METHOD OF MODIFICATION OF ULTRAHIGH-MOLECULAR-WEIGHT POLYETHYLENE FOR MANUFACTURE OF JOINT REPLACEMENTS WITH INCREASED LIFETIME

摘要

The solution concerns the method of modification of ultrahigh-molecular-weight polyethylene increasing the lifetime of joint replacements characterized in that the polymer is irradiated in inert atmosphere with Ϝ-rays at dose rates 0.25 kGy/h - 10 kGy/h for 4-220 h or with accelerated electrons at dose rates at least 1200 kGy/h - 12000 kGy/h for at least 12 s and 10 min at the maximum, the total irradiation dose ranging from 40 IcGy to maximum 200 kGy and the thus irradiated ultrahigh-molecular-weight polyethylene is subsequently heated at 90- 200 0C for 5 min - 10 h in inert atmosphere and then continually cooled at a maximum rate of 20 °C/min.