The effects of various amounts of Co-60 radiation polypropylene on mechanic and thermal properties

By treating polymer easily materials of different size and shape can be obtained. These materials can be used in daily life and in any area of industry thanks to its high mechanic resistance, their resistance to chemical materials, low condensation and high temperature and electric resistance features. In addition, though polymer products take part in production by itself they can also be used by adding various additives material. These additives lead to different chemical and physical changes in the structure of polymer. In literature, it is known that when polypropylene interacts with radiation, degradation takes place in the structure of polypropylene. In this study, radiation of 10, 30, 50, 70,100 kGy doses was applied from 60Co source to the samples of polypropylene MH-418, EH-102, EH-251 which have different molecule weight. Melting flow speed of samples, hardness, mechanical analysis (durability of strain in flowing, durability of strain for burst, extension for burst) thermal analysis (DSC, TG) and SEM images were observed. When melting flow index of the samples was examined, it was determined that there was a significant increase in the speed of melting flow in connection with increasing radiation amount. When the mechanical analysis of the samples were examined, there was a significant decrease in resistance of strain for flowing, resistance of strain for burst and extension of burst values. Particularly, as the samples with 100 kGy radiation amount had deformation, there was no reading for the values. When DSC analysis of the samples were examined, depending on the increasing radiation amount, there was a decrease in melting temperature Tm, crystallization temperature Tc, melting enthalpy ?Hf, crystallization enthalpy ?Hc and the rate of crystallization Xc values. It was observed that there was mass loss against heat in TG analysis of samples. Depending on the increasing radiation amount of MH-418 sample there was an %1, %10, %50, %99 increase in mass loss temperature , whereas there was a %1, %10, %50,%99 decrease in mass loss temperature for EH-102, EH-251 samples. When SEM images of samples were examined, radiation of 50 kGy led to roughness on the surface. When the radiation amount was up to 100 kGy, the roughness on the surface decreased significantly Key words: Polypropylene, degradation, radiation, mechanical analysis, thermal analysis, SEM