Supramolecular Structure and Mechanical Characteristics of Ultrahigh-Molecular-Weight Polyethylene-Inorganic Nanoparticle Nanocomposites

We investigated the mechanical properties and structure of polymeric nanocomposites (PNCs) with an ultrahigh-molecular-weight polyethylene (UHMWPE) matrix and aluminum and silicon oxide and nitride nanoparticle (NP) fillers. Mixing with a paddle mixer or by joint mechanical activation in a planetary mill was used for the PNC preparation. Joint mechanical activation afforded PNCs with better mechanical properties than paddle mixing. Scanning electron microscopy suggested that the poorer mechanical properties can be attributed to the disordered regions and imperfect spherulites in the PNC supramolecular structure arising from paddle mixing. The better mechanical properties observed with joint mechanical activation may derive from the uniform NP distribution in the polymer matrix and absence of disordered regions.