Investigation of mechanical and thermal properties of boron minerals doped plastic materials

In this study; mechanical and thermal properties of boron containing polyethylene and polyurethane was investigated. This thesis consists of two main parts that are polymer manufacturing and characterization. Polymer blends are manufactured by extrusion method within the limits of 15% boron mineral content followed by using the injection molding method to obtain tensile and impact tests samples. To understand the mechanical properties of the samples, tensile test, impact test and hardness test is utilized. Additionally, thermal characteristics and properties are investigated using Thermogravimetric analysis and Differential Scanning Calorimetry. Experimental data showed that there is no significant decrease in tensile strength of the materials and a notable increase in stiffness of materials. In addition, polyethylene based samples indicate a decline in elongation at break whereas there is a variety of results obtained from polyurethane samples. While there was a notable decrease in the impact resistance of polyethylene-based materials, contrary to expectation there has been an increase in some polyurethane based samples. Hardness values are found to be improved for both sample types. Similar results were obtained in the two methods used for analysis the thermal properties. Although it is not as much as expected, there is a noticeable improvement in the thermal properties of both materials. Additionally, while Scanning Electron Microcopy (SEM) was utilized to monitor the dispersion of mineral filler, Melt Flow Index (MFI) measurements were used to determine the flow dynamics that are important for production. SEM images reveal that mineral filler is not as well-dispersed as expected. When the flow properties were examined an increase in viscosity was observed as expected, except for some samples.