Micro-hardness of surface layer of irradiated polypropylene

Using high doses of beta radiation for polypropylene (PP) and its influence on the changes of micromechanical properties of surface layer has not been studied in detail so far. The specimens of PP were made by injection moulding technology and irradiated by high doses of beta radiation (0, 33, and 66 kGy). The changes in the microstructure and micromechanical properties of surface layer were evaluated using WAXS and instrumented microhardness test. The results of the measurements showed considerable increase in micromechanical properties (indentation hardness, indentation elastic modulus) when high doses of beta radiation are used