Swift heavy ion irradiations of aliphatic polymers

This work allows a general outlook of the irradiation of aliphatic polymers with swift heavy ions. The first stage is devoted to the qualitative and quantitative study of defects created into polyethylene under a high electronic stopping power irradiation. The influence of the chain branching is take in account by the study of polypropylene and polybutene under irradiation. Some mechanisms are proposed to explain the formation of all the detected defects. Under low electronic stopping power irradiations, we develop a simulation which allows to compare the radial extension of the inelastic deposited dose due to atomic recoils with these due to the incident projectile and to secondary electrons of the target. The second stage gives access to the localisation of defects around the ion path by two experimental techniques. Low temperature infrared measurements of irradiated samples permit to discriminate the defects created into the crystalline phase from those of the amorphous phase and give access to their position with respect to the track of the ion. Small angle X scattering measurements are also useful for the determination of the position of defects. In this mind, bromination experiments allow the replacement of unsaturations created under irradiation. We have access to bromine atoms which are easily detectable and so to the position of unsaturations. In these experiments, the parameters of the incident ion are essential: the electronic stopping power must be high enough to obtain a good contrast for the non-brominated sample (track radius) but it mustn't be too high to avoid the creation of too big scattering objects which are not experimentally resolved. (author)