Observation of salt impurities in ultra-high-molecular-weight polyethylene(UHMWPE)

Different direct molded ultra-high-molecular-weight polyethylene (UHMWPE) s amples have been investigated using reflective light microscopy and scannin g electron microscope techniques (low voltage and variable pressure SEM). O n the surfaces as well as throughout the material a-to the best of our know ledge-unknown type of impurities has been identified. X-ray element analysi s (EDX) was used to characterise these impurities as sodium chloride and po tassium chloride salt inclusions. (C) 1999 Kluwer Academic Publishers.