The effect of various doses Co-60 radiation source on the thermal and mechanical properties of low density polyethylene

Though they can be used in the industry by their own, polymers are generally used by adding various additives to strengthen their various properties. Many of these additives will serve without joining the structure of the polymer but some additives contribute by changing the structure, thus the physical properties of the polymer. According to literature, radiation are known to cause cross-linking between polyethylene molecules. In this study 10,30,50,70,100 kGy doses radiation is implemented to samples of polyethylene from the source Co-60 . In the present study, thermal properties (DSC) and mechanical properties(tensile strength at yield, tensile strength at break, elongation at break) to investigate the effect of irradiation on, and the calculations were analyzed in detail. Melt flow rate results analyzed , samples of polyethylene melt flow have shown a serious decline due to the increased radiation dose rates. Mechanical analysis analyzed, polyethylene samples? tensile strength at yield and tensile strength at break was observed a steady increase in values until 70 kGy. When applied radiation doses from 70 to 100 kGy, there is a roll-off rate in these values. There is a distinct decrease in elongation at break values of the samples. This situation has shown us that increase in the amount of radiation applied with increase in the mechanical properties caused cross-linking namely friableness the polymer structure. For each sample was applied to the amount of Co-60 radiation DSC analysis of the samples analyzed ,the melting and crystallization temperatures observed to be close proximity. On the other hand released to Co-60 radiation source, Depending on the increasing radiation dose levels the samples of PE melting enthalpy, crystallization enthalpy and crystallization rate values first increased up to 70 kGy; as to radiation doses from 70 to 100 kGy in the melting enthalpy, crystallization enthalpy and the crystallization rate values have observed a decrease depend on the increased radiation dose values. Looking at the results of Tg, F2-21T and F5-21T AYPE samples imposed upon increasing radiation dose increased mass loss temperature is seen that the sample of I22-19T imposed upon radiation dose mass loss temperature rise hardly occurred. The SEM images showed that with the radiation dose applied almost all the samples increased surface roughness. Key words: Cross-linking, melt flow rate, low density polyethylene, mechanical tests, thermal analysis