Dicyandiamide, chemically named dicyandiamide (abbreviated as DICY or DCD), has the chemical formula C₂H₄N₄ and a molecular weight of 84.08. Dicyandiamide is a white prismatic crystalline powder, non-flammable, with a density of 1.404 g/cm³ and a melting point ranging from 208 to 212 °C. Physical Properties The solubility of dicyandiamide in water at 13 °C is 2.26%, but it has a higher solubility in hot water. It is soluble in ethanol, acetone, liquid ammonia, and dimethylformamide, but insoluble in diethyl ether and benzene. When the temperature of the aqueous solution reaches 80 °C, dicyandiamide will gradually decompose and release ammonia gas. Preparation Method Dicyandiamide is mainly synthesized by the addition of two aminocyanides. The specific production method involves hydrolyzing calcium cyanamide (lime nitrogen) with water, filtering off calcium hydroxide, and then introducing carbon dioxide to remove calcium, obtaining a cyanamide solution. Polymerization occurs under weakly alkaline conditions, and by controlling the temperature and pH value, followed by cooling crystallization, separation, and drying, the finished product of dicyandiamide can be obtained. Application Fields Chemical Industry Field: Dicyandiamide is widely used as a raw material for guanidine salts and melamine derivatives. It can react with acids to produce various guanidine salts; reacting with phenyl cyanide yields phenylmelamine, which is an intermediate for coatings, laminates, and molding powders. Dye Fixing Agent: The dicyandiamide resin prepared by reacting with formaldehyde is used as a dye fixing agent. Agriculture: Dicyandiamide compound fertilizers can control the activities of nitrifying bacteria, regulate the conversion rate of nitrogen fertilizers in the soil, reduce nitrogen loss, and improve fertilizer utilization efficiency. Pharmaceutical and Fine Chemical Industry: It is used to prepare guanidine nitrate, sulfonamide drugs, etc.; it is also used to prepare thiourea, stabilizers for nitrocellulose, rubber vulcanization accelerators, steel surface hardeners, artificial leather fillers, adhesives, etc.