Non-Specific Routes

Non-Specific Routes.— The preparation of ketone-containing polyamides has been investigated and their properties compared to systems of the normal type i28, 229 These polymers were prepared from hexamethylene diamine and keto-containing dicarboxylic acids and varying amounts of the keto function were introduced at random along the main chain yielding systems having enhanced photochemical lability. 

Chromium-co-ordinated polyamides have been studied and applications evaluated for these extrusion processable materials.  

Polyamide synthesis has also been reported from di-isocyanates and active carbon-hydrogen containing compounds, from bisketenimines and dicarboxylic acids.  

Polycyanamides have been prepared from bis-a-aminonitriles and subjected to thermal cyclization to polyphenylene imidazolones. Similar studies have been made on polythiocyanoamides whose isomerization cyclization has yielded sulphur-containing polyheteroarylenes. 

Fluorine-containing systems with sulphonyl groups in the main chain having flame-retardant properties have also been reported.  

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