Polymers are among the most important technical materials of today. In many applications polymers not only replaced materials such as wood, glass, paper and metals but also enabled the development of some products and areas that marked modern civilization. The first part of the paper gives an overview of the historical development of polymers and is graphically depicted global plastic production since the beginning of use in the industry to date. The annual total production of polymers exceeded production of iron and steel by two decades ago. Further on, the structure of the polymer is described and a polymerization systematization was carried out, in which special polymers were treated with regard to behavior at elevated temperature. Then, more importantly, the polypropylene, and the extensional properties test according to ISO 527. In the experimental part, the impact of the load speed on the tensile strength of the sample made of polypropylene (PP BC 250 MO) was examined. Samples were prepared on a hydraulic press, and tests were demonstrated on a universal mechanical ladder where the load speed varied to three levels.