Studies　were　made　on　preparation　of　the　cation-exchange　membranes　obtained　by　pre-irradiation　grafting　of　acrylic　acid　(AA)　and　sodium　styrene　sulfonate　(SSS)　onto　high-density　polyethylene　(HDPE),　and　its　properties　such　as　swelling　behavior　and　electric　resistance　were　measured　as　a　function　of　ion-exchange　capacity　(IEC).　Thermal　and　chemical　stability　was　also　investigated.　These　properties　were　found　to　be　mainly　dependent　on　IEC.　The　grafted　membranes　possessed　good　electrochemical,　thermal　and　chemical　properties,　and　were　found　to　be　acceptable　for　practical　use　as　cation-exchange　membranes.　(C)　2004　Elsevier　Ltd.　All　rights　reserved.