Role of embedded carbon particles on the morphology, microstructure and transport properties of sintered ultra-high molecular weight polyethylene

Selected ultra-high molecular weight polyethylene (UHMWPE) samples extracted from controlled positions along a representative reel from which ski bases are made were analyzed and compared to each other to test their composition and homogeneity. Scanning electron microscopy shows a UHMWPE matrix in which spherical particles are partly agglomerated and homogeneously distributed. Transmission electron microscopy, besides this, reveals the presence of a minority species, namely plate-like inclusions dispersed throughout the matrix. Raman features are traced back to structurally disordered carbonaceous material, with trigonal bond coordination. Surface electrical resistivity is quite low as compared to typical values for UHMWPE, being critically affected by the amount and spatial distribution of carbon particles. The observed homogeneity of distribution of carbon particles in the matrix is likely to be responsible for its ability to dissipate in an effective way the considerable amount of heat generated during ski gliding on hard, packed snow, thus preventing major structural damage of ski bases.