Thermal and mechanical properties of composites prepared by polyamide-6 reinforced with silanized and funtionalized carbon fiber

A composite material is made by combining two or more materials – often ones that have very different properties. The two materials work together to give the composite unique properties. In this thesis, investigation of thermal and mechanical properties of carbon fiber-reinforced polyamide 6 was aimed. With this purpose, the composites were by handling the materials with extrusion compounding and injection molding techniques. Impact test, hardness test, and tensile test were performed for the mechanical characterization of the prepared composite samples. Differential scanning calorimetery (DSC) was used to determine the thermal properties of the composite samples, and scanning electron microscopy (SEM) for surfaces characterization. Polymeric matrix was reinforced by handling with four by weight different percentages of carbon fiber. In addition, comparatively, polymeric matrix was also reinforced by handling with two by weight different percentages of fiberglass. It was observed that hardness, impact strength and tensile modulus values were increased simultaneously by increasing the amount of carbon fiber, unlike elongation which showed the opposite reaction. Increasing in weight of carbon fiber doesn't make a remarkable change on DSC's results. However, SEM showed that adhesion between the fibers and the matrix is not very good. Tensile tests' results have observed that tensile strength hasn't been effected as much as tensile modulus did and that because, tensile modulus is dependent on carbon fiber volume fraction, while tensile strength is dependent on mean fiber's length. Studies show that the mean length of fiber becomes shorter with fiber reinforcing, studies also observed that mean length of fibers is being shortened much more when we use carbon fiber in reinforcing than when we use fiberglass.