibly at low frequencies and higher temperatures the nitrile group causes a partial polarization of the rubber matrix. One should also take into account the fact that at 100 °C NR (Fig. 4b) is completely decrystallized what also affects the formation of electrically conductive pathways and its dielectric properties. The dependences of dielectric loss tangent angle (DETA tan δ) on filler amount and frequency at 30 °C for NBR and NR composites studied are presented in Fig. 5. As mentioned above, no significant changes are observed in dielectric permittivity (ε′) values. However, DETA tan δ values for both elastomers are dependent on the frequency at which the experiments were run, regardless of the filler amount. The dependence is more pronounced for the NR vulcanizates.
Table 4 Specific characteristics of raw non-vulcanized NR and NBR [28] Property Density, g/cm3 Dielectric permittivity at frequency of 1000 Hz 3) Dielectric loss tangent 4) Volume resistivity, Ω.m 5) Glass transition temperature, °C NBR 0.962 10.20 0.3100 3.107 −30 NR 0.915 2.55 0.0016 5.1012 −70

The filler amount affects the said parameter in the case of both elastomers. At low frequencies (1 kHz) the vulcanizates comprising Printex L6 carbon black at 50 phr have the highest DETA tan δ values which decrease with the increasing frequency. Figure 6 plotting the dependencies at 100 °C show higher DETA tan δ values. Nevertheless, the increasing frequency causes a decrease of DETA tan δ values for NBR vulcanizates regardless of the filler amount. The same results were obtained for NR vulcanizates. The only dissimilarity is that there is no visible difference in DETA tan δ values as a function of frequency for the unfilled composites and for those filled at 10 phr. Probably the different polarity and proneness to crystallization of the two matrices, as well as to the molecules mobility and to intermolecular interaction forces in each matrix determine the changes in DETA tan δ values for NR and NBR composites studied comprising different amounts of conductive carbon black. The two matrices used may be characterized as follows: A comparison of some of NR and NBR specific characteristics presented in Table 4 reveal the nature of the effects those matrixes have on the properties of the composites studied: As Table 4 shows the two elastomer matrices have very different properties and parameters which under the same all other conditions are the main reason for the different dielectric mechanical and dielectric behaviour of the composites based on them. Hence, the choice of matrix depends on the targeted properties of the composites and their particular applications.

Conclusions The study presents the effect that two elastomeric matrices different in their chemical nature (a non-polar and crystallizing natural rubber and a polar and non-crystallizing acrylonitrile-butadiene rubber) have upon the dynamic mechanical and dielectric properties of the composites comprising different amounts of conductive carbon black. Moreover,

Page 8 of 8

J Polym Res (2012) 19:16 11. Heinrich G, Klüppel M (2002) Recent advances in the theory of filler networking in elastomers. Adv Polym Sci 160:1–44 12. Thomas S, Stephen R (eds) (2010) Rubber nanocomposites. Wiley, Singapore 13. Angellier H, Molina-Boisseau S, Dufresne A (2005) Mechanical properties of waxy maize starch nanocrystal reinforced natural rubber. Macromolecules 38:9161–9170 14. Gatos KG, Sawanis NS, Apostolov AA, Thomann R, KargerKocsis J (2004) Nanocomposite formation in Hydrogenated Nitrile Rubber (HNBR)/Organo-Montmorillonite as a function of the intercalant type. Macromol Mater Eng 289:1079–1086 15. Wang Y, Zhang H, Wu Y, Yang J, Zhang L (2005) Preparation and properties of natural rubber/rectorite nanocomposites. Eur Polym J 41:2776–2783 16. Kalgaonkar RA, Jog JP (2008) Molecular dynamics of copolyester/clay nanocomposites as investigated by viscoelastic and dielectric analysis. J Polym Sci Part B Polym Phys 46:2539–2555 17. Rao YQ, Pochan JM (2007) Mechanics of polymer-clay nanocomposites. Macromolecules 40:290–299 18. Hernandez MC, Suarez N, Martinez LA, Fejoo JL, Monaco SL, Salazar N (2008) Effects of nanoscale dispersion in the dielectric properties of poly(vinyl alcohol)-bentonite nanocomposites. Phys Rev E77:051801 19. Page KA, Adachi K (2006) Dielectric relaxation in montmorillonite/polymer nanocomposites. Polymer 47:6406–6410 20. Psarras GC, Gatos KG, Karger-Kocsis J (2007) Dielectric properties of layered silicate-reinforced natural and polyurethane rubber nanocomposites. J Appl Polym Sci 106:1405–1411 21. Wan NY, Chin KP, Saad CS (2010) Comparison of epoxidised natural rubber (enr) 37.5 and enr 25/enr 50 physical blend: specialty polymer for “green tyre” application. IOP Conf Ser: Mater Sci Eng 11:012004 22. Small W, Wilson TS (2010) Crystallization behavior of virgin TR55 silicone rubber measured using dynamic mechanical thermal analysis with liquid nitrogen cooling, Lawrence Livermore National Laboratory, LLNL-TR-426277 23. Ghadir M, Zimonyi E, Nagy J (1994) Thermal investigation of silicone rubber containing imide-siloxane copolymers. Thermal Anal Calorimetry 41:1019–1029 24. Pandey AK, Setua DK (2006) Raw material and applications– study of damping behavior of rubber- plastic blend. Kautsch Gummi Kunstst 59:45–4 25. Boye WM, Terrill E (2011) Structure–property analysis of unfilled polyisoprene (IR) vulcanizates characterized by mechanical and rheological measurements, Rubber World, Aug. 22–27 26. Niedermeier CW Carbon blacks for electrically conductive rubber products, Evonik (Degussa), Technical report TR 812 27. Gozdiff M (2001) Acrylonitrile-butadiene rubber. In: Dick JS (ed) Rubber technology: compounding and testing for performance, 1st edn. Hanser Publishers, Munich, pp 193–201 28. Kornev A (2005) Technology of elastomeric materials, Istek, Moscow, (in Russian) 29. Dick JS (ed) (2001) Rubber technology, Hamser, Munich 30. Varghese S, Karger-Kocsis J, Gatos KG (2003) Melt compounded epoxidized natural rubber/layered silicate nanocomposites: structure-properties relationships. Polymer 44:3977–3983 31. Ramier J, Gauthier C, Chazeau L, Stelandre L, Guy L (2007) Payne effect in silica-filled styrene–butadiene rubber: influence of surface treatment. J Polym Sci Part B: Polym Phys 45:286–298 32. Wolf S, Wang M (1993) Carbon black reinforcements of the elastomers, In Carbon black, 2nd Edition, Marcel Dekker, New York

the matrices differ in some of their chief characteristics (dielectric permittivity, DETA tan δ, specific volume resistivity, Tg). The experimental results show that the matrices studied and their specific properties have a great impact upon both the dynamic mechanical and dielectric parameters of the composites based on them. The chemical nature, structure and specific characteristics of the matrix affect the storage modulus, glass transition temperature, elasticity behavior, highelasticity, energy dispersion, dielectric permittivity and DETA tan δ of the composites investigated. The matrix effect dominates at lower filler amounts and determines the properties of the composites. The introduction of a filler and its increasing amount choke that effect, so the composites characteristics become less dependent on the specifics of the matrix. However, some of the composite properties (elasticity behavior, high-elasticity, energy dispersion, dielectric permittivity) are predetermined by the elastomer even at a considerable filler amount. Hence, the choice of an elastomer matrix is of crucial importance for tailoring the properties of the composites.
Acknowledgments The present research is a result of an international collaboration program between University of Tabuk, Tabuk, Kingdom of Saudi Arabia and the University of Chemical Technology and Metallurgy, Sofia, Bulgaria. The authors gratefully acknowledge the financial support from the University of Tabuk.

1. Shaw M, MacKnight W (2005) Introduction to polymer viscoelasticity. Wiley, New York 2. Lobo H, Bonilla H (eds.) (2003) Handbook of polymer analyses, Dekker 3. Dang Z-M, Song H-T, Lin Y-Q, Ma L-J (2009) High and low dielectric permittivity polymer-based nanobybrid dielectric films. J Phys Conf Ser 152:012047 4. Gabbott P (ed) (2008) Principles and application of thermal analyses. Blackwell Publishing, Oxford 5. Ferry JD (1980) Viscoelastic properties of polymers. Wiley, New York 6. Heinrich G (2011) advanced rubber composites (Advances in Polymer Science, 239). Springer, Heidelberg 7. Fritzsche J, Das A, Jurk R, Stöckelhuber KW, Heinrich G, Klüppel M (2008) Relaxation dynamics of carboxylated nitrile rubber filled with organomodified nanoclay. Express Polym Lett 2:373–377 8. Das A, Costa FR, Wagenknecht U, Heinrich G (2008) Nanocomposites based on chloroprene rubber: Effect of chemical nature and organic modification of nanoclay on the vulcavizate properties. Eur Polym J 44:3456–3465 9. Das A, Jurk R, Stöckelhuber KW, Engelhardt T, Fritzsche J, Klüppel M, Heinrich G (2008) Nanoalloy based on clays: intercalated-exfoliated layered silicate in high performance elastomer. J Macromol Sci Chem 45:144–150 10. Eisenberg A, Hird B, Moore RB (1990) A new multiplet-cluster model for the morphology of random ionomers. Macromolecules 23:4098–4107

Similar Documents

Free Essay


...between a thousand and a million monomers. The polymers were commonly found in the nature (e.g. animals, plants). Meanwhile, the polymers were produced synthetical a lot to create different kinds of plastics. Vinyl, neoprene, polystyrene, nylon are very common synthetic polymers and Polyaniline (PANI) is also a conducting polymer. Polyaniline is among a family of conductive polymers, and has properties similar to some metals. It was discovered as “aniline black” in an organic form as part of melanin, a type of organic polymer in 1934. Melanin does many things in nature, including protecting the skin by regulating UV exposure through a polyaniline interaction. In a natural form, polyaniline is usually found folded with other polymers. In the late 1990s it became evident that polyaniline was a flexible and highly useful polymer, and could be used in applications ranging from intelligent windows to computer chips. Polyaniline is a unique type of polymer because it is a type of semiconductor. Polyaniline can be configured to conduct across a wide range, from being utterly non-conductive for insulation use to highly conductive for other electrical purposes. Polyaniline, like other polymers, is highly flexible, which makes it appealing for manufacturing use. Polyaniline comes in a granular form which can be mixed with an organic chemical and painted or sprayed onto a substance to form a smooth layer of polyaniline. It can also be molded into various shapes, as it was done in 2000......

Words: 657 - Pages: 3

Free Essay

Review of Battery

...Department of Mechanical and Manufacturing Engineering Faculty of Engineering EMM 5977 Independent Study Lecturer: Assoc. Prof. Ir. Dr. Nor Mariah Adam Name Lai Jee Inn Matrik No. GS 42146 INDIVIDUAL ASSIGNMENT Review on How to Improve the Efficiency of the Rechargeable Batteries-Lithium Batteries Lai Jee Inn GS42146 ABSTRACT Batteries are playing important role in our life especially in this high technology era. Laptop, mobile phone, camera and otherwise are using battery to make it to function. In order to improve the efficiency the batteries, several methods are discussed in this paper. INTRODUCTION In this advanced technology era, batteries have been commonly used by the consumers. We use them in different fields like cars, mobile phone, laptop and other else. (Hiroki Kitamura, 2012).Batteries is divided into two main groups which are primary and secondary batteries. (Clean Up Australia, 2009) Primary batteries are the batteries that normally use in dairy life such as remote control, clock but for this kind of batteries is a non rechargeable battery which means that we only can use it for one time and will be throw away after used. This kind of batteries is actually converting the chemical energy to electrical energy and they are normally known as the alkaline batteries. Secondary batteries are batteries that can be rechargeable and recycle after it cannot be recharge. This batteries mostly use for our mobile phone, laptop and other.......

Words: 5125 - Pages: 21

Premium Essay

A Case Study of Solar Cells- Unit 3- Edexcel

...Case Study of Solar Cells Solar cells or photovoltaic cells are a renewable source of electricity, harnessed from sunlight and thermal energy derived from the sun. It doesn’t emit any greenhouse gases (sulphur dioxide and carbon monoxide) when producing electricity. During a sunny and clear day, sun rays can provide over a 1000 watts of energy per square meter of the planet’s surface. Photovoltaic cells are made of semi conductive material such as silicon. As the light ray hits the solar cell, a fraction of the light is absorbed within the semi conductive material. The energy from the light knocks electrons loose causing them to collide, becoming delocalised. Solar cells can be used as a partial or entire source for energy, it allows the consumer to reduce energy costs and save money, the only issue being that due to installation costs, the payback time for solar power could be several years. Photovoltaic cells use a single junction to create an electric field within the semi conductive silicone. Within a single junction Photovoltaic cell, only the photons which an equal amount of energy or greater than the band gap (energy range in solid material where no exist) of the material can delocalise an electron to for an electric circuit. To convert more energy from the photons, more solar cells are used to create plural band gaps and junctions. Devices with multiple junctions (tandem cells) have a higher conversion efficiency, wasting less energy in the process, due to a......

Words: 996 - Pages: 4

Free Essay

Writing Mechanisms

...Preparation Questions: Item to Be Described (product and use) The OLED, Organic Light Emitting Diode, is the newest addition to the LED line of equipment. This new piece of equipment is the first ever design that allows the capability for High Definition TVs to be 80 inches wide, less than a quarter inch, and be rolled up when you’re not using it. This possibility and many more are capable through the solid-state devices of OLED. Composed of thin films of organic modules, OLEDs create light with the application of electrify. With this process, LEDs are taken to the next level when it comes to clarity and power efficiency. Audience (retail consumer, industrial expert, or other) The intended audience will be a retail consumer who is an expert technician or an experienced user with similar equipment. The audience will have some background knowledge but they are uniformed of the actual makeup of the OLEDs. These individuals want to know the technology behind the OLEDs and if it is worth their while to purchase the equipment. Purpose (Why is the document being produced?) This document is being produced to better inform the above audience. The overall purpose is to fully outline the OLED Mechanism and to allow the above audience to understand the advantages of the equipment compared to others that are out in the market. At the end, by informing the audience of the complete layout of the OLED, their interest will have improved and their chances of purchasing the......

Words: 3087 - Pages: 13

Free Essay

Fire Prevention

... atmospheric pollution and hazard to human and animal life. PHASES OF A FIRE First Phase – Incipient Oxygen content 20% - 21% with ceiling temperatures of approximately 37˚ C°. At this stage the produces of combustion are water vapour, carbon dioxide and sulphur dioxiode, and hot gases rising. Smoldering fires my last for a few seconds to several hours before breaking into flames. A large volume of smoke will be present until flaming starts and then progress is rapid. Second Phase – free burning, flame producing or steady state At this stage the oxygen content is 15% - 19% and the ceiling temperatures are above 537°C and the products of combustion are water vapour, carbon dixiode, carbon monoxide and sulphur dioxide. There large quantities of dark grey smoke and rapid destruction of combustible materials. It is at this point that flash over occurs. Flash over is when room and all its contents reach their ignition temperature and the area becomes fully involved in fire. Flame is now rapid. Third Phase – smoldering Oxygen content is less than 15% - 16% and ceiling temperature is above 815° C and soot is now added to the produce of combustion. Dense, dark flammable smoke and toxic flammable gases are being emoted and a black draft or smoke...

Words: 3488 - Pages: 14

Premium Essay


...CHAPTER 1 Introduction Chapter One is divided into eight parts: (1) Background of the Study, (2) Statement of the Problem, (3) Objectives, (4) Hypotheses, (5) Significance of the Study, (6) Research Framework, (7) Scope and Limitation of the Study, and (8) Definition of terms. Part One, Background of the Study, presents the introduction about the study and discusses the rationale for choosing the study. Part Two, Statement of the Problem, evaluates the purpose in conducting the study. Part Three, Objectives, enumerates the aim of the study. Part Four, Hypotheses, cites the assumptions on the result of the study. Part Five, Significance of the Study, describes the benefits that can be derived from the results of the study. Part Six, Research Framework, shows the theoretical framework of the study. Part Seven, Scope and Limitation of the Study, determines the extent of the study and identifies what are to be included in the study. Part Eight, Definition of terms, lists the important terms defined in conceptual and operational manner for the purpose of clarity. Background of the Study The aftermath of typhoon Yolanda or internationally known as typhoon Haiyan, is one of the worst typhoons Philippines have experienced. This calamity resulted to destruction of properties and this calamity has also caused blackouts all over the place. Electricity--- is badly needed......

Words: 3409 - Pages: 14

Free Essay


...rating for class B extinguishers indicates the approximate number of square feet of fire it can extinguish. Geometric symbol (red square) * Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive. Geometric symbol (blue circle) * Class D fire extinguishers are commonly found in a chemical laboratory. They are for fires that involve combustible metals, such as magnesium, titanium, potassium and sodium. These types of extinguishers also have no numerical rating, nor are they given a multi-purpose rating - they are designed for class D fires only. Geometric symbol (Yellow Decagon) * Class K fire extinguishers are for fires that involve cooking oils, trans-fats, or fats in cooking appliances and are typically found in restaurant and cafeteria kitchens. Geometric symbol (black hexagon) | Some fires may involve a combination of these...

Words: 1699 - Pages: 7

Free Essay

Alderly Problems

...Problems Nursing Intervention Confusion/Dementia Dementia is not a specific disease. It is a descriptive term for a collection of symptoms that can be caused by a number of disorders that affect the brain. People with dementia have significantly impaired intellectual functioning that interferes with normal activities and relationships. They also lose their ability to solve problems and maintain emotional control, and they may experience personality changes and behavioral problems such as agitation, delusions, and hallucinations. 1. Spend time with the Patient 2. Use touch to convey concern 3. Provide frequent reiteration of orienting data (e.g. time, place) 4. Have clocks or calendars in the environment 5. Explain all actions, procedures and routines to the patient 6. Address the patient by his/her name 7. Keep a routine activities Constipation refers to bowel movements that are infrequent and/or hard to pass. 1. Increase Fluid Intake 2. Daily Exercise 3. Increase fiber intake (e.g. fruits and vegetables) Complications associated with constipation include hemorrhoids from straining, anal fissures, rectal prolapse, and fecal impaction. Untreated constipation in institutionalized patients can lead to cemented lesions in the colon, megacolon, bowel blockage and perforation, peritonitis, and sepsis. Osteoporosis is a disease of bones that leads to an increased risk of fracture.[1] In osteoporosis the bone mineral density (BMD) is reduced, bone......

Words: 1638 - Pages: 7

Free Essay

Uses of Bamboo

...discovery and it has become a popular and eco-friendly choice for linens and towels. Bamboo charcoal is made by heating bamboo fibers at high temperatures of 800-1000 degrees Celsius. Once the bamboo has been turned into charcoal it is processed into nanoparticles. Using nanotechnologies these bamboo charcoal nanoparticles are then blended together with organic bamboo fibers and woven into yarn. Bamboo charcoal yarn is used to make the new line of towels, clothing and other garments. The many positive qualities of bamboo charcoal fabric include: Easier on sensitive skin – The fabric inhibits bacterial metabolism causing fewer allergic skin reactions than other fibers sterilized with antimicrobial agents. Reduces Static buildup – This is a conductive material so it keeps a balanced charge in fabric to help reduce static buildup. Superior Absorption & Deodorizing Ability – This trait is due to the highly porous structure of the bamboo fabric.  According to some research, bamboo charcoal can absorb formaldehyde at a rate of 16% ~ 19.39%; as for benzene, the rate is 8.69% ~ 10.08%; as for toluene, the rate is 5.65% ~ 8.42%; ammonia with the rate of 22.73% ~ 30.65%; chloroform with the high rate of 40.68%, and the lasting time can be up to 24d. And in the...

Words: 1550 - Pages: 7

Free Essay

Carbon Nanotube

...TERM PAPER OF CHEMISTRY TOPIC: CARBON NANOTUBE Submitted to Submit by: Mr. Balwant Singh Bhist Mr.Shailja Kant yadav Deptt. Of CHEMISTRY Roll. No. : - A02 Sec: - RC5911 REG NO.:-10905256 ACKNOWLEDGEMENT I take this opportunity to present my vote of thanks to all those guidepost who really acted as lightening pillars to enlighten our way throughout this project that has led to successful and satisfactory completion of this study. I would express my sincere gratitude to my parents for trusting and investing in me and my future and providing for all my needs and requirements. I also express my deep sense of gratitude to my teacher, Mr. Balwant Singh Bhist – Department of Chemistry, Lovely Professional University for her constant guidance and kind support throughout this project. I am heartily thankful to my friends Anil Choudhary, Pratik Anand, Suresh Hembrom for helping me with their thoughtful......

Words: 3070 - Pages: 13

Free Essay

Project on Pcb(Printed Circuit Board)

... Submitted By:- Harneek sani Group members Suraj kumar sahni (A 36) Sumeet jha (B 21) Aaditya baidwan (A 11) Section – JE101 Introduction A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board(PWB) or etched wiring board. Printed circuit boards are used in virtually all but the simplest commercially produced electronic devices. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB Assembly (PCBA). In informal use the term "PCB" is used both for bare and assembled boards, the context clarifying the meaning. Alternatives to PCBs include wire wrap and point-to-point construction. PCBs must initially be designed and laid out, but become cheaper, faster to make, and potentially more...

Words: 4957 - Pages: 20

Free Essay

Liquid Battery

...Homemade Batteries Homemade batteries are a popular subject with my readers. Making electricity from things you find around the house is a fun project. There are lots of easy ways to make homemade batteries. Basically, any two different kinds of metal can be placed in a conducting solution and you get a battery. Familiar homemade batteries include sticking copper and zinc strips into a lemon or a potato to make a battery. One quick battery is made from a soda can, the soda from the can, and some copper. Click on image for a larger picture The photo above shows a battery made by placing a strip of copper and a strip of aluminum into a glass of Coca-Cola (I used the sugar-free cherry flavored variety because that's what I found in the refrigerator). You can make the aluminum strip by cutting open the can. You will need some sandpaper to sand off the paint and plastic coating from the aluminum before using it. Or you can get strips of aluminum already free of coatings from a hardware store, or from our catalog. You can get copper flashing from a hardware store and cut out a strip of it, or you can use a bunch of copper wire (the more surface area exposed to the liquid, the more electrical current is produced). Or, as before, you can get pre-cut strips from our catalog. The aluminum-copper-coke battery will produce about three quarters of a volt. Click on image for a larger picture Using a zinc strip instead of the aluminum produces a little over a volt in the......

Words: 2668 - Pages: 11

Premium Essay

Essay On Corrosion

...Based on OMICS publishing group statement overall 2,28,000 No’s Research Articles has published related to corrosion. Polyaniline is the most attractive conductive polymer because of having reactive –NH– groups in polymer chain. The unique property of polyaniline, unlike all other electroconducting polymers, is existence in different forms depending on degree of oxidation, known as: leuoemeraldine, emeraldine and perningraniline. Leucoemeraldine, e.g. leucoemeraldine base, refers to fully reduced form; emeraldine, eg. Emeralddine base, is half-oxidized, while perningraniline, eg. perningraniline base, is completely oxidized form of polyaniline. The most conducting form of polyaniline is emeraldin salt, obtained by doping or protonation of emeraldine...

Words: 1713 - Pages: 7

Premium Essay

Ford Motor Company and the Safety Case

...David T. Narens Ford Motor Company and the Safety Case Harding University Abstract Ford Motor Company is a leader in influencing America and the world in automobiles. They are still true to the founding principles the company was founded on by Henry Ford by making affordable vehicles for the common man. They strive for innovation and creativity through their products. They have had safety issues in the past but it seems Ford finds a way to overcome challenges and put what matters most on top, the customer. Privacy Ford Motor Company has been around for most of the 20th century. Its great success is a result of many factors. Besides the ingenious creations and remarkable talent working for Ford, there is another reason that this company has had such longevity. The way that Ford Motor Company treats their employees is a major reason that Ford is such a dominant company in automobile industry. Ford treats their employees with the utmost respect and generosity. The employees can feel safe in their work environment without having to worry about their personal information being compromised my management. Ford trusts their employees and encourages them to bring any problem or concern to management so that it can be addressed and fixed. Ford does not have to invade their employee’s privacy to find out details about that employee. They create an environment of trust and loyalty. They create a morale that the employees feel comfortable in talking to others about......

Words: 2284 - Pages: 10

Premium Essay


...LESSON 1: History of Electronics The introduction of vacuum tubes at the beginning of the 20th century was the starting point of the rapid growth of modern electronics. With the vacuum tubes the manipulation signals became possible, which could not be done with the early telegraph and telephone circuit or with the early transmitters using high voltage sparks to create radio waves. Example: weak radio and audio signals can be amplified, audio signals such as music or voice can be superimposed radio waves. The development of a large variety of tubes designed for specialized functions made possible the swift progress of radio communication technology before World War II and the development of early computers during and shortly after the war. The transistor invented in 1948, has now completely replaced the vacuum tubes in most of its application. Incorporating an arrangement of semiconductor materials and electrical contacts, the transistor provides the same functions at reduced cost, weight and power consumption and with higher reliability. Subsequent advances in semiconductor technology, in part attributable to the intensity of research associated with the space exploration effort led to the development of the integrated circuit. Integrated circuits may contain hundreds of thousands of transistors on small piece of material and allow the construction of complex electronic circuits, such as those in microcomputers, audio, and video equipment and communication satellites. ...

Words: 2069 - Pages: 9