Ultra-high molecular weight polyethylene (UHMWPE) was irradiated with accelerated electrons (1 MeV in air) using high dose rates (> 25 kGy/min) and thin specimens (thickness 1 mm). Parts of the specimens were remelted (200 degrees C for 10 min; 150 degrees C for 0, 2, 10, 30, 60 min). All specimens were stored in nitrogen in the dark at 5 degrees C. Supermolecular structure, extent of crosslinking, oxidative degradation, and macroradical content were studied by a number of methods (SAXS, WAXS, SEM, DSC, FTIR, ESR, TGA, solubility experiments, image analysis). The results obtained with irradiated samples were compared with those obtained with irradiated and remelted samples. It was confirmed that crosslinking predominates over chain scission at very high dose rates, even if the irradiation is performed in air. Discrepancies concerning supermolecular structure changes in UHMWPE after irradiation and thermal treatment, found in various studies in the literature, are discussed. A simple model, which describes and explains all supermolecular structure changes, is introduced. An effective way of eliminating residual macroradicals in UHMWPE is proposed.

• MeSH
• Equipment Failure Analysis MeSH
• Biocompatible Materials chemistry   radiation effects   MeSH
• Calorimetry, Differential Scanning MeSH
• Electrons MeSH
• Financing, Organized MeSH
• Humans MeSH
• Microscopy, Electron, Scanning MeSH
• Molecular Structure MeSH
• Oxidation-Reduction MeSH
• Polyethylenes chemistry   radiation effects   MeSH
• Surface Properties MeSH
• Joint Prosthesis MeSH
• Solubility MeSH
• Prosthesis Failure MeSH
• Temperature MeSH
• Materials Testing MeSH
• Radiation MeSH
• Check Tag
• Humans MeSH
• Publication type
• Evaluation Study MeSH

• MeSH
• Elastin chemistry   MeSH
• Models, Molecular MeSH
• Oligopeptides chemistry   MeSH
• Peptides chemistry   MeSH
• Protein Structure, Secondary MeSH

• Conspectus
• Veřejné zdraví a hygiena
• NML Fields
• epidemiologie
• veřejné zdravotnictví
• hygiena

• MeSH
• Pediatrics MeSH
• Publication type
• Biography MeSH

• About
• Švejcar, Josef, 1897-1997 Authority

• Keywords
• hygiena - učebnice, lékařství preventivní - učebnice,

• Conspectus
• Lékařské vědy. Lékařství
• NML Fields
• environmentální vědy
• epidemiologie
• infekční lékařství

• MeSH
• Humans MeSH
• Child Development MeSH
• Health Status MeSH
• Air Pollution MeSH
• Check Tag
• Humans MeSH

• MeSH
• Child MeSH
• Health Status Indicators MeSH
• Air Pollution MeSH
• Check Tag
• Child MeSH

• MeSH
• Diagnostic Techniques and Procedures MeSH
• Child MeSH
• Humans MeSH
• Environmental Monitoring MeSH
• Environmental Exposure MeSH
• Air Pollution MeSH
• Check Tag
• Child MeSH
• Humans MeSH

• MeSH
• Child MeSH
• Palatine Tonsil microbiology   MeSH
• Humans MeSH
• Health Status MeSH
• Air Pollution MeSH
• Check Tag
• Child MeSH
• Humans MeSH

• MeSH
• Cell Membrane physiology   MeSH
• Child MeSH
• Animal Experimentation MeSH
• Hemolysis MeSH
• Blood Physiological Phenomena MeSH
• Rats MeSH
• Erythrocyte Count MeSH
• Leukocyte Count MeSH
• Environmental Exposure MeSH
• Health Status MeSH
• Air Pollution MeSH
• Check Tag
• Child MeSH
• Rats MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• environmentální vědy
• chemie, klinická chemie
• hematologie a transfuzní lékařství
• NML Publication type
• závěrečné zprávy