Ultra high molecular weight polyethylene doped with iron through high energy mechanical alloying

Résumé

Doping polymers with metallic materials can improve significantly its use. Ultra high molecular weight polyethylene is known for its high resistance to abrasion and impact, and also for its friction coefficient, which is significantly lower than that of commercial steel and most polymeric materials. Therefore, this material presents high industrial demand despite its processing difficulty due to its high viscosity. One kind of polymer processing which has been widely used recently is the high energy mechanical alloying. This method provokes significant changes in the material, such as crystalline structure transformation, amorphization, formation of metastable phases, and nanostructuring, among others. In order to investigate the influence of iron dopant in structural characteristics of polymeric matrix, ultra high molecular weight polyethylene were doped with low concentrations (between 0.1 at.% and 1 at.%) of iron using the method of high energy mechanical alloying. The samples composition was characterized by X-Ray Diffraction Mössbauer Spectroscopy. A theoretical molecular modeling was carried out to simulate the iron presence in polymeric cell, which is in good agreement with the experimental results. Therefore, there is evidence that part of the iron promotes a crossed bond between the polymeric chains.

Keywords: Ultra high molecular weight polyethylene (UHMWPE), High energy mechanical alloying, Mössbauer Spectroscopy, structural properties.