Interestingly, a twofold increase in ethylene per- meability over neat LDPE was obtained for zeolite-filled PE/SEBS. Resulting films containing 10 wt% zeolite had high ethylene permeability ranging from 1,900 to 2,200 cm3 mm m−2 day−1 atm−1, where desirably high oxygen per- meability was also obtained (i.e., 220–600 cm3 mm m−2 day−1atm−1orOTRof5,500–15,000cm3m−2day−1).Re- sults also indicated the films’ permselectivity to ethylene. Zeolite-filled PE/SEBS exhibited a high ratio of ethylene to O2 permeability (α) of 6–7, where the α values of LDPE and other polyolefins were reported to be approximately 1.5–2.0 (Wang et al., 1998).