Abstract: Morphology of crystalline polyethylene (PE) irradiated under ⁶⁰Co γ-ray has been investigated by the high-resolution solid-state ¹³C NMR. It is revealed that crystalline phases with lamella, rubbery amorphous phase and their interphase in PE behaved differently to the radiation in the dose range of 75-520 Mrad. The relexation parameters of T_2C and line width were determined for different phases. Their relationship with the radiation is discussed. The phenomena of cross-linking, damage, phase transition and transition of crystal mode in different phases of PE after radiation has been observed, which offer a new proof about mechanism and effect of radiation on PE by the ¹³C NMR.

Key words: High-resolution solid-state ¹³C NMR, Magic-angle sample spinning, Cross-polarization, Radiation effect on crystalline PE, Interphase