STRUCTURAL INVESTIGATION OF HYDRATE COMPOUNDS OF THE TETRAISOAMYLAMMONIUM FORM OF POLYACRYLATE ION EXCHANGE RESINS. CRYSTAL STRUCTURE OF A CLATHRATE HYDRATE OF LINEAR TETRAISOAMYLAMMONIUM POLYACRYLATE
D. V. Soldatov, K. Suwinska, I. S. Terekhova, A. Y. Manakov
Keywords: polymer hydration, two-component system, inclusion compounds, polymeric guest, crystal structure
Pages: 741-747
Abstract
A polyhydrate of the tetraisoamylammonium salt of linear (uncrosslinked) polyacrylate (~25 monomeric units in the polyacrylate chain) is described and compared to polyhydrates of cross-linked tetraisoamylammonium polyacrylates (0.5-3% of cross-linking with divinylbenzene or divinylsulfide). Powder X-ray diffraction reveals that the polyhydrate containing a linear polyacrylate molecule has the same structure (hexagonal, a = 12.26 Å, c = 12.71 Å at 3°C) as polyhydrates of the cross-linked polyacrylate molecules. A single crystal of the polyhydrate obtained from an aqueous solution of linear tetraisoamylammonium polyacrylate is studied by X-ray diffraction at -173°C. The structure is hexagonal; space group P-6m2; the polyhydrate framework is a slightly distorted variant of the hexagonal structure-I of clathrate hydrates.
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