TEMPERATURE-DEPENDENCE OF MOBILITY OF MACROMOLECULES IN RADIATION-CROSS-LINKED POLYETHYLENE

The effect of temperature and dose on the molecular mobility in the am orphous regions of polyethylene was studied using a spin-probe techniq ue. The molecular mobility was characterized by a rotational correlati on time tau(c) of the nitroxyl radical TEMPOL introduced into the poly mer by diffusion from its solution in alcohol. It was shown that the t emperature dependence of this parameter is linear and has an inflectio n in the region 323 - 353 K. The dependence in the low-temperature reg ion is affected by the radiation dose: the higher the dose is, the gre ater the parameter tau(c). The dose and temperature effects on tau(c) were found to be independent of the orientation degree of the polymer.