Ultrahigh molecular weight polyethylene (UHMWPE) having a low coefficient of friction (CoF), high wearand chemical resistance in harsh environments, is used for fabricating medical products (hip and knee joints, intervertebral discs, plates for maxillofacial surgery, and others). Priority of polymers, in particular UHMWPE to be applied as medical implant materials, is due to their proximity to ...

An early event in the induction of apoptosis is cytochrome c (Cyt c) release from mitochondria. We investigated the involvement of mitochondrial permeability transition (MPT) and mitochondrial swelling in Cyt c release from mitochondria treated with alloxan and/or calcium (Ca). When mitochondria were treated with a high concentration of Ca alone or Ca with alloxan (alloxan-Ca), the MPT was acco...

Polyethylene glycol dinitrates (PEGN) with molecular weights between 400 and 20 000 g·mol-1 were prepared from polyethylene glycols by esterification with nitric acid/sulfuric acid in dichloromethane. The products were characterized by gel permeation chromatography. The yield of PEGN increases with increasing reaction temperature (0-40 °C) however large liberation of nitrogen oxides was observe...

Chromium-vanadium (Cr-V) bimetallic catalysts are prepared by the introduction of vanadium into the Phillips catalyst which is one of the most significant industrial ethylene polymerization catalysts for tuning the Phillips catalyst performances and improving polyethylene properties. In the present work, titanium species were introduced into the fluorine-modified chromium-vanadium bimetallic ca...

Graphene nanoplatelets (GNPs) are added as reinforcement to ultrahigh molecular weight polyethylene (UHMWPE) with an intended application for orthopedic implants. Electrostatic spraying is established as a potential fabrication method for synthesizing large-scale UHMWPE-GNP composite films. At a low concentration of 0.1 wt % GNP, the composite film shows highest improvement in fracture toughnes...

The objective of this study was to assess the suitability of using multidirectional pin-on-disk (POD) testing to characterize wear behavior of retrieved ultrahigh molecular weight polyethylene (UHMWPE). The POD wear behavior of 25 UHMWPE components, retrieved after 10 years in vivo, was compared with 25 that were shelf aged for 10-15 years in their original packaging. Components were gamma ster...

Artificially fabricated surface textures can significantly improve the friction and wear resistance of a tribological contact. Recently, this surface texturing technique has been applied to polymer materials to improve their tribological performance. However, the wear behavior of textured tribo-pairs made of steel and polymer materials has been less thoroughly investigated and is not well under...