GB907105A - New polymers having azo-links - Google Patents

Abstract

A polymer is prepared having a molecular structure containing a repeating unit comprising two benzene nuclei directly connected to each other and each carrying as a substituent the group -N=, adjacent units being connected together via the -N= groups by means of -N=N- linkages. The -N= units and -N=N- linkages include <FORM:0907105/IV(a)/1> units and <FORM:0907105/IV(a)/2> linkages. The repeating units may be of the naphthalene or diphenyl types. The polymers may be prepared by (a) oxidizing suitable compounds containing amine groups (b) reducing suitable compounds containing nitro groups or (c) treating a benzo (c) cinnoline with a hydrogen halide whereby the intramolecular -N=N- bonds are severed and adjacent benzo (c) cinnoline residues are linked together by the formation of intermolecular -N=N-linkages. In the examples, the polymers are prepared by (1) reducing 4,5-dinitroacenaphthene with sodium hydroxide in ethanol (2) reducing 1:8-dinitronaphthalene with sodium sulphide in ethanol (3) reducing 2:6:21:61-tetranitrodiphenyl (a) with lithium aluminium hydride, (b) with sodium amalgam and ethanol and (c) with sodium sulphide and alkaline ethanol and (4) the reaction of 1:10-dimethyleneoxy (c) cinnoline with hydrobromic acid. In oxidizing suitable compounds containing amino groups, a suitable oxidizing agent is peracetic acid. The polymers have a high degree of insolubility and are high temperature resistant which makes them suitable as plastic coatings for missiles and high speed aircraft and as linings for fire-bricks; they may be made to contain chelate rings and can therefore be used to separate small quantities of specific metals; they may also be used as dyestuffs as they are coloured.