Photochemical nanomodification of polymer surfaces: Aerospace applications

Polymers are widely used in the space sector since the first launch in the 1960’s. Their specific characteristics make them one of the most important and most used materials. Hence the necessity of understand, comprehend and master their science and the characterization they are suitable to accept. This work studies the effect of high intensity UV light on the surface of a polymer with the objective of changing the surface roughness characteristics to achieve a level of boost dyeability (either through a pre-primer paint layer or directly painting) and reflexivity of Polypropylene (PP). This change must be achieved in micro-nano scale, and thus keeping the same initial appearance at first glance. The main reason to perform this study is that when a polymer is used for space applications it has to resist very hard conditions such as UV, Atomic oxygen, XRay... PP, itself, is not a common polymer used for space applications. However if the interaction between the UV light and the surface is understood and the result is the desired, changes in the roughness at nano or micro level and the surface activation, it could be found a space application, direct o indirect, for this kind of polymer. The exposition is performed with a high intensity UV lamp, controlling the time and varying the distance between the source and the sample. For the surface analysis, when measuring the surface roughness average, before and after the UV treatment, it was used an interferometric microscope and when it was just needed an image of the surface it was used an optical microscope. The reflexivity study is done with an UV-Vis-NIR spectrometer. The result obtained is that the proposed UV treatment gives to this PP polymer the modification necessary to increase the surface roughness and the surface activation in such a manner that improves the dyeability tests. This corresponds to an improvement of the coating characteristics of the PP, a polymer very difficult to attach any kind of particle, either chemically or mechanically; however is an interesting polymer in many fields due to its good mechanical characteristics and its economic ratio. Consequently the procedures used in this project may be used to be able to apply a coating to a PP based application. vi Photochemical nanomodification of polymer surfaces: Aerospace applications This Page Intentionally Left Blank Photochemical nanomodification of polymer surfaces: Aerospace applications vii