Abstract
The α helices of copoly(butyl-L-aspartate-benzyl-L-aspartate) prepared by substituting some of the benzyl groups in the side chains of poly(β-benzyl-L-aspartate) by butyl groups, were transformed, throughout the entire range of butylation tested, into ω helices with a tetragonal packing when heated up to 140°C. The α–ω transition temperature was about 100°C for copolyaspartates of butylation less than 30% and near 130°C for copolyaspartates of butylation more than 30%. In the case of more than 30% butylation the α–ω transition was furthermore accompanied by a change from the right handed a helix to the left handed ω helix. The α–ω transition resulted in a remarkable change in the magnitude of the dynamic modulus and an exothermic peak. It was concluded that the ω helix of copoly(butyl-L-aspartate-benzyl-L-aspartate) was based on the formation of stacks between benzyl and butyl groups as well as the ω helix consisting of stacks between the benzyl groups of poly(β-benzyl-L-aspartate).
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E. M. Bradbury, A. R. Downie, A. Elliott, and W. E. Hanby, Proc. R. Soc., London, Ser. A, 259, 110 (1960).
E. M. Bradbury, L. Brown, A. R. Downie, A. Elliott, R. D. B. Fraser, and W. E. Hanby, J. Mol. Biol., 5, 230 (1962).
L. Bragg, J. C. Kendrew, and M. F. Perutz, Proc. R. Soc., London, Ser. A, 203, 321 (1950).
D. B. Green, F. Happey, and B. M. Watson, Eur. Polym. J., 6, 7 (1970).
H. Obata and H. Kanetsuna, J. Polym. Sci., A2, 9, 1977 (1971).
H. Kyotani and H. Kanetsuna, J. Polym. Sci., 10, 1931 (1972).
M. Fukagawa, Y. Tsujita, and I. Uematsu, unpublished data.
B. R. Malcolm, Nature, 219, 929 (1968).
B. R. Malcolm, Biopolymers, 9, 911 (1970).
Y. Takeda, Y. Iitaka, and M. Tsuboi, J. Mol. Biol., 51, 101 (1970).
E. M. Bradbury, B. G. Carpenter, and R. M. Stephens, Biopolymers, 6, 905 (1968).
E. M. Bradbury, B. G. Carpenter, and R. M. Stephens, Macromolecules, 5, 8 (1972).
H. Leuchs, Ber., 39, 857 (1906).
P. Doty, S. H. Bradbury, and A. M. Hiltzer, J. Am. Chem. Soc., 78, 947 (1956).
E. M. Bradbury, B. G. Carpenter, and H. Goldman, Biopolymers, 6, 837 (1968).
R. F. McGuire, G. Vanderkooi, F. A. Momany, R. T. Ingwall, G. M. Crippen, N. Lotan, R. W. Tuttle, K. L. Kashuba, and H. A. Scheraga, Macromolecules, 4, 112 (1971).
O. B. Eagar and R. E. Hill, J. Polym. Sci., 8, 1 (1952).
Y. Tsujita and I. Uematsu, Polym. J., 6, 274 (1974).
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Tsujita, Y., Fukagawa, M. & Uematsu, I. The Structure and Properties of Copolyaspartate I. Copoly(butyl-L-aspartate-benzyl-L-aspartate). Polym J 14, 773–779 (1982). https://doi.org/10.1295/polymj.14.773
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DOI: https://doi.org/10.1295/polymj.14.773