Dissolution and formation of polyacrylonitrile in low-temperature molten salts

The solubility and the polymerization of polyacrylonitrile in low-temperatu re molten salts was investigated. It was found, that the polymer dissolves in eutectic mixtures of molten sodium thiocyanate and potassium thiocyanate (NaSCN/KSCN) as well as in the molten hydrate lithium perchlorate (LiClO4* 3H(2)O). The polymer can be regenerated by cooling the melt or diluting wit h water. The chemical interaction between the molten salt and the polymer w as investigated by C-13-NMR spectroscopy. These measurements show that the dissolution of the polymer in molten KSCN/NaSCN is accompanied by the split ting of the the hydrogen bonds. Starting from acrylonitrile, the formation of polyacrylonitrile by a radical polymerization in a molten salt becomes s uccessful. The polymerization of acrylonitrile in an eutectic mixture of KS CN/NaSCN results in the formation of atactic polyacrylonitrile with high mo lecular weight. (C) 2000 John Wiley & Sons, Inc.