幾丁聚醣對人體有生物、血液相容性且無毒性的特性;丙烯酸單體則為生物相容、生物可分解之物質，而接枝共聚合反應則是材料改質的主要技術之一，經常應用於高分子材料及生醫材料等方面。本文利用丙烯酸接枝於中去乙醯度幾丁聚醣(CS45)製成幾丁聚醣-聚丙烯酸接枝共聚合物，探討改變反應溫度、硝酸鈰銨濃度、丙烯酸/幾丁聚醣比例對共聚合產物接枝百分率的影響。實驗結果顯示最佳反應條件為硝酸鈰銨濃度(Ce^(+4))0.14M、反應溫度60℃、丙烯酸單體(AA)/CS45比例為10，依此配方所得最佳接枝百分率為322％。取用最佳配方產物經過適當水解，製得CS45-g-PAA吸附劑，應用於吸附水溶液中之巴拉刈。吸附等溫線結果顯示，Langmuir模式較Freundlich模式更能描述此吸附劑對於巴拉刈的吸附行為，經計算後單層飽和吸附量(Monolayer adsorption capacity) q_m為1127 mg/g-吸附劑，此一結果顯示CS45-g-PAA吸附能力高於近幾年現有文獻，表示此新型吸附劑在吸附水中巴拉刈具有極大潛力。 It is well known chitosan is a biological, blood compatibility and non-toxic material from humans. In our work, graft copolymerization has been weed to prepare the graft copolymer of acrylic acid (AA) and middle deacetylation chitosan (CS45).(AA) was grafted on CS45 (CS45-g-PAA) using graft copolymerization with ammonium cerium nitrate as the initiator. The effects of concentration of initiator, reaction temperature, and AA/CS45 ratio of copolymerization initiator on the grafting reaction were investigated. The results showed that the optimum reaction conditions were [Ce^(+4)] 0.14M , reaction temperature 25℃,and AA/CS45 ratio of 10. The highest grafting percentage was 322% .A representative CS45-g-PAA was hydrolyzed to a salt type adsorbent and applied to the adsorption of paraquat. The adsorption equilibrium data correlate more closely with the Langmuir isotherm than with the Freundlich isotherm. The maximum adsorption capacity of CS45-g-PAA is 1127 mg/g-adsorbent for the paraquat. This results show higher adsorption capacity of CS45-g-PAA than the other works in recent years. The result suggest that CS45-g-PAA has potential use as a paraquat adsorbent.