Effect of the ionizing radiation in polymers

Particularly, the polymers present three main effects when are exposed to radiation: inter crossing or reticulation, degradation or breaking and tolerance. Depending on the polymer structure, of the energy quantity absorbed by mass unit (dose), the concentration and the inter crossing agent dispersion and of the irradiation conditions; inert atmosphere or air and the temperature to which the irradiation is made, some of those effects is favored. The polymers that are used as isolations of cables and electric wires for specific applications require mechanical and electric properties superiors to those of the conventional materials. So, it is desirable that an insulating subjected to the high temperature produced by an electric discharge is not melted, what is associated to an inter crossed structure. Among the years 1983 and 1984, the IAEA advised to the Instituto Nacional de Investigaciones Nucleares (ININ) in diverse uses of the irradiation technology in the polymers area. Starting from then, it is began to research the effect of the gamma radiation in formulations based on polyethylene of low density/copolymer of ethylene vinyl acetate, using trimethylol-propane trimetacrilate like inter cross agent and with conventional preservatives, such as flame dilators, antioxidants, lubricants, etc., used in the cables industry and electric wires. In this chapter the result of the researches realized by the area of the ININ are given. (Author)