Characterization of Addition Copper chloride on Polystyrene.
Ahmed Hashim(1), Bahaa Hussien(2), Mohammed Hadi (3) , (4)
(1,2)Babylon University, College of Education, Department of physics, Iraq. (3,4) Babylon University, College of Basic Education , Department of General Science, Iraq.
E-Mail: ahmed_taay@yahoo.com
Abstract
In this paper, the electrical properties of randomly mixed consisting of polystyrene and copper chloride has been investigated. The samples of composites has been prepared by adding copper chloride on the polystyrene with different weight percentages from copper chloride with polymer and by different thickness. Results showed that the conductivity is increased with increasing the copper chloride concentrations and temperature. Also the activation energy of D.C electrical conductivity changed with increasing of additional copper chloride.
Keywords: Polystyrene, copper chloride, activation energy, conductivity .
Introduction
Composites are made from two or more chemically distinct and insoluble phases materials that when combined are better (stronger, tougher, and/or more durable) than each would be separately. Polymeric composite materials are widely used in weight sensitive applications due to their high strength-to weight and stiffness-to-weight ratios compared with metallic materials. The weight and fuel savings offered by composite materials makes them attractive not only to the military, but also to the civilian aircraft, space, solar vehicles, and automobile industries[1]. Composite materials, which are usually fabricated with an emphasis on properties such mechanical strength, have also been used in electronic applications. Integrated decoupling capacitors, angular acceleration accelerometers, acoustic emission sensors and electronic packing are some potential applications[2]. This paper deals with study D.C electrical properties of (PS-CuCl2) composites.
Materials and Methods
The materials used in this paper are polystyrene and copper chloride. The weight percentages of copper chloride are (0,1,2, and 3)wt.%. The samples were prepared using casting technique thickness ranged between (215-535)?m. The resistivity was measured over range of temperature from (30 to 80)oC using Keithly electrometer .The electrical conductivity was calculate by :
Where :
A = guard electrode effective area.
R = volume resistance (Ohm) .
L = average thickness of sample (cm) .
The activation energy was calculated using equation :
? = ?o exp(-Ea/kBT)…………………..(2)
? = electrical conductivity at T temperature
?0 = electrical conductivity at absolute zero of temperature
KB = Boltzmann constant
Eact = Activation Energy
Results and Discussion:
The variation of electrical conductivity with weight percentages of copper chloride at room temperature is shown in figure(1). The figure shows that the increases of the electrical conductivity with weight percentages of copper chloride, this is relate to increase of ionic charge which can be increased due to increasing filler content[3]
Figure(2) shows the variation of the electrical conductivity for (PS-CuCl2) composite with temperature. The figure shows that the bulk electrical conductivity increases with the increase of the temperature of (PVA- CuCl2) composites. This means that these materials have resistance of negative thermal coefficient; that is, having the resistance decrease with the increase of temperature[4].
This is because polymer chains and copper chloride ions could act as traps for the moving charge carriers by hopping process, with the increase of temperature, the motion of polymer chains increase; as a result of the ions of copper chloride LiF move. Consequently, the trapped charge carriers are releasing and the conductivity for composite increase as a result for the increase of the charge carriers and mobility of these charges[4].
Figure (3) shows the relationship between the ln(conductivity) and inverted absolute temperature of the composites, using equation(2), was calculate activation energy, the high activation energy values for neat sample and low copper chloride concentration sample can be attributed to the thermal movement of the ions and molecules, whereas the low activation energy values for the samples of higher copper chloride content can be attributed to the electronic conduction mechanism which is related to the decreasing of the distance between the copper chloride particles . [5] as shown in figure(4).
Conclusions
1. The D.C electrical conductivity of the polystyrene increases by increasing copper chloride concentrations and temperature.
2. The activation energy of D.C electrical conductivity decreases by increasing copper chloride concentrations.
References
[1] Fahad A. Al-Zahrani, Ali A. Al-Masmoom, and U.A.Khashaba, 2009, " Impact of Polymers and Polymeric Composites on the Development of New Designs in Mechanical, Electrical, and Civil Engineering: A Review", MASAUM Journal Of Reviews and Surveys, Vol. 1, No.2.
[2] Vishal S., Kulkarni and Rama R, 2003,"Dielectric properties of Aluminum-Epoxy composites", J. of Appl. polymer Sci., Vol. 90, pp.(3602-3608).
[3] He X. JDu ., J. H. and Ying Z. , 2005, " positive temperature coefficient effect in multwalled carbon nanotube high – density polyethylene composite", J. Appl. Phys. Letters, Vol. 86, China.
[4] Sindhu S., Anantharaman R, Bindu P. and Kurian P., 2002,J. of Bull. Mater. Sci., Vol.25, No.7,P(599-607), Indian Academy of Scinences.
[5] Ahmed M. S. and Zihilif A. M. , 1992, " The electrical conductivity of polypropylene and Nickel- Coated carbon Fiber composite ",J. Mater. Sc. Vol. 25 , No. 706, Uni of Jordan , Amman , Jordan.