Abstract: The effect of sensibilizers and antioxidants on the cross-linking degree in radiation crosslinked polyethylene pipes was investigated. The optimal recipe was obtained as: weight ratio of high density polyethylene/linear low density polyethylene 80/20，sensibilizer M-1 2. 5%，and antioxidant agent 2. 5%。，based on total amount of polyethylene. Since the crosslinking and degradation occurred simultaneously, the tensile strength and elongation at break decreased with increasing radiation dose. However,at 10一15 Mrad these properties were satisfied. The degree of crystallinity showed no change with increasing radiation dose, which indicated that the crosslinking occurred only in amorphous region or interface.

Key words: radiation crosslinking, polyethylene, pipe, sensitizer, antioxidant, crosslinking degree