| Abstract: | The aging of polyethylene under natural conditions as a function of level of prestress was investigated. The aging process was studied in terms of change in physicomechanical indicators, the optical density in terms of the 1720-cm?1 absorption band, and the temperature at which gas begins to evolve during thermal-oxidizing degradation of polyethylene. It is shown that variation in the strength properties of polyethylene during natural aging is associated with variation in the concentration of broken chemical bonds, and also that prestress in the region "prior to the formation of a neck in the specimen" accelerates, and in the region "after the formation of a neck" slows the process of atmospheric aging. A model that takes into account the effect of internal stress in polyethylene on its aging rate under natural conditions is proposed. |
