Grafting　copolymerization　of　styrene　and　acrylic　acid　onto　polypropylene　fabric　had　been　studied　by　using　a　
pre-irradiation　technique.　The　polypropylene　fabric　samples　were　irradiated　by　γ　-ray　and　electron　beam　under　the　conditions　of　air　
and　nitrogen　gas,　respectively.　The　effect　of　absorbed　dose,　monomer　concentration　in　solvent,　reaction　temperature　and　reaction　time　
on　the　degree　of　grafting　were　determined.　The　effects　of　metallic　salts　and　sulphuric　acid　on　the　grafting　yield　of　acrylic　acid　were　
also　examined.　The　samples　irradiated　by　electron　beam　give　a　much　higher　degree　of　grafting　than　those　by　γ　-ray　when　styrene　was　
grafted　to　polypropylene　fabric.　However,　the　grafting　yield　of　acrylic　acid　on　polypropylene　fabric　in　the　presence　of　metallic　salts　
and　sulfuric　acid　showed　the　opposite　results　from　the　case　of　styrene.　This　effect　is　reasonably　interpreted　by　assuming　that　the　
grafting　is　dominated　by　trapped　radicals　and　peroxides　in　pre-irradiated　polypropylene.