Nature Description: White prismatic crystalline powder, non-flammable. Melting point 207-209°C, relative density 1.400 (25/4°C). The solubility in water at 13°C is 2.26%, and it is easily soluble in hot water. When the aqueous solution is above 80°C, it decomposes slowly to produce ammonia. Its solubility in anhydrous ethanol at 13°C is 1.26%, soluble in acetone and liquid ammonia, and hardly soluble in ether and benzene. Dry dicyandiamide is stable in nature.
Production method: Lime nitrogen (calcium cyanamide) and water are hydrolyzed, and the resulting suspended hydrolyzate is filtered to remove calcium hydroxide by cyanamide ammonium chloride, and the filtrate is passed through carbon dioxide to decalcify to obtain cyano-ammonia solution. Then, cyanamide is polymerized under weak alkaline conditions. The temperature at which the dicyandiamide produces its maximum speed is related to the pH: the pH is 9.7 at 50°C; the pH is 9.1 at 80°C; and the pH is 8.8 at 100°C. After controlling the polymerization under these conditions, it is cooled, crystallized, separated and dried to obtain the finished dicyandiamide. The dicyandiamide content of industrial products is 99%, and the consumption of lime nitrogen (21% or more of nitrogen) is 4239kg per ton of product.
Uses: The main uses of dicyandiamide are: (1) As a raw material of guanidine salt and melamine. By reacting dicyandiamide with acid, various phosphonium salts can be produced. The benzoguanamine obtained from the reaction of dicyandiamide and benzonitrile is an intermediate for paints, laminates and molding powders. (2) As a dye fixing agent, dicyandiamide resin obtained by the reaction of dicyandiamide and formaldehyde can be used as a dye fixing agent. (3) Dicyandiamide fertilizer and dicyandiamide compound fertilizer can control the activity of nitrifying bacteria, regulate the conversion rate of nitrogen fertilizer in soil, reduce the loss of nitrogen, and increase the use efficiency of fertilizer. (4) As a fine chemical intermediate. In medicine for the preparation of thorium nitrate, sulfa drugs, etc.; also used to prepare thiourea, nitrocellulose stabilizer, rubber vulcanization accelerator, steel surface hardening agent, artificial leather filler, adhesives and so on. Reaction of dicyandiamide with formic acid provides 5-azacytosine as a pharmaceutical intermediate.
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Shandong Bolode Bio-technology Co., Ltd. , https://www.bldpharma.com