Study of some physical properties of pre-treated single walled carbon nanotubes (SWCNTs) loaded polymer nanocomposites / Nermeen Kamal Seadawy Ibrahim ; Supervised Mohamed Abu Abdeen , Aboud Ibrahim Aboud , Mohamed Hamdy Othman

Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Physics

Polymers form a very important class of materials without which our life seems very difficult. Since the last century, polymeric materials have been widely used in many areas, such as in civil life and military applications. Now polymers are the fastest growing materials in the world. Between 1980 and 1990, the production of plastics increased by 62% while that of steels decreased by 21%. The annual overall production of polymeric materials has exceeded that of metal materials if computed in volume. Fillers are added into polymer matrix for one or more reason such as, light weight, reduce cost, increase modulus (stiffness), reduce shrinkage, improve crack resistance, control viscosity, and increase DC and AC electrical conductivities. In this work , samples of Poly vinyl chloride (PVC) loaded with different concentrations of functionalized and non-functionalized single walled carbon nanotubes SWCNTs (0.0, 0.2, 0.5, 1.0, 1.5, 2.0) were prepared by solution casting technique. The first part of this work studied the influence of 3Hydroxy-2-Napthoic acid (Ý-HNA) concentrations on both the dc and ac electrical conductivities as well as the tensile stress-strain behavior and from the achieved results, the concentration 0.04 wt% of Ý-HNA was chosen to be used in the rest of this work. The second part studied the effect of un-functionalized and Ý-HNA functionalized SWCNTs concentrations on the electrical properties of PVC. The concentrations of both types of SWCNTs and the temperature dependences of the dc electrical conductivity were, also, investigated. The frequency and SWCNTs concentration dependences of the dielectric permittivity, dielectric loss and ac electrical conductivity at room temperature for all nano-composites were studied. In the third part, the mechanical properties of functionalized and un-functionalized SWCNTs were studied. In this respect, stress strain behavior of all samples and dependence of the calculated values of the elastic modulus, tensile strength and strain at break, on either type of SWCNTs were studied. On the other hand, the rheological properties, namely ; the complex viscosity and the storage modulus were, also, studied as a function of frequency, Ý-HNA and SWCNTs concentrations for all samples. The glass transition temperature for the studied samples was determined from the temperature dependence of the storage modulus and loss tangent (tane)

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