CARBOHYDRAZIDE POWDER

Simultaneously, Carbohydrazide Powder reduces porous, non-protective red ferric oxide (hematite, Fe2O3) on steel surfaces into a dense, tightly adherent black magnetite (Fe3O4) passivation layer and reduces cupric oxide (CuO) on copper-alloy condenser tubes into protective cuprous oxide (Cu2O), arresting under-deposit pitting corrosion across operating temperatures from below 100 degrees Celsius up to >250 degrees Celsius.
In polymer and coating chemistry, the two terminal nucleophilic hydrazide (-NHNH2) groups of Carbohydrazide Powder react rapidly upon water evaporation with ketone-functionalized latex polymers (such as diacetone acrylamide copolymer emulsions) to form covalent hydrazone (-C=N-NH-C(=O)-) crosslinks at ambient temperature without volatile organic coalescents or isocyanate curatives.
Selecting the appropriate commercial grade of Carbohydrazide Powder requires verifying the active Carbohydrazide assay, residual free hydrazine content (typically <= 50 ppm to <= 200 ppm), moisture / loss on drying, melting range (152 to 154 degrees Celsius), ash / residue on ignition, aqueous solution clarity, and batch Certificate of Analysis.

WHAT IS CARBOHYDRAZIDE POWDER?

Carbohydrazide Powder, known as Karbohidrazid Toz, Karbohidrazit, Karbonik Dihidrazid, or 1,3-Diaminoüre in Turkish, is the symmetrical dihydrazide of carbonic acid, consisting of a central carbonyl group (C=O) flanked covalently by two hydrazinyl (-NH-NH2) functional groups (H2N-NH-C(=O)-NH-NH2, molecular formula CH6N4O, molecular weight 90.085 g/mol). In global chemical inventories and EU REACH registrations, this crystalline organic compound is identified under CAS No. 497-18-7 and EC / EINECS No. 207-837-2.
Structurally, Carbohydrazide Powder is the di-amino analog of urea (CO(NH2)2) in which both amide hydrogens are replaced by terminal primary amino groups, and the carbonic acid homologue of aliphatic dihydrazides such as adipic dihydrazide (ADH). At ambient temperatures, pure Carbohydrazide forms white, odorless orthorhombic or monoclinic prismatic crystals that melt with thermal decomposition at approximately 152 to 154 degrees Celsius.

Carbohydrazide Powder was developed and adopted worldwide primarily to overcome the severe occupational health, flammability, and vapor-exposure hazards of liquid hydrazine (N2H4, CAS 302-01-2) and hydrazine hydrate (CAS 7803-57-8). Whereas liquid hydrazine is a volatile, fuming, flammable liquid classified as a high-consequence carcinogen that requires closed-system vapor containment, Carbohydrazide Powder is a stable, non-volatile, non-flammable crystalline solid at room temperature that can be weighed, dissolved in make-up water tanks, or dry-blended with far lower inhalation risk while still delivering volatile, zero-solids oxygen scavenging and magnetite passivation inside steam boilers.

Buyers and formulators must strictly distinguish Carbohydrazide Powder (the >= 98%–99% active solid crystalline raw material, CAS 497-18-7) from dilute aqueous Carbohydrazide boiler-treatment solutions (typically supplied at 5% to 12% w/w active Carbohydrazide in water, sometimes catalyzed with 0.05%–0.2% hydroquinone), from Hydrazine Hydrate (N2H4·H2O, CAS 7803-57-8), and from Adipic Dihydrazide (ADH, C6H14N4O2, CAS 1071-93-8). Sourcing neat Carbohydrazide Powder allows water-treatment formulators, power plants, and polymer manufacturers to prepare exact solution concentrations on-site without paying freight on 88% to 95% water.

Common Product and Chemical Names:
Carbohydrazide Powder
Carbohydrazide
Carbonic Dihydrazide
Carbonohydrazide
1,3-Diaminourea
N,N'-Diaminourea
sym-Diaminourea
Carbodihydrazide
Hydrazine Carbohydrazide / Carbonic Acid Dihydrazide
4-Aminosemicarbazide
Cabazide
CHZ / CHZ Powder
Karbohidrazid Toz
Karbohidrazit
Karbonik Dihidrazid

CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION

Product name: Carbohydrazide Powder
Systematic IUPAC Name: Carbonic dihydrazide (also Carbonohydrazide)
Alternative chemical names: 1,3-Diaminourea, Carbodihydrazide, 4-Aminosemicarbazide, N,N'-Diaminourea, Cabazide, CHZ
Turkish names: Karbohidrazid Toz, Karbohidrazit, Karbonik Dihidrazid, 1,3-Diaminoüre
CAS Registry Number: 497-18-7
EC / EINECS Number: 207-837-2
PubChem CID: 10337
Molecular Formula: CH6N4O
Condensed Structural Formula: OC(NHNH2)2 or H2N-NH-C(=O)-NH-NH2
Molecular Weight: 90.085 g/mol (commonly rounded to 90.08 g/mol)
Elemental Composition (Theoretical): Carbon 13.33 wt%, Hydrogen 6.71 wt%, Nitrogen 62.19 wt%, Oxygen 17.76 wt%
Chemical Class: Symmetrical carbonic acid dihydrazide / Hydrazine derivative / Urea derivative
Physical Form: White to off-white free-flowing crystalline powder or fine needle-like crystals
Ionic / Acid-Base Character: Weakly basic amphoter in aqueous solution (1%–10% aqueous solution pH ~7.2 to 9.5; forms mono- and di-acid salts such as carbohydrazide hydrochloride or sulfate with mineral acids)
Standard Commercial Assay: >= 98.0% min. or >= 99.0% min. Carbohydrazide (dry basis)
Typical Residual Free Hydrazine Limit: <= 50 ppm to <= 200 ppm (ultra-low free hydrazine grade <= 50–100 ppm; standard technical grade <= 200–500 ppm)
Primary Technical Functions: All-volatile dissolved oxygen scavenger for boiler feedwater and closed loops, ferrous and cuprous metal oxide passivator, ambient-temperature keto-hydrazide crosslinker for waterborne polymers, latent curing agent for epoxy resins, aldehyde/ketone scavenger and color stabilizer, and C1 heterocyclic synthesis intermediate
CAS No. 497-18-7 and EC No. 207-837-2 uniquely identify anhydrous Carbohydrazide across all industrial, water-treatment, polymer-crosslinking, and fine-chemical synthesis grades.
During procurement and safety documentation review, CAS No. 497-18-7 (Carbohydrazide Powder) must be clearly differentiated from free Hydrazine (CAS 302-01-2, EC 206-114-9), Hydrazine Hydrate (CAS 7803-57-8), Semicarbazide (NH2-C(=O)-NH-NH2, CAS 57-56-7, the mono-hydrazide of carbonic acid), Thiosemicarbazide (CAS 79-19-6), Thiocarbohydrazide (SC(NHNH2)2, CAS 2231-57-4, the sulfur analog), and Adipic Dihydrazide (CAS 1071-93-8).

CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF CARBOHYDRAZIDE POWDER

Carbohydrazide (H2N-NH-C(=O)-NH-NH2) features a planar, resonance-stabilized central ureido-like carbonyl core bonded symmetrically to two terminal primary amino (-NH2) groups via nitrogen-nitrogen single bonds. In the solid state, X-ray crystallography shows that Carbohydrazide molecules pack into a dense hydrogen-bonded network (crystal density ~1.616 g/cm3) in which the carbonyl oxygen accepts multiple intermolecular N-H···O=C hydrogen bonds from neighboring amide (-NH-) and terminal amino (-NH2) protons.
This extensive intermolecular hydrogen bonding explains two critical physical properties of Carbohydrazide Powder: first, despite a low molecular weight of 90.085 g/mol, it is a non-volatile crystalline solid with a high melting point of 152 to 154 degrees Celsius and a negligible vapor pressure at 25 degrees Celsius (< 0.0001 Pa); second, it dissolves readily in polar protic water (~320 g/L at 20–25 °C) via strong hydration of its four nitrogen atoms and one carbonyl oxygen, while remaining virtually insoluble in non-polar and low-polarity organic solvents such as diethyl ether, benzene, chloroform, and anhydrous ethanol.

Dissolution of Carbohydrazide Powder in ambient water is noticeably endothermic (absorbing heat of solution as the crystal lattice hydrogen bonds break), which is an important practical consideration when dissolving bags of powder into unheated plant make-up tanks.
Electronically, the two terminal -NH2 nitrogen atoms exhibit the alpha-effect: the adjacent amide nitrogen atom (-NH-) possesses a lone pair of electrons that raises the highest occupied molecular orbital (HOMO) energy of the terminal amino group, making the terminal -NH2 groups of Carbohydrazide exceptionally strong nucleophiles toward electrophilic carbonyl carbons (aldehydes, ketones, esters, and epoxides) and active reducing agents toward dissolved molecular oxygen (O2) and high-valence metal oxides (Fe3+, Cu2+).

At the same time, conjugation of the internal -NH- lone pairs with the central electron-withdrawing carbonyl group (C=O) moderates the volatility and spontaneous auto-oxidation sensitivity of the hydrazinyl moieties compared to free hydrazine (N2H4). As a result, dry Carbohydrazide Powder is stable in sealed containers at ambient warehouse temperatures, yet reacts rapidly in solution once exposed to dissolved oxygen, oxidizers, or reactive carbonyls.
From a redox perspective, each mole of Carbohydrazide (90.085 g/mol) donates 4 moles of electrons when oxidized completely to nitrogen gas, carbon dioxide, and water: CH6N4O + 2 O2 -> 2 N2 + CO2 + 3 H2O. This 4-electron stoichiometry gives Carbohydrazide an oxygen-scavenging equivalent weight of 22.52 g per mole of electrons, or a theoretical mass ratio of 1.408 mg of Carbohydrazide per 1.0 mg of dissolved O2.
Furthermore, Carbohydrazide acts as a versatile multidentate chelating ligand toward transition metal ions (such as Cu2+, Ni2+, Co2+, Zn2+, Fe2+, Mn2+, and Cd2+), coordinating predominantly through the carbonyl oxygen atom and one or both terminal amino nitrogen atoms to form stable five-membered chelate rings.

PRODUCTION AND CHEMICAL ORIGIN OF CARBOHYDRAZIDE POWDER

Commercial Carbohydrazide Powder is manufactured synthetically via the nucleophilic hydrazinolysis of carbonic acid derivatives with hydrazine hydrate (N2H4·H2O). Modern industrial production relies primarily on the dialkyl carbonate route—specifically the dimethyl carbonate (DMC) or diethyl carbonate (DEC) process—which has largely displaced older phosgene, urea, or carbonate ester routes due to superior product purity, higher yield, and ultra-low residual free hydrazine.
The standard industrial manufacturing process via the Dimethyl Carbonate (DMC) / Diethyl Carbonate (DEC) route proceeds through four controlled unit operations:

- 1. Nucleophilic Hydrazinolysis (Condensation): Purified dimethyl carbonate (CH3O-C(=O)-OCH3) or diethyl carbonate ((C2H5O)2CO) is reacted with a stoichiometric charge of aqueous hydrazine hydrate (typically 80% N2H4·H2O) in a jacketed stainless steel or glass-lined reactor at 50 to 95 degrees Celsius under an inert nitrogen blanket. The reaction proceeds in two sequential steps: first forming methyl or ethyl carbazate (RO-C(=O)-NH-NH2) as an intermediate, and then condensing with a second equivalent of hydrazine at 75 to 105 degrees Celsius to yield Carbohydrazide (H2N-NH-C(=O)-NH-NH2) and two equivalents of methanol or ethanol.

- 2. Alcohol Distillation and Concentration: Once reaction conversion exceeds 98%–99%, methanol (boiling point 64.7 °C) or ethanol (boiling point 78.4 °C) and excess water are distilled off overhead under reduced pressure at controlled temperatures (strictly kept below 105–110 °C to prevent thermal self-condensation of Carbohydrazide into 4-amino-1,2,4-triazolidin-3,5-dione / urazole).

- 3. Controlled Cooling Crystallization and Centrifugation: The concentrated aqueous Carbohydrazide liquor is cooled gradually to 5 to 15 degrees Celsius in a crystallizer, precipitating dense white prismatic crystals of Carbohydrazide while keeping trace unreacted hydrazine and soluble by-products in the mother liquor. The crystal slurry is separated by centrifugation and washed with chilled deionized water or aqueous alcohol.

- 4. Vacuum Drying to Ultra-Low Free Hydrazine Powder: The wet cake is dried under vacuum at 55 to 80 degrees Celsius. Vacuum drying strips away both surface moisture (to <= 0.2%–0.5%) and trace volatile free hydrazine (down to <= 50–200 ppm), yielding free-flowing white Carbohydrazide Powder.
An alternative industrial pathway reacts urea (CO(NH2)2) with hydrazine hydrate at 100 to 140 degrees Celsius under pressure while continuously stripping evolved ammonia gas (CO(NH2)2 + 2 N2H4 -> OC(NHNH2)2 + 2 NH3). However, because the higher reaction temperature of the urea route can generate trace cyclic urazole or biurea impurities unless recrystallized carefully, the dimethyl/diethyl carbonate route is preferred for high-purity (>= 99.0%) and polymer-crosslinking grades.

Ataman Kimya operates as an international chemical supplier and distributor providing commercial grades of Carbohydrazide Powder from established chemical producers; buyers requiring specific limits on residual free hydrazine (such as <= 50 ppm or <= 100 ppm) or particle-size / bulk-density specifications should state these criteria during inquiry.

PHYSICAL AND CHEMICAL PROPERTIES OF CARBOHYDRAZIDE POWDER

Carbohydrazide Powder is characterized by well-defined crystallographic, thermal, and wet-chemical properties that govern its safe storage, aqueous dissolution, and stoichiometric dosing.
General technical properties and standard commercial specification ranges:
Physical appearance (at 20–25 °C): White to off-white free-flowing crystalline powder or fine needle-like crystals
Odor: Odorless (or virtually odorless)
CAS Registry Number: 497-18-7
EC / EINECS Number: 207-837-2
Chemical formula: CH6N4O (H2N-NH-C(=O)-NH-NH2)
Molecular weight: 90.085 g/mol
Nitrogen content (theoretical): 62.19% w/w
Active Assay (Purity, dry basis, iodometric/bromometric titration or HPLC): >= 98.0% min. or >= 99.0% min. (typical batch result: 99.1% to 99.8%)
Melting point / Thermal decomposition range: 152.0 to 154.5 degrees Celsius (melts with vigorous exothermic decomposition releasing N2, NH3, CO, CO2, and H2O; onset of slow thermal degradation above 120–130 °C)
Boiling point: Not applicable (decomposes at melting point around 153–154 °C before boiling)
True crystal density (at 20 °C): Approximately 1.616 g/cm3 (literature range: 1.31 to 1.62 g/cm3 depending on measurement method)
Bulk / Apparent density (untapped powder): Typically 0.55 to 0.80 g/cm3
Vapor pressure (at 25 °C): Negligible (< 0.0001 Pa; non-volatile solid)
Flash point: Not applicable (incombustible / non-flammable solid under standard flash-point tests, though dry powder decomposes exothermically if heated above 150 °C)
Water solubility (at 20–25 °C): Freely soluble, approximately 300 to 330 g/L (~32 g/100 mL water; solubility increases sharply with temperature; dissolution in water is endothermic)
Organic solvent solubility: Practically insoluble in anhydrous ethanol, diethyl ether, benzene, toluene, and chloroform; sparingly soluble in hot methanol or dimethyl sulfoxide (DMSO)
pH of aqueous solution (at 20–25 °C): Typically 7.2 to 9.5 (for a 1% to 10% w/w aqueous solution; commonly 7.5 to 8.8 at 5% w/w)
Octanol-water partition coefficient (log Kow): Approximately -2.70 (strongly hydrophilic; does not bioaccumulate)
Free Hydrazine (N2H4) impurity content: Typically <= 50 ppm to <= 200 ppm in low-hydrazine grades (<= 500 ppm max in standard industrial grades)
Moisture / Loss on Drying (at 60–70 °C under vacuum): Typically <= 0.20% to <= 0.50% w/w
Ash / Residue on Ignition (Sulfated Ash): Typically <= 0.05% to <= 0.10% w/w
Chloride (Cl-) and Sulfate (SO4 2-) content (for high-pressure boiler grades): Typically <= 10 to <= 50 ppm
Heavy metals (as Pb) and Iron (Fe): Typically <= 10 ppm (Fe <= 5–10 ppm)
Color of 10% w/w aqueous solution (APHA / Hazen Pt-Co): Typically <= 10 to <= 20 APHA (clear and colorless)
Water-insoluble matter: <= 0.02% to <= 0.05% w/w
Oxygen-scavenging stoichiometry (direct reaction): 1.41 mg Carbohydrazide per 1.0 mg dissolved O2 (practical plant feed rate: 1.5 to 3.0 ppm Carbohydrazide per 1.0 ppm O2 plus residual)
Keto-hydrazide crosslinking equivalent weight: 45.04 g/mol of reactive -NHNH2 group (or 22.52 g/mol of active N-H hydrogen in epoxy curing)
These values are provided for general technical orientation and must not be assumed to apply identically to every commercial supplier or grade. Exact guaranteed limits must be confirmed on the product TDS and batch COA.

WHY EACH IMPORTANT PROPERTY OF CARBOHYDRAZIDE POWDER MATTERS IN PRACTICE

Water-treatment engineers, power-plant chemists, polymer formulators, and fine-chemical synthesis teams monitor specific analytical parameters on a Carbohydrazide Powder COA because each parameter directly impacts workplace safety, boiler metallurgy, or polymerization stoichiometry:

- Active Carbohydrazide Assay (>= 98.0% or >= 99.0%): Governs the exact redox electron capacity in boiler oxygen scavenging and the exact molar hydrazide (-NHNH2) stoichiometry when crosslinking diacetone acrylamide (DAAM) waterborne polymers or synthesizing heterocycles. In keto-hydrazide latex crosslinking, even a 3% deficit in active dihydrazide leaves unreacted ketone groups that reduce film solvent and block resistance.

- Residual Free Hydrazine Content (N2H4, ppm): This is the single most critical safety and regulatory parameter on a Carbohydrazide Powder COA. Because hydrazine is classified under GHS/CLP as a Category 1B carcinogen with strict occupational exposure limits and EU REACH SVHC status (when >= 0.1% / 1,000 ppm), keeping residual free hydrazine in Carbohydrazide Powder below 200 ppm—and ideally <= 50 to 100 ppm—ensures that the solid powder and its diluted 5%–10% aqueous solutions remain below regulatory SVHC/carcinogen mixture classification thresholds and protect operators from hydrazine vapor inhalation during make-up.

- Melting Point and Narrow Melting Range (152.0 to 154.5 °C): A sharp melting/decomposition onset between 152 and 154 degrees Celsius confirms high crystallographic purity and freedom from urea, semicarbazide, or cyclic urazole (4-amino-1,2,4-triazolidin-3,5-dione, MP >300 °C) by-products. A depressed or broad melting range (< 149 °C) signals moisture or low-melting carbazate impurities.

- Ash / Residue on Ignition (<= 0.05%–0.10%) and Trace Halides (Cl-, SO4 2-): In high-pressure utility boilers (>60–100 bar) and attemperator/desuperheater spray water, the entire purpose of selecting Carbohydrazide over sodium sulfite is to maintain zero dissolved solids. Low ash and negligible chloride/sulfate content ensure that dosing Carbohydrazide does not introduce corrosive chloride stress-cracking ions or turbine blade deposits.

- Aqueous Solution Clarity and Insolubles (<= 0.02%–0.05%, APHA <= 10–20): When Carbohydrazide Powder is dissolved at 5% to 12% w/w in deionized water for chemical metering pumps or added to clear waterborne polyurethane/acrylic coatings, any insoluble cyclic condensation by-products (such as urazole) cause filter plugging, metering-pump check-valve fouling, or coating haze.

- Moisture / Loss on Drying (<= 0.20%–0.50%): Keeps the crystalline powder free-flowing in bags and hoppers, prevents hard caking during warehouse storage, and avoids slow hydrolytic generation of trace hydrazine during warm storage.

- Aqueous pH (7.2 to 9.5 at 1%–10% w/w): Confirms freedom from acidic mineral salts or excess ammonia/hydrazine, ensuring compatibility with alkaline boiler feedwater (pH 8.5–10.0) and ammonia-neutralized anionic acrylic/PUD dispersions (pH 7.5–9.0).

HOW DOES CARBOHYDRAZIDE POWDER WORK AT THE MOLECULAR LEVEL?

Carbohydrazide Powder operates through four distinct, well-characterized molecular pathways depending on the chemical environment:
- 1. Dual-Regime Dissolved Oxygen Scavenging (Direct Low-Temperature Oxidation + High-Temperature Hydrolysis): In boiler feedwater, deaerator storage tanks, condensate lines, and closed cooling loops, Carbohydrazide scavenges dissolved oxygen (O2) across two temperature regimes. At low to moderate temperatures (20 to 135 °C)—before any thermal hydrolysis occurs—the intact Carbohydrazide molecule reacts directly with dissolved oxygen via a 4-electron transfer pathway: H2N-NH-C(=O)-NH-NH2 + 2 O2 -> 2 N2 + CO2 + 3 H2O. Because of the alpha-effect of its two hydrazide groups, intact Carbohydrazide reacts with dissolved oxygen faster at temperatures below 100 °C than uncatalyzed hydrazine! When trace redox catalysts such as hydroquinone (0.05%–0.2% relative to Carbohydrazide) or trace Cu2+/Fe2+/Co2+ ions are present, the quinone/hydroquinone redox shuttle accelerates electron transfer from Carbohydrazide to O2 even in ambient or warm water (25–80 °C). At higher boiler temperatures above 135 to 180 °C, residual Carbohydrazide undergoes quantitative hydrothermal hydrolysis into two moles of in-situ hydrazine and one mole of carbon dioxide: H2N-NH-C(=O)-NH-NH2 + H2O -> 2 N2H4 + CO2, and the liberated hydrazine scavenges remaining oxygen (N2H4 + O2 -> N2 + 2 H2O). At very high temperatures (>200–270 °C), excess hydrazine decomposes into ammonia and nitrogen (3 N2H4 -> 4 NH3 + N2), which alcalinizes steam condensate and protects return lines against carbonic acid corrosion.

- 2. Reductive Metal Oxide Passivation (Hematite-to-Magnetite and Cupric-to-Cuprous Conversion): Dissolved oxygen in boiler water oxidizes carbon steel surfaces into porous, non-adherent red rust (ferric oxide / hematite, Fe2O3 or FeOOH), which spalls off and creates differential-aeration pitting cells. Carbohydrazide reduces Fe(III) oxide directly into a dense, cubic spinel layer of black magnetite (Fe3O4) that adheres tightly to the underlying steel and blocks further ion diffusion: 6 Fe2O3 + CH6N4O -> 4 Fe3O4 + 2 N2 + CO2 + 3 H2O. On copper and admiralty brass heat-exchanger and condenser tubes, Carbohydrazide reduces loose cupric oxide (CuO) into a compact, protective cuprous oxide (Cu2O) film: 4 CuO + CH6N4O -> 2 Cu2O + 2 N2 + CO2 + 3 H2O.

- 3. Ambient-Temperature Keto-Hydrazide Dehydration Crosslinking in Waterborne Polymers: In one-component (1K) self-crosslinking waterborne acrylic emulsions and polyurethane dispersions (PUDs) containing copolymerized ketone monomers—most commonly diacetone acrylamide (DAAM) or acetoacetoxyethyl methacrylate (AAEM)—Carbohydrazide is dissolved in the aqueous phase at pH 7.5 to 9.0. Inside the wet paint can, excess water and alkaline pH keep the condensation equilibrium shifted toward the uncrosslinked reactants, giving 6 to 12+ months of pot-life stability. Once the coating is applied to wood, metal, plastic, or leather and water + neutralizing amine evaporate, the local pH drops and the two nucleophilic -NHNH2 groups of Carbohydrazide attack the pendant ketone carbonyls (-C(=O)CH3) on adjacent polymer chains, splitting out water to form covalent dihydrazone crosslinks: 2 Polymer-C(=O)CH3 + H2N-NH-C(=O)-NH-NH2 -> Polymer-C(CH3)=N-NH-C(=O)-NH-N=C(CH3)-Polymer + 2 H2O. Because Carbohydrazide has a molecular weight of only 90.085 g/mol (equivalent weight 45.04 g/eq, nearly half that of adipic dihydrazide at 87.10 g/eq), it creates a tighter, more rigid inter-chain crosslink bridge with half the mass addition.

- 4. Nucleophilic Epoxy Ring-Opening and Bifunctional Cyclocondensation: In one-component heat-cured epoxy adhesives and powder coatings, the four active N-H bonds of Carbohydrazide remain insoluble and latent at room temperature, then ring-open oxirane groups above 110–140 °C to form a densely crosslinked beta-hydroxy-hydrazide polymer network. In organic synthesis, the 1,3-diaminourea skeleton undergoes regioselective cyclocondensation with carboxylic acids, orthoesters, beta-diketones, CS2, or phosgene equivalents to build 1,2,4-triazole, 1,3,4-oxadiazole, and 1,2,4-triazinone rings.

WHAT PROBLEMS CAN CARBOHYDRAZIDE POWDER HELP SOLVE?

Power plant engineers, water treatment specialists, and polymer chemists select Carbohydrazide Powder to solve seven critical operational, safety, and formulation challenges.

Severe carcinogen exposure, volatility, and flammability risks of liquid Hydrazine
Liquid hydrazine hydrate is a volatile, fuming liquid classified as a Category 1B carcinogen, skin sensitizer, and acute inhalation toxin, requiring sealed transfer systems, respirators, and strict regulatory reporting. Replacing liquid hydrazine with non-volatile, non-flammable Carbohydrazide Powder eliminates ambient hydrazine vapor emissions during storage and handling while preserving identical high-temperature boiler chemistry.

High dissolved solids, conductivity spikes, and blowdown heat losses from Sodium Sulfite
Conventional inorganic oxygen scavengers such as catalyzed sodium sulfite (Na2SO3) or sodium bisulfite (NaHSO3) oxidize into non-volatile sodium sulfate (Na2SO4), increasing boiler water total dissolved solids (TDS) and electrical conductivity. This forces higher boiler blowdown rates (wasting fuel and treated water) and prohibits sulfite use in high-pressure boilers (>40–60 bar) or attemperator spray water where solids deposit on superheater tubes and steam turbine blades. Furthermore, above 180–200 °C, sulfite decomposes into corrosive sulfur dioxide (SO2) and hydrogen sulfide (H2S). Carbohydrazide 
Powder reacts with oxygen to form only volatile N2, CO2, and H2O, adding zero dissolved solids and zero sulfur species.

Sluggish low-temperature oxygen scavenging during boiler startups, wet layups, and in closed loops
Uncatalyzed hydrazine reacts extremely slowly with dissolved oxygen at water temperatures below 100 to 150 degrees Celsius, leaving feedwater heaters, economizers, and idle boilers during wet layup vulnerable to oxygen pitting. Carbohydrazide reacts directly with dissolved oxygen at lower temperatures (20 to 100 °C)—especially when catalyzed with trace hydroquinone—protecting pre-boiler equipment and closed chilled/hot water loops.

Exorbitant freight and drum-handling costs of shipping 5% to 12% liquid Carbohydrazide solutions
Commercial liquid oxygen-scavenger products typically contain only 5% to 12% w/w Carbohydrazide dissolved in 88% to 95% water. For regional water-treatment formulators and export buyers, importing neat Carbohydrazide Powder (>= 98%–99% active) and dissolving it locally in deionized water cuts international shipping weight and packaging volume by 85% to 95%.

Exfoliation of porous red iron oxide (Fe2O3) and copper corrosion in steam-condensate cycles
Oxygen ingress during load swings creates porous hematite rust and cupric oxide scale that sloughs off and deposits on high-heat-flux boiler tubes, causing under-deposit corrosion and tube failure. Carbohydrazide converts porous Fe2O3 into dense, protective magnetite (Fe3O4) and CuO into Cu2O.

Two-component pot-life limitations and toxicity of isocyanate/aziridine crosslinkers in waterborne coatings
Two-component (2K) waterborne coatings crosslinked with polyisocyanates or polyaziridines suffer from short pot-life (2–6 hours), waste of mixed paint, and respiratory sensitization or mutagenicity hazards. Formulating one-component (1K) DAAM-modified acrylic or polyurethane dispersions with Carbohydrazide Powder provides >6–12 months of single-pack storage stability combined with rapid ambient-temperature hydrazone curing upon drying.

Aldehyde/ketone rancidity, yellowing, and free-radical degradation in soaps and synthetic fibers
Trace aldehydes, ketones, and peroxides formed during air exposure cause yellowing, rancid odors, and molecular weight degradation in soaps, detergents, and synthetic spandex/polyamide fibers. Carbohydrazide Powder traps trace carbonyls as stable hydrazones and quenches oxidizing radicals.

BENEFITS FOR THE MANUFACTURER AND END USER

Incorporating Carbohydrazide Powder delivers substantial economic, safety, and technical advantages for chemical formulators, plant operators, and end users.
Benefits for the Water-Treatment Formulator, Coating Manufacturer, and Synthesis Chemist:
- Concentrated 98%–99%+ Solid Active Form: Eliminates shipping 88%–95% water across borders; one 25 kg bag or fiber drum of Carbohydrazide Powder manufactures 200 kg to 500 kg of finished 5%–12% liquid boiler oxygen scavenger.
- Non-Volatile, Non-Flammable Workplace Handling: Zero vapor pressure at 25 °C eliminates fuming liquid hydrazine transfer hazards in blending plants.
- Ultra-Low Equivalent Weight in Polymer Crosslinking (45.04 g/eq): Requires almost 50% less weight than adipic dihydrazide (ADH, 87.10 g/eq) to crosslink an equivalent number of ketone groups in waterborne acrylics and PUDs, while yielding higher water solubility (~320 g/L vs. ~80–120 g/L for ADH) and higher film hardness/Tg.
- Clean, Quantitative Heterocyclic Cyclization: Symmetrical 1,3-diaminourea structure provides high yields and simple purification in 1,2,4-triazole and triazinone API/agrochemical manufacturing.
Benefits for the Power Plant, Industrial Facility, and Final Product:
- Zero Total Dissolved Solids (Zero-TDS) Boiler Operation: Produces only N2, CO2, and H2O upon oxygen scavenging, allowing lower boiler blowdown rates, higher cycles of concentration, fuel/water savings, and safe use in high-pressure utility boilers and attemperator spray water.
- Dual Oxygen Scavenging + Magnetite Passivation: Simultaneously removes dissolved O2 down to < 5–10 ppb and builds a self-healing black Fe3O4 / Cu2O protective oxide film across boiler tubes, economizers, and condensers.
- Effective Across Wide Temperature Windows (20 °C to >250 °C): Protects cold wet-layup boilers, warm deaerators/economizers, and high-pressure steam drums alike.
- Durable, Chemical-Resistant 1K Waterborne Coatings: Wood, metal, and concrete coatings cured via DAAM-Carbohydrazide crosslinking achieve 2K-level methyl ethyl ketone (MEK) double-rub resistance, water resistance, and block resistance from a single-pack container.

APPLICATIONS OF CARBOHYDRAZIDE POWDER

Carbohydrazide Powder is deployed across industrial water treatment, polymer science, fine chemical synthesis, and specialty stabilization.

Boiler feedwater oxygen scavenging and steam-cycle metal passivation
The primary global industrial application of Carbohydrazide Powder is the formulation of all-volatile oxygen scavengers and metal passivators for medium- and high-pressure industrial and utility steam boilers (including power generation stations, petrochemical refineries, pulp and paper mills, chemical plants, and marine boilers). Dosed continuously as an aqueous solution into the deaerator storage tank drop-leg or boiler feedwater pump suction, Carbohydrazide strips residual dissolved oxygen from ~7–50 ppb down to < 5 ppb while passivating carbon steel feedwater heaters, economizers, and boiler tubes with a dense magnetite (Fe3O4) layer and protecting copper-alloy condensers.

Boiler wet layup, offline preservation, and post-acid-cleaning passivation
During scheduled boiler turnarounds, seasonal shutdowns, or standby wet layup, higher concentrations of Carbohydrazide (typically 100 to 400 ppm active in alkaline demineralized water at pH 9.5–10.5) are circulated through the offline boiler and superheater to prevent ambient oxygen ingress corrosion without introducing inorganic salts that would require flushing before restart. Similarly, following chemical acid cleaning (citric, hydrochloric, or EDTA descaling) of boiler tubes, Carbohydrazide solutions are heated in the boiler to rapidly passivate the bare, active steel surface with a uniform black magnetite film.

Closed-loop cooling, chilled-water, and district-heating corrosion inhibition
In closed recirculating cooling water systems, chilled-water loops, hot-water district heating networks, and hydrostatic test waters where dissolved oxygen causes severe pitting of mild steel and copper components, catalyzed Carbohydrazide formulations scavenge dissolved oxygen introduced during make-up or pump seal leakage and maintain passive oxide surfaces without contributing scaling salts.

Ambient-temperature keto-hydrazide crosslinker for waterborne acrylics and polyurethanes (PUDs)
In coatings, adhesives, leather finishes, and textile binders, Carbohydrazide Powder is used as a high-efficiency ambient-temperature crosslinker for ketone-functionalized waterborne polymers (specifically acrylic, styrene-acrylic, vinyl-acrylic, and polyurethane dispersions copolymerized with 2% to 8% diacetone acrylamide, DAAM). Upon film drying and water evaporation, Carbohydrazide reacts with the polymer ketone groups to form a tightly crosslinked hydrazone network, dramatically improving water resistance, solvent/stain resistance, hardness, and anti-blocking performance in 1K wood lacquers, industrial metal primers, concrete sealers, and PSA/laminating adhesives.

Latent thermal curing agent for one-component (1K) epoxy resins and powder coatings
Because Carbohydrazide Powder has a sharp melting point of 152–154 °C and is insoluble in liquid bisphenol-A/F epoxy resins at ambient temperature, finely micronized Carbohydrazide acts as a latent thermal hardener (similar to dicyandiamide, DICY, but curing at lower temperatures of 110–145 °C, especially with substituted urea accelerators) in 1K structural epoxy adhesives, electronic encapsulating compounds, prepregs, and thermosetting epoxy powder coatings.

Pharmaceutical and agrochemical heterocyclic intermediate
In organic and medicinal chemistry, Carbohydrazide Powder serves as a versatile C1 hydrazide synthon for constructing nitrogen-rich five- and six-membered heterocycles—including 1,2,4-triazoles, 4-amino-1,2,4-triazolin-5-ones, 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, and 1,2,4-triazin-5-ones. It is used to manufacture triazinone herbicides (such as metamitron and metribuzin intermediates), triazole fungicides, cephalosporin and beta-lactam antibiotic side chains, antitubercular and antibacterial semicarbazone/hydrazone derivatives, and enzyme inhibitors.

Energetic materials, propellants, and automotive airbag gas generants
Because Carbohydrazide contains 62.19% nitrogen by weight, coordinates strongly with metal cations, and oxidizes exclusively into low-molecular-weight gases (N2, CO2, H2O), Carbohydrazide Powder is used as a ligand to synthesize energetic transition-metal coordination complexes (such as metal carbohydrazide nitrates and perchlorates used as lead-free primary explosives and detonator charges), as a nitrogen-rich fuel component in non-azide automotive airbag gas generants, and as a burning-rate modifier and stabilizer in solid rocket propellants.

Aldehyde scavenger and color/oxidation stabilizer in soaps, synthetic fibers, and photography
In soap and detergent manufacturing, synthetic rubber/elastomers, and polyurethane/polyamide chemical fibers (spandex and nylon), trace additions of Carbohydrazide Powder scavenge trace formaldehyde, acetaldehyde, and lipid peroxidation aldehydes, preventing yellowing, odor development, and UV/thermal fiber embrittlement. In photographic processing, it acts as a fog-inhibiting stabilizer and aldehyde hardener scavenger in color developer baths.

WHICH INDUSTRIES USE CARBOHYDRAZIDE POWDER?

Carbohydrazide Powder is utilized across power generation, industrial water treatment, polymer formulation, and fine chemical manufacturing:
- Industrial and Utility Power Generation (coal, natural gas combined-cycle HRSGs, biomass, waste-to-energy, and cogeneration high-pressure steam plants)
- Water Treatment Chemical Blending and Service Companies (formulating liquid 5%–12% catalyzed and uncatalyzed boiler oxygen scavengers and closed-loop inhibitors)
- Petrochemical Refineries, Chemical Complexes, and Fertilizer Plants (high-pressure process steam generators, waste-heat boilers, and condensate return networks)
- Pulp and Paper, Sugar Refining, Textile, and Food Processing Plants (industrial steam boilers and turbine cogeneration loops where non-hydrazine volatile scavengers are preferred)
- Paints, Coatings, Wood Finishes, and Construction Chemicals (1K self-crosslinking DAAM waterborne acrylics, PUDs, concrete sealers, and epoxy powder coatings)
- Adhesives, Sealants, Leather Finishing, and Textile Binders (1K heat-cured epoxy structural adhesives and waterborne polyurethane/acrylic dispersions)
- Pharmaceutical API and Fine Chemical Synthesis (cephalosporin intermediates, 1,2,4-triazole and 1,3,4-oxadiazole heterocyclic building blocks)
- Agrochemical Manufacturing (triazinone herbicides, triazole fungicides, and plant growth regulators)
- Energetic Materials, Defense, Pyrotechnics, and Automotive Safety (airbag gas generants, propellant stabilizers, and lead-free energetic coordination complexes)
- Synthetic Fibers, Elastomers, Soaps, and Photographic Chemicals (spandex/polyamide anti-yellowing stabilizers, aldehyde scavengers, and developer additives)
Each industry emphasizes specific COA parameters: water-treatment blenders require high water solubility, zero insolubles, and low residual free hydrazine (<= 50–100 ppm); high-pressure utility plants require ultra-low chloride, sulfate, and ash limits; coating formulators require high active assay (>= 99.0%) and clear aqueous dissolution; and synthesis chemists require a sharp melting point (152–154 °C) and dry powder (< 0.2% moisture).

USE OF CARBOHYDRAZIDE POWDER IN BOILER WATER TREATMENT AND CORROSION INHIBITION

In industrial and utility steam generation, dissolved oxygen (O2) is the primary cause of waterside pitting corrosion in feedwater piping, stage heaters, economizers, and boiler drums. Even trace dissolved oxygen levels of 20 to 50 ppb exiting a mechanical thermal deaerator can cause deep, localized tuberculation and rapid tube perforation, while releasing iron and copper oxides that deposit on high-heat-flux waterwall tubes.
Carbohydrazide Powder is the industry-standard solid all-volatile oxygen scavenger used to eliminate residual dissolved oxygen after mechanical deaeration and passivate the entire steam-water circuit:

- Stoichiometric and Practical Dosing in Boiler Feedwater: Theoretically, 1.408 ppm (mg/L) of pure Carbohydrazide reacts completely with 1.0 ppm (mg/L) of dissolved oxygen (CH6N4O + 2 O2 -> 2 N2 + CO2 + 3 H2O). In practical boiler house operation, Carbohydrazide is dosed continuously into the storage section of the deaerator or the boiler feedwater pump suction at a rate of 1.5 to 3.0 ppm of Carbohydrazide per 1.0 ppm of dissolved oxygen, plus a small excess sufficient to maintain a measurable Carbohydrazide residual of 0.1 to 0.5 ppm (100 to 500 ppb, or 0.02 to 0.10 ppm expressed as equivalent N2H4) in the economizer inlet water.

- Optimal pH and Temperature Window: The oxygen-scavenging and metal-passivating reactions of Carbohydrazide proceed most rapidly in mildly alkaline feedwater at pH 8.5 to 10.0 (typically maintained with volatile neutralizing amines such as morpholine, cyclohexylamine, or monoethanolamine, or ammonia/caustic). While uncatalyzed Carbohydrazide reacts well from 80 to 250+ °C, adding 0.05% to 0.2% hydroquinone catalyst (relative to Carbohydrazide weight) accelerates oxygen removal in lower-temperature feedwater systems (30 to 90 °C) and closed cooling/heating loops.

- Mixed-Metallurgy Protection (Steel + Copper Alloys): In plants containing both carbon-steel boiler/economizer tubing and copper-nickel or admiralty brass surface condenser and low-pressure heater tubes, excessive free ammonia can cause oxygen-assisted stress-corrosion cracking or grooving of copper alloys. Because Carbohydrazide reacts directly with oxygen at moderate temperatures and generates less excess ammonia than high-dose hydrazine while reducing CuO to protective Cu2O, carefully controlled Carbohydrazide programs provide superior mixed-metallurgy protection.

- Analytical Monitoring in Boiler Water: Residual Carbohydrazide in feedwater is monitored spectrophotometrically at 455 nm using the para-dimethylaminobenzaldehyde (p-DMAB) reagent method (after acid hydrolysis to p-dimethylaminobenzalazine) or via direct redox/colorimetric test kits calibrated in ppb/ppm Carbohydrazide.

USE OF CARBOHYDRAZIDE POWDER IN POLYMER CROSSLINKING, COATINGS AND ADHESIVES

In modern low-VOC waterborne coatings, adhesives, and elastomers, the keto-hydrazide ambient-temperature self-crosslinking mechanism is one of the most widely adopted technologies for achieving two-component (2K) durability from a convenient one-component (1K) package.
Key technical roles and advantages of Carbohydrazide Powder in polymer systems include:

- High-Density Crosslinking of DAAM-Modified Acrylics and PUDs: When an acrylic emulsion or polyurethane dispersion is synthesized with 2% to 6% w/w diacetone acrylamide (DAAM, CAS 2873-97-4), post-adding an aqueous solution of Carbohydrazide Powder at a stoichiometric ratio of 0.80 to 1.00 mole of hydrazide (-NHNH2) group per mole of ketone (-C(=O)CH3) group (i.e., 0.40 to 0.50 mole of Carbohydrazide per mole of DAAM) creates a shelf-stable 1K dispersion. Because the molecular weight of Carbohydrazide (90.085 g/mol, equivalent weight 45.04 g/eq) is nearly half that of Adipic Dihydrazide (ADH, MW 174.20 g/mol, equivalent weight 87.10 g/eq), 1.00 g of DAAM (MW 169.22 g/mol) requires only ~0.24 to 0.27 g of Carbohydrazide compared to ~0.46 to 0.51 g of ADH!

- Higher Water Solubility and Faster Film Cure: Carbohydrazide dissolves in water at ~320 g/L at 20 °C (approximately 3 times more soluble than ADH at ~80–120 g/L), allowing formulators to prepare concentrated 15% to 25% aqueous crosslinker pre-solutions that blend effortlessly into high-solids latexes without crystallization or grit. Furthermore, the short, rigid C1 urea-like bridge (-NH-C(=O)-NH-) between the two hydrazone linkages raises glass transition temperature (Tg), Konig pendulum hardness, early block resistance, and chemical/solvent resistance compared to the flexible four-methylene (-CH2-)4 bridge of ADH.

- Latent Thermal Curing of 1K Epoxy Resins and Powder Coatings: Finely ground Carbohydrazide Powder (typically 3 to 15 phr based on epoxy resin weight) functions as a solid latent curing agent for bisphenol-A and novolac epoxy resins. Because its four active N-H protons ring-open epoxide groups above 115–145 °C, Carbohydrazide provides lower-temperature curing than dicyandiamide (DICY, which typically requires 160–180 °C without heavy acceleration) while maintaining multi-month ambient shelf life in 1K automotive structural adhesives, electronic potting compounds, and powder coatings.

- Formaldehyde Scavenging in Amino Resins and Wood Panels: In urea-formaldehyde (UF), melamine-formaldehyde (MF), and phenolic wood adhesives, paper wet-strength resins, and textile finishes, adding 0.5% to 3.0% Carbohydrazide Powder chemically traps free formaldehyde emitted during hot pressing or curing as non-volatile hydrazone/triazolidinone adducts, lowering indoor formaldehyde emissions to E0 / CARB Phase 2 / TSCA Title VI levels.

PHARMACEUTICAL, AGROCHEMICAL AND FINE CHEMICAL SYNTHESIS APPLICATIONS

In synthetic organic chemistry, Carbohydrazide Powder is a symmetric, highly nucleophilic C1 tetra-nitrogen building block used to construct bioactive heterocycles, energetic coordination compounds, and specialty functional additives:

- Synthesis of 1,2,4-Triazin-5-one Herbicides: In agrochemical manufacturing, Carbohydrazide reacts with alpha-keto acids or esters (such as phenylglyoxylic acid derivatives or trimethylpyruvic acid) followed by methylation to construct the 4-amino-1,2,4-triazin-5(4H)-one ring system, the core pharmacophore of major selective photosystem II-inhibiting herbicides used in sugar beet, potato, soybean, and tomato cultivation.

- Construction of 1,2,4-Triazole, 1,3,4-Oxadiazole, and Thiadiazole Rings: Condensing Carbohydrazide with carboxylic acids, acid chlorides, orthoesters, or carbon disulfide generates 4-amino-1,2,4-triazolidin-3,5-diones (urazoles), 1,3,4-oxadiazoles, and 1,2,4-triazole fungicides and pharmaceutical intermediates.

- Beta-Lactam Antibiotic and Hydrazone Prodrug Intermediates: In pharmaceutical synthesis, Carbohydrazide is used to introduce carbonyl-bishydrazide linkers and heterocyclic side chains into cephalosporin antibiotics, antimicrobial nitrofuran/quinolone derivatives, antitubercular agents, and pH-cleavable hydrazone drug-delivery conjugates.

- Energetic Coordination Complexes and Airbag Gas Generants: Reacting Carbohydrazide Powder in aqueous solution with transition metal nitrates or perchlorates (such as Ni(II), Co(II), Zn(II), Cu(II), or Mn(II)) precipitates crystalline tris(carbohydrazide)metal(II) complexes ([M(CHZ)3] or [M(CHZ)3]. These compounds serve as thermally stable, lead-free primary explosives, laser-ignitable detonators, and clean-burning nitrogen gas generants for automotive safety restraint (airbag) inflators.

FORMULATION AND PROCESS CONSIDERATIONS WHEN USING CARBOHYDRAZIDE POWDER

Process engineers, water-treatment formulators, and polymer chemists working with Carbohydrazide Powder should control six key operational parameters:
- 1. Compensation for Endothermic Cooling During Aqueous Dissolution: Dissolving Carbohydrazide Powder in water absorbs heat (endothermic enthalpy of solution), which can drop the temperature of a batch mixing tank by 5 to 12 degrees Celsius when preparing 10% to 15% w/w solutions. Because cooling slows down dissolution kinetics and lowers the saturation ceiling, use warm deionized water (25 to 40 °C, never exceeding 50 °C) and moderate mechanical agitation when dissolving bulk powder to achieve rapid, complete dissolution without undissolved bottom sediment.

- 2. Concentration Ceilings for Cold-Weather Liquid Concentrates: Although ~320 g/L (~24% w/w) of Carbohydrazide dissolves in water at 20–25 °C, solubility drops to ~120–150 g/L near 0 to 5 °C. Therefore, commercial liquid boiler-treatment concentrates intended for unheated winter transport or cold drum storage are typically formulated at 5.0% to 10.0% w/w (max 12.0% w/w) active Carbohydrazide in deionized water so that crystals never precipitate in metering pumps or suction lines during winter.

- 3. Strict Temperature Control Below 90–100 °C in Open vessels and Below 120 °C in Dry Processing: While Carbohydrazide is intended to hydrolyze into hydrazine inside closed, pressurized boilers above 135–180 °C, heating aqueous Carbohydrazide solutions above 70–90 °C in open atmospheric mixing tanks will slowly hydrolyze a fraction of the Carbohydrazide into volatile free hydrazine and CO2! Always prepare and store aqueous Carbohydrazide solutions below 40–45 °C. For dry powder compounding (e.g., epoxy curatives or energetic formulations), never expose dry Carbohydrazide Powder to temperatures above 115–120 °C during milling or drying, as exothermic decomposition begins near 152 °C.

- 4. pH Control in Keto-Hydrazide Waterborne Coating Formulations: When post-adding an aqueous Carbohydrazide solution into a DAAM-modified acrylic or polyurethane dispersion, ensure that the polymer dispersion is pre-neutralized with ammonia or a volatile tertiary amine (such as AMP-95 or triethylamine) to pH 7.8 to 9.0 before metering in the Carbohydrazide solution under agitation. If dispersion pH is acidic (< 6.5), premature keto-hydrazide condensation can occur inside the wet storage container, causing viscosity climb or gelation.

- 5. Deionized Water Quality and Hydroquinone Catalyst Stabilization: When formulating catalyzed liquid Carbohydrazide oxygen scavengers (containing 5%–10% Carbohydrazide and 0.05%–0.20% hydroquinone), always use oxygen-free or low-dissolved-oxygen deionized water with low trace iron/copper (< 0.5 ppm) and purge the container headspace with nitrogen. Trace dissolved oxygen and transition metals in raw tap water will slowly oxidize the hydroquinone catalyst into dark brown quinone polymers during drum storage.

- 6. Materials of Construction: Aqueous Carbohydrazide solutions (pH 7.5–9.5) and dry Carbohydrazide Powder are non-corrosive to austenitic stainless steel (AISI 304 and 316L), high-density polyethylene (HDPE), polypropylene (PP), PVC, glass, and PTFE/EPDM/FFKM seals. Avoid storing concentrated Carbohydrazide solutions in unlined copper, brass, bronze, or zinc/galvanized vessels, as Carbohydrazide chelates and slowly leaches copper and zinc ions, which catalyze premature solution decomposition.

TYPICAL USE LEVELS AND INITIAL FORMULATION APPROACHES FOR CARBOHYDRAZIDE POWDER

Typical incorporation and dosing levels for Carbohydrazide Powder depend on the target application and require verification under actual plant or formulation conditions:
- Liquid Boiler Oxygen Scavenger Concentrates: 5.0% to 12.0% w/w Carbohydrazide Powder dissolved in deionized water (optionally catalyzed with 0.05% to 0.25% w/w hydroquinone).
- Continuous Boiler Feedwater Dosing: 1.5 to 3.0 ppm active Carbohydrazide per 1.0 ppm dissolved O2 in deaerated feedwater, plus sufficient dose to maintain 0.1 to 0.5 ppm (100 to 500 ppb) Carbohydrazide residual at the economizer inlet.
- Boiler Wet Layup and Offline Passivation: 100 to 400 ppm active Carbohydrazide in demineralized water buffered to pH 9.5–10.5 with volatile amine or ammonia.
- Closed-Loop Cooling / Heating Water Treatment: 10 to 50 ppm active Carbohydrazide residual.
- 1K Self-Crosslinking Waterborne DAAM Acrylic / PUD Coatings: 0.4% to 2.5% w/w on total dispersion solids (stoichiometrically 0.40 to 0.50 mole of Carbohydrazide per 1.00 mole of copolymerized diacetone acrylamide, corresponding to ~0.24 to 0.27 g Carbohydrazide Powder per 1.00 g of DAAM monomer).
- 1K Latent Heat-Cured Epoxy Formulations: 3.0 to 12.0 phr (parts per hundred parts of liquid or solid epoxy resin, typically 0.85 to 1.05 active N-H equivalents per epoxide equivalent).
- Formaldehyde Scavenger / Soap & Fiber Stabilizer: 0.05% to 1.5% w/w based on resin, soap, or polymer weight.

COMPATIBILITY AND INCOMPATIBILITY OF CARBOHYDRAZIDE POWDER

Managing chemical and material compatibility is essential when storing, dissolving, and formulating Carbohydrazide Powder because it is a strong reducing agent and nucleophile:
- Compatibility with Boiler Water Treatment Additives: In alkaline boiler feedwater and drum water (pH 8.5–11.5), Carbohydrazide is fully compatible with volatile neutralizing amines (morpholine, cyclohexylamine, diethylaminoethanol, monoethanolamine), filming amines/polyamines, ammonia, sodium/potassium phosphates, caustic (NaOH/KOH), chelants (EDTA, NTA), and polymeric dispersants (polyacrylates, polymethacrylates, sulfonated copolymers).
- Compatibility with Waterborne Polymer Dispersions: Compatible with ammonia- or amine-neutralized anionic and nonionic acrylic, styrene-acrylic, vinyl-acetate/ethylene (VAE), and polyurethane dispersions (PUDs) at pH >= 7.5.
- Severe Incompatibility with Oxidizing Agents and Halogens: Carbohydrazide Powder and its solutions react vigorously and exothermically with strong oxidizers—including sodium/calcium hypochlorite (bleach), chlorine gas, bromine, hydrogen peroxide, peroxyacids, nitric acid, nitrates, nitrites, permanganates, chromates, chlorates, and perchlorates. In water treatment plants, never mix or co-inject Carbohydrazide into lines containing oxidizing biocides (chlorine, bromine, chlorine dioxide, or hydrogen peroxide), as they mutually destroy each other instantaneously with gas and heat evolution.
- Incompatibility with Strong Acids and Nitrosating Agents: Contact with concentrated mineral acids forms carbohydrazide salts or promotes hydrolysis to hydrazine salts; reaction with nitrous acid or nitrites (NO2-) at acidic pH can generate unstable, explosive carbonyl diazide (CO(N3)2). Never blend Carbohydrazide with sodium nitrite corrosion inhibitors under acidic or unbuffered conditions!
- Incompatibility with Aldehydes, Ketones, and Epoxides in Storage: Because Carbohydrazide condenses rapidly with aldehydes and ketones (acetone, MEK, formaldehyde, benzaldehyde) to form hydrazones, never contaminate Carbohydrazide Powder or its solutions with ketone/aldehyde solvents unless intentional crosslinking is desired.
- Incompatibility with Copper, Brass, and Heavy Metal Salts in Concentrated Storage: Neat copper, brass, bronze, and zinc surfaces slowly leach metal ions (Cu2+, Zn2+) into concentrated Carbohydrazide solutions, catalyzing premature decomposition and gas evolution. Use AISI 304 or 316L stainless steel, HDPE, polypropylene, PVC, glass, and PTFE, EPDM, or FFKM gaskets.

SIMILAR PRODUCTS AND ALTERNATIVES TO CARBOHYDRAZIDE POWDER

Selecting between Carbohydrazide Powder (CAS 497-18-7) and alternative oxygen scavengers or polymer crosslinkers requires comparing workplace toxicity, volatility, contribution to boiler dissolved solids, temperature kinetics, and equivalent weight.

CARBOHYDRAZIDE POWDER AND HYDRAZINE HYDRATE

Hydrazine Hydrate (N2H4·H2O, CAS No. 7803-57-8, active CAS 302-01-2, MW 50.06 g/mol for monohydrate, 32.05 g/mol for anhydrous N2H4) is the traditional all-volatile liquid oxygen scavenger (theoretical stoichiometry: 1.0 mg N2H4 per 1.0 mg O2).
While Hydrazine has a lower molecular weight than Carbohydrazide (requiring 1.0 ppm N2H4 vs. 1.41 ppm Carbohydrazide per ppm O2), liquid Hydrazine is a volatile, flammable, fuming liquid classified globally as a Category 1B carcinogen and REACH Substance of Very High Concern (SVHC). Carbohydrazide Powder (CAS 497-18-7) is a non-volatile, non-flammable crystalline solid that eliminates ambient hydrazine vapor exposure in storage and handling, reacts faster with dissolved oxygen than uncatalyzed hydrazine at temperatures below 100–135 °C, and hydrolyzes cleanly into hydrazine inside high-temperature boilers (>135–180 °C) to deliver identical zero-solids steam purity and magnetite passivation.

CARBOHYDRAZIDE POWDER AND SODIUM SULFITE / SODIUM BISULFITE

Sodium Sulfite (Na2SO3, CAS No. 7757-83-7, MW 126.04 g/mol) and Sodium Bisulfite (NaHSO3, CAS No. 7631-90-5) are low-cost inorganic oxygen scavengers widely used in low-pressure boilers (< 40 bar). However, scavenging 1.0 ppm of dissolved oxygen requires ~7.88 ppm of pure Na2SO3 (practical dose 8 to 10 ppm) and generates ~8.9 ppm of non-volatile Sodium Sulfate (Na2SO4) ash in the boiler drum!
By contrast, 1.41 ppm of Carbohydrazide Powder scavenges 1.0 ppm of O2 and leaves 0.0 ppm of dissolved solids in the boiler water. Moreover, above 180–200 °C (~60 bar), sodium sulfite thermally decomposes into corrosive SO2 and H2S gases that attack steam turbines and condensers, whereas Carbohydrazide operates safely from low-pressure loops up to supercritical utility boilers and attemperator spray water.

CARBOHYDRAZIDE POWDER AND DEHA (DIETHYLHYDROXYLAMINE)

N,N-Diethylhydroxylamine (DEHA, (C2H5)2NOH, CAS No. 3710-84-7, MW 89.14 g/mol) is a volatile liquid organic oxygen scavenger and metal passivator that distills overhead with steam to protect condensate lines. However, DEHA is a volatile liquid with a strong amine odor and a flash point around 45 °C, adds organic carbon (TOC / acetate/acetaldehyde breakdown products) to high-purity boiler water, and cannot be supplied as a dry powder.
Carbohydrazide Powder is an odorless, non-volatile solid raw material that introduces zero persistent organic acid breakdown products in high-pressure utility boilers (oxidizing completely to N2, CO2, and H2O) and can be shipped economically as a 99% dry powder.

CARBOHYDRAZIDE POWDER AND ERYTHORBIC ACID / SODIUM ERYTHORBATE

Erythorbic Acid (Isoascorbic Acid, C6H8O6, CAS No. 89-65-6, MW 176.12 g/mol) and Sodium Erythorbate (CAS No. 6381-77-7) are non-volatile, food-grade / FDA 21 CFR 173.310 compliant oxygen scavengers used when steam directly contacts food or culinary products. However, Erythorbic Acid has a much higher stoichiometric weight requirement (~5.5 ppm per 1.0 ppm O2), decomposes at high boiler temperatures into organic acids (glycolic, lactic, and acetic acids) that depress steam/condensate pH, and adds sodium ions if used as the sodium salt.
For power, refinery, petrochemical, paper, and non-food industrial boilers, Carbohydrazide Powder provides nearly 4 times higher oxygen-scavenging efficiency per kilogram with zero organic-acid pH depression.

CARBOHYDRAZIDE POWDER AND HYDROQUINONE

Hydroquinone (1,4-Benzenediol, C6H6O2, CAS No. 123-31-9, MW 110.11 g/mol) is an extremely fast ambient-temperature oxygen scavenger, but it is expensive as a bulk standalone scavenger and contributes aromatic organic carbon to boiler water at high doses.
In industrial practice, Hydroquinone and Carbohydrazide Powder are used synergistically rather than competitively: adding 0.05% to 0.25% Hydroquinone as a redox catalyst into a 5%–10% aqueous Carbohydrazide solution combines the instant ambient-temperature reaction speed of Hydroquinone with the high 4-electron capacity and clean N2/CO2 breakdown of Carbohydrazide.

CARBOHYDRAZIDE POWDER AND ADIPIC DIHYDRAZIDE (ADH) IN POLYMER CROSSLINKING

Adipic Dihydrazide (ADH, H2N-NH-C(=O)-(CH2)4-C(=O)-NH-NH2, CAS No. 1071-93-8, MW 174.20 g/mol, melting point ~177–184 °C) is the six-carbon aliphatic dihydrazide commonly used to crosslink DAAM-functional waterborne acrylics and PUDs.
Compared to ADH, Carbohydrazide Powder (MW 90.085 g/mol) offers three distinct advantages for coating and adhesive formulators: (1) a 48% lower equivalent weight (45.04 g/eq for Carbohydrazide vs. 87.10 g/eq for ADH), cutting the required weight of crosslinker nearly in half; (2) roughly three times higher solubility in ambient water (~320 g/L vs. ~80–120 g/L for ADH), preventing crystallization in high-solids concentrates; and (3) a shorter, stiffer C1 crosslink bridge that imparts higher film hardness, higher glass transition temperature (Tg), and superior early block resistance.

CARBOHYDRAZIDE POWDER AND THIOCARBOHYDRAZIDE

Thiocarbohydrazide (Carbonothioic dihydrazide, H2N-NH-C(=S)-NH-NH2, CAS No. 2231-57-4, MW 106.15 g/mol) is the sulfur analog of Carbohydrazide in which the carbonyl oxygen is replaced by a thione sulfur atom.
While Thiocarbohydrazide is used to synthesize sulfur-containing 1,2,4-triazole-3-thiones, 1,3,4-thiadiazoles, and electron-microscopy osmium staining reagents, it must never be used in boiler water treatment (where sulfur causes severe turbine and boiler sulfide stress corrosion) or in sulfur-free coatings. Carbohydrazide Powder (CAS 497-18-7) is 100% sulfur-free.

QUALITY GRADES, QUALITY CONTROL AND PURCHASING CRITERIA FOR CARBOHYDRAZIDE POWDER

Commercial Carbohydrazide Powder is supplied in tailored quality grades designed for water treatment, high-pressure power generation, polymer crosslinking, and chemical synthesis:
- Standard Industrial / Water-Treatment Grade (>= 98.0% or >= 99.0% Assay): Free-flowing white crystalline powder with Active Assay >= 98.0%–99.0%, Free Hydrazine <= 200 ppm (or <= 500 ppm), Moisture <= 0.5%, and Ash <= 0.1%. Used for formulating general industrial boiler oxygen scavengers, wet-layup solutions, and closed-loop corrosion inhibitors.
- Low Free-Hydrazine / High-Pressure Utility Grade (>= 99.0% Assay, Free Hydrazine <= 50–100 ppm): Produced via the dimethyl/diethyl carbonate route with thorough crystal washing and vacuum stripping to guarantee Free Hydrazine <= 50 ppm to <= 100 ppm, Moisture <= 0.2%, Ash <= 0.05%, ultra-low chloride/sulfate (< 20 ppm), and crystal-clear 10% aqueous solution (APHA <= 10–15). Engineered for high-pressure utility boilers, HRSGs, and REACH SVHC-compliant liquid scavenger formulations.
- Polymer Crosslinking & Synthesis Grade (>= 99.0%–99.5% Assay): High-purity, zero-insoluble grade (water-insolubles <= 0.02%) with tight melting range (152.5–154.0 °C) and low moisture (<= 0.2%) for 1K DAAM waterborne acrylic/PUD coatings, latent 1K epoxy curatives, and pharmaceutical/agrochemical heterocyclic synthesis.
Incoming Quality-Control (QC) Parameters to Verify on Every Shipment:
- Product Name, Manufacturer, and Synthesis Route (DMC/DEC carbonate route preferred)
- CAS No. 497-18-7 and EC / EINECS No. 207-837-2
- Active Carbohydrazide Assay (iodometric/bromometric titration or HPLC, >= 98.0% or >= 99.0%)
- Residual Free Hydrazine Content (spectrophotometric p-DMAB or GC/HPLC method, <= 50 ppm, <= 100 ppm, or <= 200 ppm as specified)
- Melting Point / Decomposition Range (capillary or DSC method, 152.0 to 154.5 °C)
- Moisture / Loss on Drying (vacuum oven at 60–65 °C, <= 0.20%–0.50% w/w)
- Residue on Ignition / Ash Content (<= 0.05%–0.10% w/w) and Trace Chloride/Sulfate
- 10% w/w Aqueous Solution Clarity, Water-Insoluble Matter (<= 0.02%–0.05%), pH (7.2–9.5), and APHA Color (<= 10–20)
Always inspect the Technical Data Sheet (TDS), 16-section Safety Data Sheet (SDS), and lot-specific Certificate of Analysis (COA) together before releasing a batch to blending or synthesis.

STORAGE AND HANDLING OF CARBOHYDRAZIDE POWDER

Store Carbohydrazide Powder in tightly sealed original moisture-barrier polyethylene-lined bags or fiber drums in a cool, dry, well-ventilated indoor warehouse maintained below 30 to 35 degrees Celsius (ideally 10 to 25 °C), away from direct sunlight, steam pipes, heaters, and open flames.
Thermal Stability and Decomposition Precautions: While Carbohydrazide Powder is stable at ambient warehouse temperatures for 12 to 24 months in sealed containers, it melts with vigorous exothermic gas-releasing decomposition at 152 to 154 degrees Celsius (and begins slow thermal degradation above 120 °C). Never store Carbohydrazide Powder near hot surfaces, boilers, or ovens, and never heat dry powder above 80–100 °C.
Segregation from Incompatible Chemicals: Strictly segregate Carbohydrazide Powder in the warehouse from oxidizing agents (hypochlorites, peroxides, nitric acid, nitrates, nitrites, chlorates, perchlorates), halogens, strong acids, and aldehydes/ketones. Reseal partially used bags immediately to prevent moisture absorption and caking.

SAFETY INFORMATION, PACKAGING AND LOGISTICS FOR CARBOHYDRAZIDE POWDER

While Carbohydrazide Powder (CAS 497-18-7) is a much safer, non-volatile solid alternative to liquid hydrazine, it is an active chemical reducing agent classified under GHS / EU CLP regulations with specific workplace and environmental hazards:
- Acute Oral Toxicity Category 4 (H302: Harmful if swallowed)
- Skin Irritation Category 2 (H315: Causes skin irritation)
- Skin Sensitization Category 1 (H317: May cause an allergic skin reaction)
- Serious Eye Irritation Category 2 (H319: Causes serious eye irritation)
- Chronic Aquatic Hazard Category 2 (H411: Toxic to aquatic life with long-lasting effects)
Note on Free Hydrazine Impurity: If a poorly refined grade contains >= 0.1% (>= 1,000 ppm) residual free hydrazine, additional GHS carcinogen classifications triggered by the hydrazine impurity may apply. Specifying low free-hydrazine Carbohydrazide Powder (<= 50 to 200 ppm N2H4) avoids impurity-driven carcinogen mixture thresholds.
Workplace Safety and Personal Protective Equipment (PPE):
Handle powder at dust-controlled charging stations with local exhaust ventilation to prevent airborne dust inhalation. Operators should wear tightly fitting safety goggles (EN 166), impervious chemical-resistant gloves (nitrile rubber, butyl rubber, or neoprene), long-sleeved protective workwear, and a particulate respirator (EN 149 FFP2 / NIOSH N95) when scooping or dumping dry powder. In case of eye or skin contact, flush immediately with plenty of running water for at least 15 minutes; if swallowed, rinse mouth and obtain immediate medical attention.
Commercial Packaging and Transport Logistics:
Carbohydrazide Powder is supplied in:
- 25 kg net multi-wall woven polypropylene or kraft paper bags with heat-sealed inner polyethylene moisture liners
- 25 kg or 50 kg net polyethylene-lined fiber drums (strongly recommended for export sea freight to prevent bag compression caking and physical damage)
- 500 kg to 1,000 kg flexible intermediate bulk containers (FIBC / big bags) with inner PE liners
Transport Classification: Depending on jurisdiction and aquatic toxicity classification, Carbohydrazide Powder is commonly transported either as UN 3077 (Environmentally hazardous substance, solid, n.o.s. (Carbohydrazide), Class 9, Packing Group III) or in accordance with Section 14 of the supplier's current SDS (note that dry Carbohydrazide must never be shipped at elevated temperatures or contaminated with oxidizers/heavy metals that could lower its self-accelerating decomposition temperature).

WHAT SHOULD BE CONSIDERED WHEN PURCHASING CARBOHYDRAZIDE POWDER?

When sourcing Carbohydrazide Powder, defining your target application, maximum allowable free hydrazine limit, and packaging format in the Request for Quotation (RFQ) ensures regulatory compliance and trouble-free dissolution:
- 1. Target Application Sector: Specify whether the powder is for formulating liquid boiler oxygen scavengers, direct power-plant feedwater dosing, 1K DAAM waterborne acrylic/PUD coating crosslinking, 1K epoxy curing, or pharmaceutical/agrochemical synthesis.
- 2. Required Active Assay and Residual Free Hydrazine Ceiling: Specify >= 98.0% or >= 99.0% Carbohydrazide assay and state your maximum free hydrazine limit (e.g., <= 50 ppm, <= 100 ppm, or <= 200 ppm N2H4).
- 3. Aqueous Solubility Clarity and Trace Impurity Limits: For liquid concentrates and clear coatings, specify water-insoluble matter <= 0.02%–0.05% and 10% aqueous solution color <= 10–20 APHA. For high-pressure utility boilers, specify ash <= 0.05% and chloride/sulfate limits.
- 4. Packaging Format (Fiber Drums vs. Bags) and Order Volume: Specify 25 kg PE-lined fiber drums or 25 kg lined bags, palletization requirements, spot shipment quantity, and annual volume forecast.
- 5. Required Documentation: Request the grade TDS, 16-section GHS SDS, and batch COA showing actual measured Assay, Free Hydrazine ppm, Moisture, Melting Point, and Ash.
Commercial pricing is driven by dimethyl carbonate and hydrazine hydrate raw-material costs, vacuum-drying and recrystallization controls required to achieve ultra-low free hydrazine (< 50–100 ppm), packaging format (fiber drums vs. woven bags), order volume, and international freight logistics.

CARBOHYDRAZIDE POWDER SUPPLY FROM ATAMAN KİMYA

Carbohydrazide Powder (Carbonic dihydrazide / 1,3-Diaminourea, CAS No. 497-18-7, EC No. 207-837-2) is supplied for boiler feedwater oxygen scavenging and steam-cycle metal passivation, closed-loop cooling/heating corrosion inhibition, ambient-temperature keto-hydrazide crosslinking of waterborne acrylic and polyurethane dispersions (PUDs), latent 1K epoxy resin curing, pharmaceutical and agrochemical heterocyclic synthesis, and aldehyde/oxidation stabilization.
Companies planning to source Carbohydrazide Powder from Ataman Kimya can share their target application and specification requirements to confirm grade suitability, residual free hydrazine limit, current stock availability, packaging options (25 kg fiber drums or 25 kg lined bags), and commercial quotation details.
Sharing the following information in a quotation request facilitates rapid technical evaluation:
- Application sector and intended final use (boiler water treatment, waterborne coating crosslinker, epoxy curative, or chemical synthesis)
- Required Carbohydrazide minimum assay (98.0% min. or 99.0% min.) and maximum residual free hydrazine limit (e.g., <= 50 ppm, <= 100 ppm, or <= 200 ppm)
- Required limits on moisture, ash / residue on ignition, chloride/sulfate, and 10% aqueous solution clarity
- Estimated order quantity (spot order and annual requirement) and preferred packaging (25 kg fiber drums vs. 25 kg PE-lined bags)
- Delivery destination and preferred Incoterms
- Required technical documents (TDS, SDS, COA) and incumbent product specification if evaluating a replacement

FREQUENTLY ASKED QUESTIONS ABOUT CARBOHYDRAZIDE POWDER

What is Carbohydrazide Powder?
Carbohydrazide Powder (also known as Carbonic dihydrazide, 1,3-Diaminourea, Carbodihydrazide, or CHZ, CAS No. 497-18-7, EC No. 207-837-2) is a white, water-soluble crystalline solid with the molecular formula CH6N4O and structural formula H2N-NH-C(=O)-NH-NH2, used primarily as a non-volatile boiler water oxygen scavenger, metal passivator, waterborne polymer crosslinker, and heterocyclic synthesis intermediate.

What is the CAS number and EC number of Carbohydrazide Powder?
The CAS Registry Number for Carbohydrazide Powder is 497-18-7, and its European Community (EC / EINECS) number is 207-837-2.

What is the molecular formula and molecular weight of Carbohydrazide?
Carbohydrazide has the molecular formula CH6N4O (condensed formula OC(NHNH2)2), a molecular weight of 90.085 g/mol, and a theoretical nitrogen content of 62.19% by weight.

Why is Carbohydrazide Powder used instead of liquid Hydrazine in boiler water treatment?
Liquid hydrazine (N2H4) is a volatile, flammable, fuming liquid classified as a Category 1B carcinogen with severe inhalation hazards. Carbohydrazide Powder is a non-volatile, non-flammable crystalline solid at room temperature that eliminates ambient hydrazine vapor exposure during handling, reacts faster with dissolved oxygen at lower temperatures (< 100–135 °C), and breaks down cleanly into hydrazine inside high-temperature boilers (> 135–180 °C) with zero dissolved solids.

How does Carbohydrazide Powder scavenge dissolved oxygen in boiler water?
At temperatures below 135 °C, Carbohydrazide reacts directly with dissolved oxygen via a 4-electron oxidation: CH6N4O + 2 O2 -> 2 N2 + CO2 + 3 H2O. Above 135–180 °C, Carbohydrazide also hydrolyzes with water into two molecules of hydrazine and carbon dioxide (CH6N4O + H2O -> 2 N2H4 + CO2), and the generated hydrazine scavenges remaining oxygen (N2H4 + O2 -> N2 + 2 H2O).

What is the stoichiometric dosage of Carbohydrazide Powder per ppm of dissolved oxygen?
Theoretically, 1.408 mg (ppm) of pure Carbohydrazide reacts completely with 1.0 mg (ppm) of dissolved oxygen (O2). In practical boiler operation, 1.5 to 3.0 ppm of Carbohydrazide is dosed per 1.0 ppm of dissolved O2, plus a small excess to maintain 0.1 to 0.5 ppm (100–500 ppb) Carbohydrazide residual at the economizer inlet.

Does Carbohydrazide Powder add Total Dissolved Solids (TDS) or conductivity to boiler water?
No. Unlike sodium sulfite (which oxidizes to non-volatile sodium sulfate solids), Carbohydrazide oxidizes exclusively into volatile gases and water (N2, CO2, and H2O), contributing zero dissolved solids and allowing its use in high-pressure utility boilers and attemperator/desuperheater spray water.

How does Carbohydrazide Powder passivate steel and copper surfaces in steam boilers?
Carbohydrazide reduces porous, corrosive red ferric oxide rust (hematite, Fe2O3) on steel surfaces into a dense, adherent black magnetite (Fe3O4) barrier film (6 Fe2O3 + CH6N4O -> 4 Fe3O4 + 2 N2 + CO2 + 3 H2O), and reduces cupric oxide (CuO) on copper/brass condenser tubes into a protective cuprous oxide (Cu2O) film.

Is Carbohydrazide Powder soluble in water?
Yes. Carbohydrazide Powder is freely soluble in water at approximately 300 to 330 g/L (~32 g per 100 mL) at 20 to 25 degrees Celsius, and its solubility increases sharply in warm water, whereas it is practically insoluble in ethanol, ether, benzene, and chloroform.

Why does the water cool down when dissolving Carbohydrazide Powder?
Dissolving crystalline Carbohydrazide Powder in water is an endothermic process because energy is absorbed to break the strong intermolecular hydrogen bonds of the crystal lattice. Using warm deionized water (25 to 35 °C) offsets this cooling effect and accelerates complete dissolution.

What concentration of liquid Carbohydrazide is typically prepared from Carbohydrazide Powder?
Water-treatment formulators typically dissolve Carbohydrazide Powder at 5.0% to 12.0% w/w (most commonly 6%, 8%, or 10% w/w) in deionized water so that the liquid product remains crystal-free during cold winter transport down to 0 °C.

Why is Hydroquinone sometimes added to aqueous Carbohydrazide solutions?
Adding 0.05% to 0.25% w/w Hydroquinone acts as a quinone/hydroquinone redox electron-transfer catalyst that dramatically accelerates the reaction rate of Carbohydrazide with dissolved oxygen at low water temperatures (20 to 80 °C), such as in cold make-up water, wet boiler layups, and closed cooling loops.

What is the melting point and decomposition temperature of Carbohydrazide Powder?
Carbohydrazide Powder melts at approximately 152.0 to 154.5 degrees Celsius accompanied by vigorous exothermic thermal decomposition that releases nitrogen, ammonia, carbon oxides, and water vapor. Dry powder should never be heated above 100–120 °C.

Why is residual Free Hydrazine content important on a Carbohydrazide Powder COA?
Because free hydrazine (N2H4) is a regulated carcinogen and EU REACH SVHC (when present at >= 0.1% / 1,000 ppm), specifying Carbohydrazide Powder with residual free hydrazine <= 50 ppm to <= 200 ppm ensures safe operator handling and keeps both the powder and its aqueous dilutions below carcinogen mixture classification limits.

How is Carbohydrazide Powder manufactured industrially?
High-purity Carbohydrazide Powder is manufactured primarily by reacting dimethyl carbonate (DMC) or diethyl carbonate (DEC) with hydrazine hydrate at 60–95 °C, distilling off the alcohol by-product under reduced pressure, crystallizing Carbohydrazide at 5–15 °C, centrifuging, and vacuum-drying the crystals at 60–75 °C.

How does Carbohydrazide Powder work as a crosslinker in waterborne acrylic and polyurethane coatings?
In one-component (1K) waterborne dispersions containing copolymerized diacetone acrylamide (DAAM) ketone groups, Carbohydrazide remains stable in the alkaline water phase during storage; upon coating application and water evaporation, its two terminal -NHNH2 groups condense with the polymer ketone groups at room temperature to form covalent dihydrazone (-C=N-NH-C(=O)-) crosslinks.

What is the advantage of Carbohydrazide Powder over Adipic Dihydrazide (ADH) in DAAM coatings?
Carbohydrazide has a molecular weight of 90.085 g/mol (equivalent weight 45.04 g/eq) compared to 174.20 g/mol (equivalent weight 87.10 g/eq) for ADH—meaning almost 50% less weight of Carbohydrazide is required to crosslink the same amount of DAAM, while providing 3x higher water solubility (~320 g/L vs. ~100 g/L) and higher film hardness and Tg.

How is Carbohydrazide Powder used in one-component (1K) epoxy resins?
Because Carbohydrazide Powder melts at 152–154 °C and is insoluble in liquid epoxy resins at room temperature, micronized Carbohydrazide acts as a solid latent thermal curing agent (equivalent weight 22.52 g per active N-H) that cures epoxy adhesives and powder coatings at 115–145 °C while providing multi-month ambient shelf stability.

Can Carbohydrazide Powder scavenge formaldehyde in wood adhesives and textiles?
Yes. The nucleophilic hydrazide (-NHNH2) groups react rapidly and irreversibly with free formaldehyde to form non-volatile hydrazone and cyclic triazolidinone derivatives, reducing formaldehyde emissions from urea-formaldehyde and melamine-formaldehyde resins.

What is Carbohydrazide Powder used for in pharmaceutical and agrochemical synthesis?
It serves as a symmetrical C1 hydrazide building block to synthesize 1,2,4-triazin-5-one herbicides (such as metamitron and metribuzin intermediates), 1,2,4-triazole fungicides, 1,3,4-oxadiazoles, and cephalosporin/beta-lactam antibiotic intermediates.

Why is Carbohydrazide Powder used in airbag gas generants and energetic materials?
With a high nitrogen content of 62.19% w/w, strong chelating ability toward metal cations, and clean oxidation into non-toxic N2, CO2, and H2O gases, Carbohydrazide is used to manufacture automotive airbag gas generants, propellant stabilizers, and lead-free energetic coordination complexes.

CARBOHYDRAZIDE POWDER – TECHNICAL SUMMARY

Carbohydrazide Powder, known in Turkish as Karbohidrazid Toz or Karbonik Dihidrazid and registered globally under CAS No. 497-18-7 and EC / EINECS No. 207-837-2 (Carbonic dihydrazide / 1,3-Diaminourea), is a symmetrical nitrogen-rich organic reducing agent and bifunctional nucleophile with the molecular formula CH6N4O (H2N-NH-C(=O)-NH-NH2) and a molecular weight of 90.085 g/mol. Manufactured primarily via the condensation of dimethyl or diethyl carbonate with hydrazine hydrate followed by crystallization and vacuum drying, it is supplied in >= 98.0% and >= 99.0% purity grades as a white, odorless, free-flowing crystalline powder with a melting/decomposition range of 152 to 154 degrees Celsius and high water solubility (~320 g/L at 20 °C).
Developed as a safe, non-volatile, non-flammable solid replacement for carcinogenic liquid hydrazine in industrial and utility steam generation, Carbohydrazide Powder scavenges dissolved oxygen across both low- and high-temperature regimes (1.41 mg Carbohydrazide per 1.0 mg O2) while converting entirely into volatile N2, CO2, and H2O with zero contribution to boiler water Total Dissolved Solids (TDS). Simultaneously, it reduces porous red ferric oxide (Fe2O3) into a dense, protective black magnetite (Fe3O4) film on boiler steel and reduces cupric oxide (CuO) to cuprous oxide (Cu2O) on copper-alloy condenser tubes.

Beyond boiler feedwater, wet layup, and closed-loop corrosion control, Carbohydrazide Powder serves as a low-equivalent-weight (45.04 g/eq) ambient-temperature keto-hydrazide crosslinker for diacetone acrylamide (DAAM) modified 1K waterborne acrylic and polyurethane coatings, a latent thermal hardener for 1K epoxy resins, a formaldehyde/aldehyde scavenger in wood resins, soaps, and synthetic fibers, and a key C1 heterocyclic synthon for 1,2,4-triazinone herbicides, triazole fungicides, cephalosporin antibiotics, and energetic coordination complexes.
Buyers sourcing Carbohydrazide Powder from Ataman Kimya are advised to specify their target application, required active assay (>= 98.0% or >= 99.0%), maximum residual free hydrazine limit (<= 50 ppm, <= 100 ppm, or <= 200 ppm), ash and trace halide ceilings, packaging preference (25 kg PE-lined fiber drums or 25 kg multi-wall bags), and order quantity to confirm current availability and quotation details.

Ataman Chemicals
Phone: +90 216 577 10 10
Email: info@atamankimya.com