Effect of low doses beta irradiation on thermal, micro and macro mechanical properties of irradiated polypropylene

• Improvement of micromechanical properties of PP radiated by low beta radiation doses was found to be threefold.
• Macromechanical properties of radiated PP was improved by 28%.
• Heat resistance in modified PP was twofold.
• The low radiation doses cause structural changes.
• Low radiation doses cause relative changes in representation of hydroxyl and carbonyl groups.

The influence of beta radiation on the change of structure and selected properties (both mechanical and heat properties) of polymer materials has been proved. Medium and high doses of beta radiation influence both macro-mechanical and thermal properties of polypropylene in a positive as well as negative way. The use of low doses of beta radiation for polypropylene and its influence on the changes of micro, macro mechanical and thermal properties was thoroughly studied. The specimen were produced by injection technology and subjected to low doses of beta radiation of 0, 15 and 33 kGy The changes of structure, micro, macro and thermal mechanical properties were evaluated by FTIR, WAXS, DSC, tensile test, impact test, microhardness test and thermomechanical analysis. The results of measurements showed a considerable improvement (threefold) of micro mechanical properties (microhardness) of low beta radiation doses. It was also proved that macro and thermomechanical properties of polypropylene modified by low beta radiation doses improved.