GB858041A - Activators for the polymerization of pyrrolidone - Google Patents

Abstract

A process for polymerizing pyrrolidone comprises forming a mixture of monomeric pyrrolidone, a polymerization catalyst therefore and a catalyst activator selected from the group consisting of carbon disulphide, nitrogen dioxide and organic nitrites of the general formula R-O-N=O where R is an alkyl radical containing 1 to 10 carbon atoms, a haloalkyl radical containing 2 to 10 carbon atoms, a nitroalkyl radical containing 2 to 10 carbon atoms, an aralkyl radical containing 7 to 10 carbon atoms or an alkoxyalkyl radical containing 3 to 12 carbon atoms, the molar ratio of catalyst to activator being in the range 1 : 1 to 1 : 200 and the molar ratio of catalyst to pyrrolidone being in the range 1 : 5 to 1 : 280, and subjecting said mixture to a temperature in the range 70 DEG C. to 100 DEG C. until polymerization is complete. Specified catalysts are the alkali metals and the hydrides, hydroxides, oxides, salts and organic compounds thereof. Many organic nitrite activators are specified. The activator may be added to the reaction mixture when the water which may be formed by the addition of the catalyst has been distilled off. The polymerization may be effected by solution, emulsion, suspension or bulk polymerization. In the examples, pyrrolidone is polymerized in the presence of sodium hydride and (II) n-butyl nitrite, (III) nitrogen dioxide and (IV) carbon disulphide.