The Effect of Electron Beam Radiation on the Molecular Structure of Ultra-high Molar Mass Polyethylene Used for Medical Implants

摘要

Systematic investigations on the influence of electron beam radiation of different dosage on molecular degradation as well as crosslinking of ultra-high molar mass polyethylene containing various amounts of α-tocopherol as stabilizer were carried out in air and an inert nitrogen atmosphere. The samples were analyzed with respect to their content of insoluble crosslinked fraction and the molar mass distribution of the soluble fraction. The extent of crosslinking and degradation is dependend on the absorbed dosage of the radiation. The crosslinking process is favored in nitrogen atmosphere whereas in air molecular degradation is increasing. The extent of crosslinking as well as degradation can be reduced by the addition of α-tocopherol both, in air and nitrogen.