Polymer(Korea), Vol.23, No.5, 755-762, September, 1999
수용액중에 Poly(N-isopropyl acrylamide-co-acrylic acid)의 담점에 미치는 Poly(ethylene oxide)의 영향에 관한 연구
Effect of Poly(ethylene oxide) on the Cloud Point of Poly(N-isopropyl acrylamide-co-acrylic acid) in Aqueous Solution
E-mail:
초록
온도/pH 감응성 공중합체인 poly(N-isopropyl acrylamide-co-acrylic acid)[poly(NP-AAm-co-AAc)]를 단량체 N-isopropyl acrylamide (NIPAAm)과 acrylic acid(AAc), 개시제 2,2-azobisiobutyronitril (AIBN)를 사용하여 dioxane 용매 속에서 라디칼 중합에 의해 합성 하였다. 이때 공중합체 내 AAc의 성분이 10, 20, 30, 40, 50 mol%가 되도록 합성하여Trhm 수용액상에서 poly(NIPAAm-co-AAc)의 담점 (cloud point, CP)에 미치는 분자내 또는 분자간 수소결합의 영향을 poly(ethylene oxide) (PEO)를 선택하여 pH 2.0-7.4의 범위에서 조사하였다. PEO의 분자량은 4 × 102, 6 × 103, 1 × 104, 1 × 105, 1 × 106인 것을 선택하여 사용하였고 담점은 자외선 분광광도측정접을 이용하여 측정하였다. 수용액상에서 poly(NIPAAm-co-AAc)의 담점은 pH, 공중합체 중의 AAc 함량, PEO의 분자량에 큰 영향을 받았다. 또한, pH 2.0, 3.0, 5.0, 7.4에서는 PEO의 첨가가 poly(NIPAAm-co-AAc)수용액의 담점에 큰 영향을 미치지 않았으나 pH 4.0DPTJSMS PEO (M.W : 1 × 106)가 첨가된 poly(NIPAAm-co-AAc) 수용액의 담점은 PAAc와 PEO 사이의 분자간 수소결합에 의해 PEO가 첨가되지 않은 경우보다 온도에서 나타났다.
Temperature/pH sensitive copolymers were synthesized by free radical polymerization of N-isopropyl acrylamide(NIPAAm) and acrylic acid (AAc) in dioxane using 2,2-azobisisobutyronitrile (AIBN) as an initiator. The poly(N-isopropyl acrylamide-co-acrylic acid)s[poly(NIPAAm-co-AAc)s] were prepared by varying molar percentage of AAc in the copolymers. The influence of inter-and intra-hydrogen bonding on the clound points(CPs) of aqueous poly(NPAAm-co-AAc) solution was investigated in the pH range of 2.0∼7.4, making use of poly(ethylene oxide) (PEO). The molecular weights of used P대 were 4 × 102, 6 × 103, 1 × 105, 1 × 106, respectively, and the CPs were determined by UV/visible spectrophotometry. The CPs of the aqueous poly(NIPAAm-co-AAc) solutions were affected by pH, AAc content, and molecular weight of PEO. At pH 4.0, CP of the copolymer containing PEO(M.W.: 1 × 106)was higher than those of the copolymer itself due to intermolecular hydrogen bonding between PAAc and PEO.
Keywords:temperature/pH sensitive polymer;inter-and intramolecular hydrogen bondings;cloud point;lower critical solution temperature(LCST)
- Bae YH, Okano T, Kim SW, J. Polym. Sci., 28, 923 (1990)
- Dong LC, Hoffman AS, J. Control. Release, 4, 223 (1986)
- Bae YH, Okano T, Kim SW, J. Control. Release, 9, 271 (1989)
- Frietas RFS, Cussler EL, Chem. Eng. Sci., 42, 97 (1987)
- Heskins M, Guillet JE, J. Macromol. Sci.-Chem., A2(8), 1441 (1986)
- Hoffman AS, Afrassiabi A, Dong LC, J. Control. Release, 4, 213 (1986)
- Beltran S, Baker JP, Hooper HH, Blanch HW, Prausnitz JM, Macromolecules, 24, 549 (1991)
- Dong LC, Hoffman AS, J. Control. Release, 15, 141 (1991)
- Feil H, Bae YH, Feijen J, Kim SW, Macromolecules, 25, 5528 (1992)
- De Rossi D, Kajiwara K, Osada Y, Yamauchi A, "Polymer Gels," Plenum, New York (1991)
- Dusek K, "Responsive Gels: Volume Transitions I, II; Advances in Polymers Science," vol. 109, p. 110, Springer Verlag, Berlin (1993)
- Taylor LD, Cereukowski LD, J. Polym. Sci., 13, 2551 (1975)
- Winnik FM, Ottaviani MT, Turro NJ, Macromolecules, 25, 6007 (1991)
- Schild HG, Tirrell DA, J. Phys. Chem. Int. J. Pharm., 22, 207 (1984)
- Schild HG, Tirrell DA, Langmuir, 6, 1676 (1990)
- Cho CS, Jung JH, Sung YK, Lee YM, Makromol. Chem. Rapid Commun., 15, 727 (1994)
- Yoo MK, Sung YK, Cho CS, Lee YM, Polymer, 38(11), 2759 (1997)
- Yoo MK, Sung YK, Lee YM, Cho CS, Polymer, 39(16), 3703 (1998)
- Yoo MK, Sung YK, J. Korean Chem. Soc., 42, 84 (1998)
- Chen GH, Hoffman AS, Nature, 373(6509), 49 (1995)
- Zezin AB, Kargin VA, Vysokomol. Soyed., A14, 772 (1972)
- Bokias G, Staikos G, Iliopoulos I, Audebert R, Macromolecules, 27(2), 427 (1994)
- Antipina AD, Varanovskii VY, Pavisov IM, Kabanov VA, Vysokomol. Soedin. Ser. A, 14, 941 (1972)
- Antipina AD, Varanovskii VY, Pavisov IM, Kabanov VA, Vysokomol. Soedin. Ser. A, (translated in Polym. Sci. USSR(Engl. Transl), 14, 1047 (1972)
- Ikawa T, Abe K, Honda K, Tsuchia E, J. Polym. Sci. A: Polym. Chem., 13, 1505 (1975)
- Oyama HT, Tang WT, Frank CW, Macromolecules, 20, 474 (1987)
- Feil H, Bae YH, Jeijen J, Kim SW, Makromol. Chem. Rapid Commun., 14, 465 (1993)