Surface properties of electron irradiated polyamide 6,6

Hardness and wear properties of the electron irradiated polyamide 6,6 were evaluated under electron beam irradiation. Samples of polyamide 6,6 without additives, for the mechanical tests were injection-molded. These samples were irradiated with electrons at a dose rate of 2.42 kGy/s and the doses were 70, 100, 150, and 200 kGy. Three sets of samples were analyzed. One set of non-irradiated and irradiated specimens and two other sets with non-irradiated and irradiated samples that were immersed, during six months, in petroleum and sea water separately were studied in order to evaluate the crazing effect produced by these liquids. The experimental results have shown that the ionizing radiation, in the range from 70 to 200 kGy, increases the hardness resistance and reduces strongly the abrasion loss. The crazing effect produced by seawater and petroleum was mainly observed on the non-irradiated samples and also that seawater was more aggressive than petroleum on the surface structure of polyamide 6,6. Additionally, over a dose of 70 kGy, the crazing effect of both liquids was completely eliminated. (author)