12 CYANAMID — MANUFACTURE, CHE:MISTRY AND USES 



formed, the most important of which are, the polymer 



N 



^\ 



Tricyantriamide or Melamine H^N — C C — NH2, and Me- 



I 11 

 N N 



^/ 

 C 



I 



lam, CgHjNjj, and Mellon, C5H3N9. Ammonia is evolved 

 during the formation of these bodies. By the action of super- 

 heated steam the conversion of cyanamide to ammonia is 

 almost quantitative. 



Action of Acids.^ — Cyanamide reacts readily with acids ; with 

 nitric acid forming urea nitrate (95 per cent, conversion) ; 

 with sulphuric acid and phosphoric acid giving mostly urea, 

 (about 95 per cent, conversion) together with some ammeline, 

 CsNgCNHJpH; ammelide, C3N3(NH,) (OH)^; possibly 

 cyanuric acid, C3N3(OH)3, and some ammonia. 



Cyanamide combines directly with the haloid acids. It com- 

 bines slowly with free HgS, readily with yellow ammonium 

 sulphide, with formation of thio-urea. Thio-urea is also 

 formed by the action of thioacetic acid on cyanamide in 

 alcoholic solution. Acetic acid produces principally ammo- 

 nium acetate (about 80 per cent, conversion) and some urea. 



Action of Alkalies.=^— The strong alkalies KOH or NaOH 

 in aqueous solutions produce almost entirely urea, with no 

 trace of dicyandiamide ; weak alkalies, NH4OH or MgO, pro- 

 duce dicyandiamide almost exclusively at first, and then 

 ammonia. CaO, however, produces a mixture of urea, dicyan- 



diamide, ammeline, amidodicyanic acid ( O : C<^ ) ,. 



^ ^NH — CN^ 



ammonia and other bodies. 



^ Ulpiani, Gas Chim., Ital. II, No. 4, 358-417. 

 '^ Beilstein's Handbuch der Organische Chemie. 



