Using high doses of beta radiation for high-density polyethylene (HDPE) and its influence on the changes in the micromechanical properties of the surface layer has not been studied in detail so far. Specimens of HDPE were made with the injectionmoulding technology and irradiated with high doses of beta radiation (0, 132, 165 and 198) kGy. The changes in the micromechanical properties of the surface layer were evaluated using an ultra nano-hardness test. The results of the measurements showed a considerable increase in the micromechanical properties (indentation hardness, indentation elastic modulus) when high doses of beta radiation are used. The aim of this paper is to study the effect of ionizing radiation at different doses on the ultra nano-hardness of the surface layer of HDPE and compare these results with those for non-irradiated samples. The study was carried out due to the ever-growing use of this type of polymer HDPE.

BGS, Biogeoscience Institute, University of Calgary; MEYS, Ministry of Education, Youth and Science; MSMT-7778/2014, National Landcare Programme; LO1303, National Landcare Programme; CEBIA-Tech, ERDF, European Regional Development Fund; CZ.1.05/2.1.00/03.0089, ERDF, European Regional Development Fund

TBU in Zlin [IGA/FT/2017/010]; Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under project CEBIA-Tech [CZ.1.05/2.1.00/03.0089]