The aim of this thesis is to investigate the influence of polycaprolactone (PCL) on the properties of polyamide 12 (PA12) and polycaprolactone (PCL) blends, with special emphasis on their thermal, surface, and mechanical properties. Polymer blends are increasingly used in industry as they enable the combination of beneficial properties of different polymers, resulting in materials tailored to specific needs and applications. PA12 is a thermoplastic polymer known for its high strength, chemical resistance, and stability, while PCL, a biodegradable polymer, contributes to the flexibility and easier processing of the material. The use of these polymer blends opens up the possibility of creating new materials with improved properties suitable for various industrial applications, including medical devices, packaging, automotive, and aerospace industries. In order to thoroughly investigate the properties of the blends, tests were conducted using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), which provide insight into the thermal stability and transition temperatures of the materials. Additionally, surface properties were analyzed by measuring the contact angle to calculate the surface free energy, while mechanical properties were determined through tensile testing. This thesis contributes to a better understanding of the behavior of PA12/PCL polymer blends and provides a foundation for further research focused on the compatibility of components within the polymer blend, as well as its stability and industrial application.