Dicyandiamide

Product Details

CasNo： 461-58-5

MF： C2H4N4

Appearance： White crystalline powder

Delivery Time： 15 days

Packing： 25kg/bag

Purity： 99.5%

1. Basic Information

• Chemical Name: Dicyandiamide

• Synonyms: Cyanoguanidine, Di cyano diamide, DICY, DCD

• CAS Number: 461 - 58 - 5

• Molecular Formula: C2H4N4

• Molecular Weight: 84.08 g/mol

2. Physical Properties

• Appearance: White crystalline powder

• Odor: Odorless when pure

• Density: 1.40 g/cm³ (at 25 °C)

• Melting Point: 209.5 °C

• Solubility: Partly soluble in water (2.26% at 13 °C, more soluble in hot water). Soluble in liquid ammonia, ethanol, and some polar organic solvents like dimethylformamide. Insoluble in benzene and chloroform, and has very low solubility in diethyl ether (0.01% at 13 °C).

3. Chemical Properties

• Stability: Stable under normal storage conditions when dry. However, when heated to above 250 °C, it decomposes to form melamine and ammonia.

• Weak Basicity: Exhibits weak basic properties and can react with acids to form salts. For example, it can react with hydrochloric acid to form the corresponding dicyandiamide hydrochloride salt.

• Reaction with Formaldehyde: Reacts with formaldehyde to form resins, which are widely used in various applications such as adhesives and coatings.

• Polymerization and Condensation Reactions: Can participate in polymerization and condensation reactions to synthesize other important chemical compounds, such as in the production of nitrogen - containing heterocyclic compounds.

4. Production Process

Dicyandiamide is typically produced through the polymerization of cyanamide in the presence of a base. The general process involves the following steps:

• Cyanamide Preparation: Cyanamide can be obtained from the hydrolysis of calcium cyanamide. Calcium cyanamide is first hydrolyzed in water to form cyanamide and calcium hydroxide. The reaction can be represented as: CaCN? + 2H?O → H?NCN + Ca(OH)?.

• Polymerization: The resulting cyanamide is then polymerized under basic conditions. The reaction temperature and pH are carefully controlled. For example, at 50 °C, the optimal pH for maximum dicyandiamide formation rate is around 9.7; at 80 °C, it is 9.1; and at 100 °C, it is 8.8. After polymerization, the product mixture is filtered to remove any solid impurities, then cooled for crystallization. The crystals are separated and dried to obtain pure dicyandiamide. Industrially, large - scale production often requires strict control of reaction parameters and purification processes to ensure high - quality product output.

5. Quality Specifications

• Purity: Usually available in purities of 99.0% or higher. For high - end applications, such as in the pharmaceutical and electronics industries, purities up to 99.9% can be achieved. High - purity dicyandiamide is crucial to avoid impurities interfering with downstream reactions or product performance.

• Melting Point Range: A narrow melting point range around the standard value of 209.5 °C is an important quality indicator. Deviations in the melting point may suggest the presence of impurities.

• Residual Impurities: Limits are set for residual starting materials, by - products, and heavy metals. For example, heavy metal content should be extremely low, especially for applications in sensitive fields like electronics, where trace amounts of heavy metals can significantly affect the performance of electronic components.

6. Applications

• Industrial Applications

• Epoxy Resin Curing Agent: Dicyandiamide is a commonly used latent curing agent for epoxy resins. It requires relatively high temperatures (150 - 180 °C) or the addition of accelerators for activation. In the electronics industry, it is used in electronic encapsulation to protect sensitive electronic components. In the composites industry, it helps in the formation of strong and durable composite materials, such as in aerospace components and high - performance sports equipment.

• Flame Retardant: As a component of nitrogen - based flame retardants, it is used in plastics, rubber, and other polymer materials. When incorporated into these materials, it can release nitrogen - containing compounds during combustion, which can dilute flammable gases and inhibit the spread of flames, thus enhancing the fire - resistance of the materials.?

• Dye and Pigment Intermediates: It serves as an important intermediate in the synthesis of melamine and nitrogen - containing heterocyclic compounds. These compounds are further used in the production of various dyes and pigments, contributing to the vibrant colors in textiles, coatings, and inks.

• Agricultural Applications

• Slow - Release Fertilizer Additive: Dicyandiamide can be added to fertilizers as a nitrification inhibitor. It suppresses the activity of nitrifying bacteria in the soil, which slows down the conversion of ammonium - nitrogen fertilizers to nitrate - nitrogen. This helps reduce nitrogen leaching and volatilization losses, thereby improving the nitrogen use efficiency in the soil and reducing environmental pollution associated with excessive nitrogen runoff. However, its use also needs to be carefully managed due to potential environmental risks.

• Other Applications

• Pharmaceutical Industry: It is used as an intermediate in the synthesis of certain drugs, such as sulfonamide drugs. In the synthesis process, its chemical structure can be modified through a series of reactions to introduce functional groups required for drug activity.

• Adhesive and Coating Industry: The resins formed by the reaction of dicyandiamide with formaldehyde are used as adhesives, providing good bonding strength in applications like woodworking and paper lamination. In the coating industry, it can be used in powder coatings and dielectric coatings, contributing to the corrosion resistance and electrical insulation properties of the coated surfaces.

• Water Treatment: Can be used as a component in water treatment chemicals, such as in the formulation of corrosion inhibitors or biocides. It may help prevent metal corrosion in water systems and control the growth of microorganisms, ensuring the proper functioning and longevity of water treatment equipment and pipelines.

• Rubber Industry: In the rubber industry, it can be used as a vulcanization accelerator or a stabilizer. As a vulcanization accelerator, it can speed up the vulcanization process of rubber, reducing production time and improving the physical properties of rubber products, such as increasing the tensile strength and hardness of rubber. As a stabilizer, it can enhance the aging resistance of rubber, extending the service life of rubber products.

7. Storage Conditions

• Sealed Storage: Dicyandiamide should be stored in air - tight containers to prevent moisture absorption and oxidation. Moisture can cause hydrolysis over time, affecting its quality.

• Dry Environment: Keep it in a dry storage area with a relative humidity below 60%. High humidity can lead to caking and degradation of the product.

• Ventilated Area: Store in a well - ventilated place to avoid the accumulation of any potentially harmful gases that may be released in case of decomposition. The storage temperature should be maintained at room temperature (15 - 25 °C), away from direct sunlight and heat sources, as high temperatures can accelerate decomposition.

8. Safety Information

• Toxicity: Dicyandiamide is considered to have low toxicity. The median lethal dose (LD??) for mice via oral administration is greater than 4000 mg/kg. However, ingestion of large amounts may still cause discomfort such as nausea, vomiting, and diarrhea.

• Irritation: It may cause mild irritation to the skin and eyes. In case of skin contact, immediately wash the affected area with plenty of water for at least 15 minutes. If eye contact occurs, rinse the eyes thoroughly with water for 15 minutes and seek medical attention.

• Environmental Impact: Although it has low acute toxicity to the environment, its use as a nitrification inhibitor in agriculture needs to be carefully monitored. Uncontrolled release into the environment may have potential impacts on soil microorganisms and aquatic ecosystems due to its effects on nitrogen cycling.

9. Packaging

Typically, dicyandiamide is packaged in 25 - kg multi - layer paper bags or plastic - lined woven bags. For large - volume customers, it can also be provided in bulk bags or containers. The packaging is designed to ensure product integrity during storage and transportation, protecting it from moisture, dust, and mechanical damage.