Influence of accelerated ageing conditions on the process of polyolefines degradation

The process of polymers weathering and the methods of polymers weathering and accelerated ageing investigations were characterized. Accelerated ageing tests of polyethylene and polypropylene samples have been done in laboratory conditions. The ageing time (up to 400 h) influence, at various levels of ageing factors: UV radiation intensity (80-190 W/m(2)), temperature (35-55 degreesC) and humidity (30-90%), on the changes of the structures of polymers investigated (shares of carbonyl and olefinic groups from FT-IR spectra - Fig. 1, 2, 4 and 5), on the changes of polymers molecular weights (Fig. 3 and 6, Table 1) and on the changes of mechanical properties during tension (Table 1) has been investigated. The role of a proper selection of a factor of the laboratory ageing test time shortening and possible deceptiveness of a method of radiation intensification in such a test were stressed.