Author name:
فاضل كريم فرحان
Supervisor name:
صلاح قدوري هزاع
Abstract:
In this thesis, thermal conductivity, bending strength, erosion rate, and Vickers hardness, for (epoxy - un saturated polyester) blend reinforced with multi - wall carbon nano tubes ,have been studied, in terms of thermal and mechanical properties, which are subject to change in different (MWCNTs) volume fraction which are (0.1,0.2,0.3, 0.4)%.The nano composites candidates for this work are multi - wall carbon nano tubes), and blend matrix (epoxy - un saturated polyester). Ultrasonic dispersion and magnetic stirring techniques are used to prepare the nano composites specimens follow with cold - casting technique using Teflon molds at standard conditions.Lee’s disk technique is used to measure thermal conductivity. Oxy - acetylene flame technique is used to determine erosion rate. Instron machine is used to measure bending strength. Micro hardness Vickers technique is used to determine the hardness. Simulation programs of heat transfer in three dimensions for erosion test for blend and blend - nano composites specimens are carried out using finite difference method.Thermal conductivity results show that , values increase progressively by succession of volume fraction of fillers, become where is 0.7W/m.K for matrix blend ,and 3.8W/m.K for volume fraction 0.4% . Erosion rate behaves inversely, where it drops at high volume fraction 0.4% of fillers it is 0.19mm/s . Bending strength results show, that increases progressively of volume fraction (0.1,0.2,0.3)% of MWCNTs , become where it is (93,109,118) MPa , by succession ,and it drops at high volume fraction 0.4% of fillers it is 98MPa, the Y - modulus results show that , values increase progressively by succession of volume fraction of fillers, 1.4GPa for matrix blend, and 3.0GPa for 0.4%vol . Hardness Vickers results show that values increase progressively by succession of volume fraction of fillers ,14MPa for matrix blend, and 21MPa for 0.4%vol . Simulation thermal conductivity results, which are calculated according to Nielsen model, are compared, with the experimental results. From the results it can be observed, that the experimental values, are nearly the same as simulation values in heat flow flux direction. Erosion simulation values 0.2mm/s come higher than experimental values 0.19mm/s, this could be explained, by the interface effect of nanocomposites, which have high strength, strong bond force, and density values are evidence to that.Atomic force microscopy, coupled with auxiliary microscopy, and nanoparticle size measurements for powder MWCNTs are employed to aid interpretation of results. The nanocomposites under the study can be used in applications, which need high thermal dispersion and high erosion resistance, as thermal insulators.
