An　interesting　grafting　reactivity　of　electron　beam　preirradiated　polypropylene　(PP)　film　was　found　by　grafting　of　acrylic　acid　(AAc)　and　acrylamide　(AAm)　repeatedly　or　intermittently.　The　preirradiated　PP　film　could　be　grafted　several　times　intermittently　and　the　free　radicals　or　peroxides　on　the　samples　could　be　determined　after　several　times　grafting　reaction.　The　effects　of　storage　time,　reaction　time　and　repeated　reaction　times　on　the　degree　of　grafting　were　investigated.　The　trapped　radicals,　peroxy-radicals　and　peroxides　on　the　preirradiated　and　reacted　PP　films　were　determined　by　using　electron　spin　resonance　(ESR)　and　1,1-diphenyl-2-picryl　hydrazyl　(DPPH),　respectively.　An　interpenetrating　polymer　networks　(IPN)　with　both　temperature　and　pH　sensitive　properties　was　obtained　by　two　times　grafting　of　AAm　and　AAc　onto　preirradiated　PP　film.　(C)　2003　Elsevier　Ltd.　All　rights　reserved.