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N,N-Diethylhydroxylamine (DEHA): Chemistry, Industrial Applications, and Quality Standards
N,N-Diethylhydroxylamine — commonly abbreviated as DEHA and registered under CAS No. 3710-84-7 — is a versatile hydroxylamine derivative that has become a cornerstone specialty chemical in several industrial sectors. From boiler water treatment to monomer stabilization and photographic processing, DEHA's combined antioxidant, oxygen-scavenging, and corrosion-inhibiting capabilities make it uniquely valuable. This article provides a comprehensive technical overview of DEHA: its molecular characteristics, published specifications, key application areas, handling requirements, and a look at the reliable supply offered by Jiaxing Jinli Chemical Co., Ltd.
1. Molecular Structure and Physical Chemistry
DEHA belongs to the class of N,N-dialkylhydroxylamines, where the two ethyl groups are attached directly to the nitrogen of the hydroxylamine moiety (HO–N(C₂H₅)₂). This substitution pattern is structurally significant: the nitrogen lone pair and the N–O bond together give DEHA its free-radical-trapping ability, while the diethyl groups confer sufficient lipophilicity for compatibility with a wide range of industrial media.
| Property | Value / Description |
|---|---|
| IUPAC Name | N,N-diethylhydroxylamine |
| Common Abbreviation | DEHA |
| CAS Registry Number | 3710-84-7 |
| Molecular Formula | C₄H₁₁NO |
| Molecular Weight | 89.14 g/mol |
| Functional Group | N,N-disubstituted hydroxylamine |
| Physical State (ambient) | Colorless to light yellow liquid |
| Solubility | Fully miscible with water, alcohols, and common polar solvents |
| Boiling Point (pure) | ≈ 126 °C at 760 mmHg (literature value) |
| pKₐ (conjugate acid) | ≈ 5.96 (weakly basic nitrogen) |
Physical property data compiled from open chemical databases (PubChem CID 68596, ChemSpider). Confirm with the supplier's Safety Data Sheet for the specific commercial grade in use.
2. Commercial Specifications
Industrial DEHA is typically supplied as an aqueous solution rather than the neat compound, which simplifies handling and moderates flammability risk. The specification table published by Jinli Chemical defines the following quality parameters for their commercial grade:
| Parameter | Unit | Specification |
|---|---|---|
| Appearance | — | Colorless to light yellow liquid |
| Purity (DEHA content) | % min | 85 |
| Water content | % max | 15 |
| Diethylamine (DEA) impurity | % max | 1.0 |
| Colority (APHA / Pt–Co scale) | Pt/Co max | 70 |
The APHA color limit of 70 Pt/Co is a relatively strict criterion for an amine-class product. Slight yellowing typically signals early oxidation of the hydroxylamine moiety; maintaining color within this window confirms the product's antioxidant capacity has not been prematurely consumed during storage or transit.
3. Reaction Mechanisms Behind DEHA's Multifunctionality
3.1 Oxygen Scavenging in Aqueous Systems
Dissolved oxygen is the primary driver of pitting corrosion in carbon-steel boiler circuits. DEHA reacts with oxygen in a stoichiometric, non-catalytic pathway, converting molecular O₂ to water and forming the corresponding N-oxide (diethylhydroxylamine N-oxide), which is itself water-soluble and non-hazardous. Unlike sulfite-based scavengers, this reaction produces no ionic solids that could contribute to deposit formation.
3.2 Free-Radical Inhibition for Monomer Stabilization
In vinyl and acrylic monomer streams, spontaneous polymerization is initiated by peroxy or carbon-centered free radicals. DEHA intercepts these radicals at the N–O bond, forming a stable nitroxide intermediate that terminates the chain. This mechanism is essentially the same as that of hindered nitroxides used in controlled radical polymerization, making DEHA highly effective at sub-ppm to low-ppm concentration levels.
3.3 Passivation of Metal Surfaces
At elevated temperatures (above roughly 80 °C), DEHA participates in the formation of a magnetite (Fe₃O₄) passivation layer on steel surfaces through a reduction–oxidation interaction with ferric ions. This protective oxide layer dramatically reduces further corrosion and also aids in conditioning iron oxide deposits already present in aging circuits.
4. Key Industrial Applications
| Sector | Role of DEHA | Typical Use Level |
|---|---|---|
| Boiler & Steam Systems | Oxygen scavenger, passivator, corrosion inhibitor in feedwater | 2–20 mg/L (feedwater) |
| Monomer Stabilization | Free-radical inhibitor for vinyl, acrylic, and styrene monomers | 10–200 ppm in monomer |
| Photographic Chemicals | Antioxidant and preservative in developer solutions | Formulation-dependent |
| Semiconductor Processing | Photoresist stripping aid; metal-surface passivation | Dilute aqueous blends |
| Agrochemical Synthesis | Intermediate for synthesis of hydroxamic acids and herbicide actives | Stoichiometric reagent |
| Rubber & Polymer Antioxidants | Stabilizer during storage of latex and rubber pre-forms | 100–500 ppm |
4.1 Water Treatment: A Closer Look
High-pressure boiler systems operating above 40 bar require exceptionally low levels of dissolved oxygen (typically below 7 ppb) to prevent catastrophic pitting. DEHA became popular as a replacement for hydrazine — a known carcinogen — in the 1980s and 1990s, offering comparable efficacy without the acute toxicity profile. Modern combined all-organic treatment (AVT-O and OT programs) increasingly specify DEHA as the oxygen scavenger of choice in power generation and process steam applications.
4.2 Monomer Inhibition in the Petrochemical Industry
During the storage and transportation of reactive monomers such as acrylic acid, methyl acrylate, and styrene, uncontrolled polymerization poses severe safety risks including exothermic runaways. DEHA's effectiveness even in the absence of dissolved oxygen sets it apart from purely oxygen-dependent inhibitors like hydroquinone (HQ) or methyl hydroquinone (MEHQ), making it a preferred choice for oxygen-free or low-oxygen storage tanks.
5. Handling, Storage, and Safety Summary
Responsible handling of DEHA requires understanding its hazard classification. While considerably safer than hydrazine, DEHA should be managed with appropriate engineering controls. The following summary is intended for general guidance only; always consult the current Safety Data Sheet (SDS) from your supplier before handling.
| Parameter | Guidance |
|---|---|
| GHS Classification | Harmful if swallowed (Acute Tox. 4); Skin / eye irritant |
| PPE | Chemical-resistant gloves, safety goggles, appropriate respiratory protection |
| Storage Temperature | Cool, well-ventilated area; avoid temperatures above 40 °C |
| Container Material | HDPE, stainless steel, or lined carbon steel; avoid copper alloys |
| Shelf Life | Typically 12–24 months when stored cool and away from oxidizers |
| Incompatibilities | Strong acids, strong oxidizing agents, reactive metals |
| Spill Response | Dilute with large volumes of water; collect and dispose per local regulations |
Safety data presented here is a generalized summary. Refer to the current SDS provided by Jinli Chemical or your local regulatory authority for authoritative guidance.
6. DEHA vs. Alternative Oxygen Scavengers
| Chemical | Mechanism | Advantages over DEHA | Disadvantages vs. DEHA |
|---|---|---|---|
| Hydrazine (N₂H₄) | Reductive; stoichiometric with O₂ | Very fast reaction kinetics | Carcinogen; severely restricted in many countries |
| Sodium Sulfite (Na₂SO₃) | Reductive; catalyzed by Co²⁺ | Low cost; rapid | Increases TDS; forms sulfate deposits; not suitable above 40 bar |
| Erythorbic Acid | Reducing organic acid | Food-grade accepted | Less effective passivator; pH-sensitive |
| Carbohydrazide | Reductive; decomposes to N₂ + CO₂ | Volatile products; all-volatile program compatible | Higher cost than DEHA |
| DEHA | Free-radical scavenger + reductive | Low toxicity; passivates steel; no ionic by-products | Slower kinetics at very low temperatures |
7. About Jiaxing Jinli Chemical Co., Ltd.
Jiaxing Jinli Chemical Co., Ltd. was established in 2002 and relocated in 2011 to the Zhejiang Province Zhapu Economic Development Park, located in the Jiaxing Port Area at the north bank of Hangzhou Bay — approximately 105 km from Shanghai and 110 km from Hangzhou. The facility covers 22,000 m² and holds an annual production capacity of approximately 19,000 tonnes.
Jinli Chemical has been certified as a National High-Tech Enterprise and holds the ISO 9001, ISO 14001, and ISO 45001 management system certifications — reflecting its commitment to quality, environmental responsibility, and occupational safety. The company maintains industry–university–research partnerships with Zhejiang University of Technology and Jiaxing University.
Products are exported to the USA, EU, South Korea, Japan, and Southeast Asia. Jinli Chemical's product portfolio spans:
- Forming Agent & Blowing Agent Series
- Plasticizer Series
- Intermediates Series
- Disinfector Series
- Other Specialty Chemicals (including DEHA)
Contact: +86-573-85580888 | Intersection of Pinghai Road and Binhai Avenue, Jiaxing Port Area Chemical Park | Enquiry Form
N,N-Diethylhydroxylamine (DEHA, CAS 3710-84-7) occupies a well-established position in the global specialty chemicals market, offering a rare combination of oxygen-scavenging, free-radical-inhibiting, and metal-passivating functionality within a single, relatively low-toxicity molecule. As regulatory pressure continues to restrict the use of legacy chemistries such as hydrazine and high-dose sulfite programs, DEHA is expected to see sustained or growing demand in boiler water treatment, monomer stabilization, and advanced electronics cleaning applications.
Sourcing DEHA from a certified, technically oriented manufacturer is critical. With its ISO-certified production facility, established R&D partnerships, and proven export track record, Jiaxing Jinli Chemical Co., Ltd. offers a credible and quality-assured supply of commercial-grade DEHA for both domestic Chinese customers and international buyers. Interested parties are encouraged to visit the official DEHA product page or reach out via the contact page for specifications, pricing, and sampling inquiries.