Atactic polypropylene samples were preirradiated with Co⁶⁰ radiation source(10000 curie) at -78℃ in air atmosphere, and then subjected to thermal graft copolymerization of styrene at 80~110℃. The homopolystyrene contained in the grafted product was extracted with methyl ethyl ketone solvent, and the centrifugal method was employed to determine the graft%. The results showed that the graft% was directly proportional to the polymerization time and the grafting rate was increased with the polymerization temperature. The overall activation energy of this graft copolymerization was determined to be 16.8 kcal/mole. From the relationship between grafting rate and dose, grafting rate was proportional to 1.03 order of the dose.

Co⁶⁰(10000 curie)을 방사선원으로 하여 -78℃, 공기존재하에서 APP를 전조사시킨 후 styrene과 80~110℃에서 열중합시켰다. Graft생성물 속에 포함되어 있는 homopolystyrene을 methyl ethyl keton을 용매로 사용하여 추출하였으며 graft%는 원심분리법을 이용하여 결정하였다. 그 결과 중합시간에 따라 graft%는 1차적으로 증가하였고 중합온도가 증가함에 따라 graft속도가 증가하였다. 또한 graft중합에 요하는 overall activation energy가 16.8kcal/mole임을 알았으며 선량과 graft속도의 관계로부터 graft속도는 선량의 1.03승에 비례함을 알았다.