Abstract
Copolymerizations of methacrylic acid (MA) and methyl methacrylate (MMA) with 2-vinylpyridine (2VP) were carried out at 60°C with 2,2′-azobis(isobutyronitrile) (AIBN) as the initiator. Monomer reactivity ratios were obtained as r1=0.24 and r2=0.46 for the MA (M1)-2VP (M2) system, and r1=0.46 and r2=1.13 for the MMA (M1)-2VP (M2) system, respectively. The 1:1 copolymers of MA-2VP and MMA-2VP were prepared on the basis of monomer reactivity ratios obtained. Macroscopic and microscopic acid dissociation constants of the 1:1 copolymer of MA and 2VP were determined by pH-titration method. The relative concentrations of respective microscopic forms were calculated using the relation between micro-constants and hydrogen ion concentration. The fraction of the protonated form of the 1:1 copolymer of MA and 2VP, which exists exclusively in the lower pH range, decreases with increasing pH value and fully vanishes at pH=6, while the deprotonated form begins to appear at pH=5. The zwitterionic and neutral molecule forms coexist in the pH 2 to 10 region, and the latter form is predominant regardless of pH value. Macro- and micro-constants were also measured for the systems of the monomer mixture and the homopolymer mixture. Similar pH-distribution curves are obtained for three systems (the 1:1 copolymer, the 1:1 homopolymer mixture, and the 1:1 monomer mixture)
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References
J. T. Edsall and J. Wyman, “Biophysical Chemistry,” Vol. 1, Academic Press, New York, N.Y., 1958, p 477.
D. L. Rabenstein and T. L. Sayer, Anal. Chem., 44, 114 (1976).
R. I. Shrager, J. C. Cohen, S. R. Heller, D. H. Sacks, and A. N. Schechter, Biochem., 11, 541 (1972).
D. L. Rabenstein, M. S. Greenberg, and C. A. Evans, Biochem., 16, 977 (1997).
S. F. Mason, J. Chem. Soc., 674 (1958).
K. Nakamoto and A. E. Martell, J. Am. Chem. Soc., 81, 5857 (1959).
H. Sakurai and T. Ishimitsu, Talanta, 27, 293 (1980).
W. H. Streng, J. Pharm. Sci., 67, 666 (1978).
S. Sugai and K. Nitta, “Kobunshi Denkaishitu,” Kyoritsu Shuppan, Tokyo, 1978, p 41.
H. P. Gregor, L. B. Lutteinger, and E. M. Loebl, J. Phys. Chem., 59, 34 (1955).
M. Nagasawa, T. Murase, and K. Kondo, J. Phys. Chem., 69, 4005 (1965).
M. Nagasawa and A. Holtzer, J. Am. Chem. Soc., 86, 531 (1964).
R. S. Asquith, K. L. Gardner, and K. W. Yeung, J. Polym. Sci., 16, 3275 (1978).
S. Masuda, M. Tsuda, T. Tomida, and M. Tanaka, Chem. Lett., 601 (1994).
T. Kelen and F. Tüdös, J. Macromol. Sci., Chem., A9, 1 (1975).
J. Brandrup and E. H. Immergut, “Polymer Handbook,” 3rd ed, John Wiley & Sons, New York, N.Y., 1989, pp II-268–269.
T. Ishimitsu, H. Hinose, and Y. Fujiwara, Talanta, 26, 67 (1979).
G. E. Clement and T. P. Hartz, J. Chem. Educ., 48, 395 (1971).
H. L. Jung and L. Chang, J. Chem. Educ., 51, 106 (1974).
T. Ishimitsu, S. Hirose, and H. Sakurai, Talanta, 24, 555 (1977).
D. P. Wrathall, R. M. Izatt, and J. J. Christensen, J. Am. Chem. Soc., 86, 4779 (1964).
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Masuda, S., Minagawa, K., Tsuda, M. et al. Microscopic Acid Dissociation of the 1:1 Copolymer of Methacrylic Acid and 2-Vinylpyridine. Polym J 30, 921–924 (1998). https://doi.org/10.1295/polymj.30.921
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DOI: https://doi.org/10.1295/polymj.30.921
