STRENGTH CHARACTERISTIC PROPERTIES OF POLYETHYLENE CROSSLINKED BY RADIATIONAL-CHEMICAL METHOD

摘要

New effects in change of structure and properties of polyethylene treated by electron beam were discovered during elaboration of polymer materials and goods for usage in extreme working conditions. Irradiation was done on radiational-chemical installation on basis of electron accelerator ILU-6 created in Institute of Nuclear Physics. It was fixed that lower limit of temperature at which low density polyethylene is not destroying under impact load (temperature of embrittlement) depends on crosslinking level. This temperature in the initial state is —85℃, and irradiation with dose of 0.4 and 0.1 MGy causes its decrease up to -126℃ and -145℃ respectively. Increase of resistance for impact load at low temperatures was explained by radiation caused increase of share of transit chains which bear load. Formation of such chains can be done in inter-crystallite amorphous regions during process of crosslinking of macromolecules' ends, loops and just existing transit chains. Increase of share of transit chains which are bearing load benefits dissipation of tensions in amorphous- crystallite polymer. Ratio of modules of elasticity of amorphous regions in initial and irradiated samples was used to indicate share of transit chains.