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High purity Guanidine carbonate synthesis method

Guanidine carbonate is an extremely versatile organic chemical products, it is mainly used in flame retardants, flocculants, foaming agents, synthetic sulfa drugs, etc. Guanidine carbonate is also used as synthetic detergent builders, high-quality cosmetics raw materials.Synthesis of guanidine carbonate is reported by many literatures [1-3] .The main domestic guanidine carbonate production is that molt dicyandiamide and ammonium chloride to generate guanidine hydrochloride, generate free guanidine under the action of the alkali, and then by the reaction of free guanidine and carbon dioxide to produce guanidine carbonate. this route is easy to generate melamine and its dimers, trimers and other impurities because of the high-temperature melting , and the presence of Cl-, Na + in the system is difficult to completely removed , even if the purity is> 99% of guanidine carbonate, its ash content is still up 0.2%, it is difficult to obtain high purity guanidine carbonate. in this paper, cyanamide as raw materials, reacts with carbon dioxide and ammonia in one step synthesis of guanidine carbonate, also known as ash-free guanidine carbonate, and then purify , to obtain a high purity guanidine carbonate, the reaction equation is as follows: 2NH2CN + CO2 + 2NH3 + H20 → [NH2C (: NH) NH2] 2H2CO3 Author: Zhouzhao Liang Xie Jianwei Zhou Xiaohong Jiang Yongqing Author: Zhouzhao Liang, Xie Jianwei (Research Institute of Zhejiang University of West Branch Quzhou 324006) Zhou Xiaohong, Jiang Yongqing (Institute of Fine Chemicals Group Technology Center Juhua Quzhou 324004)

Reference quality standards

[Industry Grade ] Name of Item Technical index Premium grade B product Appearance white crystalline white powder Content of ≥ 99% 98% Ammonium ≤ 0.45% 1.0% Water insoluble matter ≤ 0.2% 0.2% Moisture ≤ 0.2% 0.2% Ash ≤ 0.15% 0.2% Water-soluble test Qualified Qualified PH value (4% 25 ℃) 11.4 11.4 [Pharmaceutical Grade ] Name of Item Technical index Premium grade Appearance white crystals Content ≥ 99% Ammonium salt (with NH4Cl meter) ≤ 0.45% Water insoluble matter ≤ 0.2% Moisture ≤ 0.2% Ash ≤ 0.1% Water-soluble test Qualified PH value (4% 25 ℃) 11.4 Heavy Metal ppm ≤10 Arsenic ppm ≤3

Chemical Properties

white to almost white crystalline powder. Soluble in water, slightly soluble in methanol, almost insoluble in acetone, benzene and ether.

Uses

Guanidine Carbonate is a strong organic alkali. It is used to adjust the pH of a formulation, organic intermediate, soap and cosmetic products.

Application

Guanidine carbonate salt can be used as a reactant for the synthesis of:An oxidizer, guanidinium dinitramide (GDN), by reacting with ammonium dinitramide.Guanidinium cyclopropanecarboxylate by reacting with cyclopropanecarboxylic acid.

Preparation

Synthesis of guanidine carbonate: Melt double cyanide salts and ammonia to generate guanidine salts (guanidine hydrochloride, guanidine nitrate) at 170-230 ℃ . Then make guanidine salt into an alcohol solution, add soda to free guanidine, absorb carbon dioxide to obtain guanidine carbonate.

Hazard

Toxic by ingestion.

Flammability and Explosibility

Nonflammable

Purification Methods

Crystallise it from MeOH. [Beilstein 3 H 86, 3 I 41, 3 II 72, 3 III 161, 3 IV 152.]