Dicyandiamide Property

Melting point:

208-211 °C (lit.)

Boiling point:

144.35°C (rough estimate)

Density 

1.40

vapor pressure 

0.001Pa at 20℃

refractive index 

1.6260 (estimate)

storage temp. 

2-8°C

solubility 

H₂O: 0.1 g/mL, clear

pka

0.73±0.70(Predicted)

form 

Crystalline Powder

color 

White

Water Solubility 

32 g/L (20 ºC)

Merck 

14,3092

BRN 

605637

Stability:

Stable. Incompatible with strong acids, strong oxidizing agents, strong bases.

InChIKey

QGBSISYHAICWAH-UHFFFAOYSA-N

LogP

-1 at 20℃

CAS DataBase Reference

461-58-5(CAS DataBase Reference)

NIST Chemistry Reference

Dicyandiamide(461-58-5)

EPA Substance Registry System

Dicyanodiamide (461-58-5)

Safety

Hazard Codes 

Xn,T

Risk Statements 

20/21/22-43-36/38-25

Safety Statements 

22-24/25-45-36-3

RIDADR 

UN 2811 6.1 / PGIII

WGK Germany 

1

RTECS 

ME9950000

TSCA 

Yes

HS Code 

29262000

Hazardous Substances Data

461-58-5(Hazardous Substances Data)

Toxicity

LD50 orally in Rabbit: > 5000 mg/kg LD50 dermal Rabbit > 2000 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Hazard statements

H411Toxic to aquatic life with long lasting effects

Precautionary statements

P273Avoid release to the environment.

P391Collect spillage. Hazardous to the aquatic environment

P501Dispose of contents/container to..…

Dicyandiamide Chemical Properties,Usage,Production

Chemical Properties

white powder

Uses

Dicyandiamide is used in the synthesis of barbiturates. It is used as a stabilizer of ammonium dinitramide melt. It is used as hardener.

Uses

Dicyandiamide is a guanidine derivative used in the synthesis of barbiturates,it is also used in the plastics industry (manufacture of melamine).

Uses

In the plastics industry (manufacture of melamine). In the pharmaceutical industry (barbiturates, guanidine derivatives).

Production Methods

Dicyanodiamide is manufactured by dimerization of cyanamide in aqueous solution. The 25% cyanamide solution produced is adjusted to pH 8–9 and held at approximately 80C for 2 h to give complete conversion. The hot liquor is filtered and transferred to a vacuum crystallizer, where it is cooled. The crystals or dicyanodiamide are separated in continuous centrifuges and passed to rotary driers. In 1990, the total worldwide production of dicyanodiamide was about 30,000 tons.

Application

Dicyanodiammonia, abbreviated as dicy or DCD. It is an organic substance with the chemical formula of c2h4n4. It is a dimer of cyanamide and a cyano derivative of guanidine. Chemical formula c2h4n4. White crystalline powder. Soluble in water, alcohol, ethylene glycol and dimethylformamide, almost insoluble in ether and benzene. Stable when dry. It is a guanidine in which one of the amino hydrogens of guanidine itself is substituted by a cyano group. It is used in the manufacture of fertilizers, pharmaceuticals, explosives, oil well drilling muds, and dyestuffs. It has a role as a curing agent, a flame retardant, a fertilizer, an explosive and a nitrification inhibitor. It is a member of guanidines and a nitrile. The application of nitrification inhibitors has been used as a strategy to promote N utilization efficacy and reduce N2O emissions in paddy Dicyandiamide (DCD) as a widely used nitrification inhibitor inhibits the activity of ammonium-oxidizing bacteria which results in longer ammonium retention and reduces the production of NO2?in soils. DCD efficacy was found to be related to DCD concentration, temperature, moisture, pH, and organic matter content. Studies have shown that leaching DCD from agricultural soils into aquatic ecosystems can strongly change the community composition of benthic stream bacteria and algae and influence stream nutrient cycling stoichiometry. Literature on the mechanisms and benefits of nitrification inhibitors is extensive but there are very few studies focused on the influence of DCD application on other microbes in paddy system.

Definition

ChEBI: Cyanoguanidine is a guanidine in which one of the amino hydrogens of guanidine itself is substituted by a cyano group. It is used in the manufacture of fertilizers, pharmaceuticals, explosives, oil well drilling muds, and dyestuffs. It has a role as a curing agent, a flame retardant, a fertilizer, an explosive and a nitrification inhibitor. It is a member of guanidines and a nitrile.

General Description

Dicyandiamide is commonly used for the curing of epoxy resins. It is a nitrification inhibitor that is said to be capable of reducing nitrate (NO^3-) leaching and nitrous oxide (N₂O) emissions from grazed pasture soils.

Flammability and Explosibility

Non flammable

Synthesis

The calcium hydrogen cyanide suspension obtained from the hydrolysis of calcium cyanamide is filtered under reduced pressure to remove the calcium hydroxide filter residue, and then carbon dioxide is introduced into the filtrate to precipitate the calcium in the form of calcium carbonate to obtain the cyanamide solution. It is polymerized under alkaline conditions, then filtered, cooled, crystallized, separated and dried to obtain dimer cyanamide. The temperature at the maximum rate of dicyandiamide formation is related to pH: pH is 9.7 at 50 ℃; PH 9.1 at 80 ℃; The pH is 8.8 at 100 ℃. After controlled polymerization under these conditions, the finished dicyandiamide is obtained by cooling, crystallization, separation and drying. The content of dicyandiamide in industrial products is 99%, and 4239kg of lime nitrogen (more than 21% nitrogen) is consumed per ton of products.

Purification Methods

Recrystallise cyanoguanidine from water or EtOH. [Beilstein 3 IV 160.]