DIISOPROPANOLAMINE (DIPA)

1. Chemical Identity and Material Classification

Chemical Name: Diisopropanolamine, 1,1'-Iminodi-2-propanol
Synonyms: DIPA, Bis(2-hydroxypropyl)amine, 2,2'-Dihydroxydipropylamine, Di-2-propanolamine
CAS Number: 110-97-4
Molecular Formula: C₆H₁₅NO₂
Molecular Weight: 133.19 g/mol
EC Number (EINECS): 203-820-9
MDL Number: MFCD00004531
Chemical Class: Secondary alkanolamine (secondary amine + diol)
INCI Name: Diisopropanolamine
UNII: 0W44HYL8T5
Beilstein Registry Number: 605363

2. Physical Properties

2.1 General Physical Properties

Property	Value
Appearance (20°C)	White to pale yellow crystalline solid
Physical state (20°C)	Solid (melts slightly above room temperature)
Odor	Fishy, ammoniacal (characteristic amine odor)
Melting point	42–45°C (108–113°F) – note: supercools; varies with grade
Boiling point (at 760 mmHg)	249–250°C (480–482°F)
Density (at 25°C)	1.004 g/cm³ (8.46 lb/gal at 25°C)
Specific gravity (water = 1)	0.99–1.004
Vapor pressure (at 20°C)	0.02 hPa (0.015 mmHg)
Vapor pressure (at 50°C)	0.035 mmHg
Vapor density (air = 1)	>1 (heavier than air)
Refractive index (nD20)	1.4615–1.4635
Flash point (closed cup)	126–135°C (259–275°F) – combustible
Autoignition temperature	290–370°C (554–698°F)
Explosive limits (vol% in air)	Lower: 1.1–1.6%; Upper: 5.4–8.0%

2.2 Thermal Properties

Parameter	Value
Heat of combustion	Not specified
Decomposition temperature	>250°C (slow decomposition)
pKa (25°C)	14.54 ± 0.20 (predicted)

3. Solubility and Solution Properties

3.1 Solubility in Various Solvents

Solvent	Solubility	Temperature
Water	870 g/L (1200 g/L per Dow)	20–25°C
Water	Completely miscible	20°C
Acetone	810 g/L	25°C
Methanol	670 g/L	25°C
Ethanol	9 g/L	25°C
Organic solvents	Miscible with polar solvents	20°C

3.2 Aqueous Solution Properties

Parameter	Value
pH (100 g/L solution, 20°C)	11.4 (strongly alkaline)
pH (870 g/L saturated solution)	~11–12
Surface tension (at 50°C, 323.15K)	34.5 mN/m
Viscosity (at 60°C)	84.19 mPa·s (cps)
log P (octanol/water)	-0.79 to -0.82 (very hydrophilic)

4. Chemical Properties

4.1 Molecular Structure

DIPA is a secondary alkanolamine consisting of:

Two isopropanol groups (2-hydroxypropyl) attached to a central nitrogen atom
One secondary amine group (N-H) – reacts with acids, CO₂, H₂S, isocyanates
Two primary alcohol groups (OH) – undergo typical alcohol reactions

Structure: HOCH₂CH(CH₃)-NH-CH(CH₃)CH₂OH (branched)

4.2 Chemical Reactivity

Reaction Type	Description
Acid neutralization	Forms amine salts with mineral and organic acids
CO₂ absorption	Forms carbamate salts (key for gas sweetening)
H₂S absorption	Forms amine sulfides (gas purification)
Esterification	With fatty acids → alkanolamide emulsifiers
Quaternization	With alkylating agents → quaternary ammonium compounds
Epoxy reactions	Reacts with epoxides → polyols
Isocyanate reaction	Forms urethanes (polyurethane catalysts/intermediates)

4.3 Carbamate Formation (Gas Sweetening Mechanism)

Reaction: 2R₂NH + CO₂ ⇌ R₂NH₂⁺ + R₂NCOO⁻ (carbamate salt)

DIPA is particularly effective for CO₂ and H₂S removal via this reversible reaction, enabling solvent regeneration.

4.4 Stability

Parameter	Behavior
Stability	Stable under normal conditions
Hygroscopicity	Hygroscopic (absorbs moisture from air)
Air sensitivity	Turns yellow upon prolonged exposure to light and air (oxidation)
Storage stability	Stable; discoloration does not affect performance

4.5 Incompatibilities

Strong oxidizing agents
Strong acids (exothermic neutralization)
Acid anhydrides and acid chlorides
Isocyanates
Carbon dioxide (forms solid carbamate under certain conditions)

5. Quality Specifications

5.1 Commercial Grade (DIPA)

Parameter	Specification
Purity (DIPA, w/w)	≥ 95–99% (depending on grade)
Water content	≤ 0.5% (anhydrous grade)
Color (APHA)	≤ 50 (fresh; may yellow with age)
Melting point	42–45°C
Equivalent weight	133.19 g/eq
Freezing point (anhydrous)	44°C (111.2°F) – supercools; shows variation

5.2 Low Freeze Grade (DIPA LFG 90)

Parameter	Specification
Composition	90% DIPA + 10% deionized water
Freezing point	23°C (73.4°F)
Density (at 25°C)	1.015 g/cm³
Viscosity (at 25°C)	790 cP
Form at 20°C	Liquid (easier handling in cold climates)

5.3 Low Freeze Grade (DIPA LFG 85)

Parameter	Specification
Composition	85% DIPA + 15% deionized water
Freezing point	13°C (55.4°F)
Density (at 25°C)	1.019 g/cm³
Viscosity (at 25°C)	450 cP
Form at 20°C	Liquid (easiest handling in cold climates)

6. Production Methods

6.1 Reaction of Ammonia with Propylene Oxide

Reaction: NH₃ + 2CH₃CH(O)CH₂ → (HOCH₂CH(CH₃))₂NH
Process: Ammonia reacts with propylene oxide under controlled conditions → mixture of mono-, di-, and triisopropanolamines → separation by distillation
Coproducers: Monoisopropanolamine (MIPA) and Triisopropanolamine (TIPA)

6.2 Purification

Distillation under reduced pressure
Filtration to remove particulates

7. Industrial Applications

7.1 Gas Treating (Sulfinol Process – Primary Application)

Parameter	Value
Application	Removal of acid gases (CO₂, H₂S) from natural gas, refinery gas, synthesis gas
Typical concentration	40–45% DIPA in Sulfinol solvent
Process type	Regenerable amine scrubbing
Mechanism	DIPA forms reversible carbamate/sulfide salts at low temperature; releases acid gases upon heating
Advantages	High capacity, low degradation, selective H₂S removal

7.2 Metalworking Fluids

Parameter	Value
Application	Tall oil amides for water-based metalworking fluids
Function	Corrosion protection, lubricity improvement, foam suppression, friction reduction
Derivative	DIPA + tall oil fatty acid → tall oil amide

7.3 Surfactants and Emulsifiers

Parameter	Value
Application	Neutralization of fatty acids and sulfonic acid-based surfactants
End products	Detergents, emulsifiers, dispersants, wetting agents
Benefits	Good solubilizer of oils and fats

7.4 Cement Grinding Aids

Parameter	Value
Application	Additive in cement production to improve grinding efficiency
Function	Prevents agglomeration of cement particles
Typical dosage	0.01–0.1% by weight of cement

7.5 Corrosion Inhibitors

Parameter	Value
Application	Corrosion protection in metal processing, cooling water systems, cutting fluids
Mechanism	Forms protective film on metal surfaces

7.6 Polyurethane Catalysts

Parameter	Value
Application	Catalyst for polyurethane foam production (rigid and flexible foams)
Function	Promotes reaction between isocyanates and polyols

7.7 Coatings and Paints

Application	Function
Paint strippers	Neutralizes acidic components, acts as solvent
Coating formulations	Neutralizing agent, pH adjuster
Electrodeposition coatings	Used in cathodic electrocoat (E-coat) systems

7.8 Personal Care and Cosmetics

Parameter	Value
Function	pH adjuster, emulsifier, buffering agent
CIR status	Approved for cosmetic use
Typical products	Shampoos, conditioners, lotions, creams

7.9 Textile Industry

Parameter	Value
Application	Dyeing auxiliaries, finishing agents, scouring agents
Function	pH control, emulsification

7.10 Agricultural Chemicals

Parameter	Value
Application	Neutralization of acidic herbicides (e.g., 2,4-D, glyphosate)
Function	Forms water-soluble amine salts

7.11 Carbon Capture

Parameter	Value
Application	CO₂ capture from flue gas and industrial emissions
Mechanism	DIPA enhances CO₂ solubility in blended amine solutions
Advantages	Higher absorption capacity than MEA alone

7.12 Pharmaceuticals

Parameter	Value
Application	Chemical intermediate for active pharmaceutical ingredients (APIs)
Function	Building block for synthesis

7.13 Other Applications

Sector	Application
Paper industry	Coating additives, paper processing
Photography	Photographic chemical intermediates
Plastics	Plasticizers, stabilizers
Urethanes	Polyurethane additives, reaction intermediates

8. Comparison with Similar Alkanolamines

Property	DIPA (Diisopropanolamine)	DEA (Diethanolamine)	MEA (Monoethanolamine)
Structure	C₆H₁₅NO₂	C₄H₁₁NO₂	C₂H₇NO
Molecular weight	133.19	105.14	61.08
Melting point	42–45°C	28°C	10.5°C
Boiling point	249–250°C	268°C	170°C
Basicity	Moderate	High	Very high
Gas treating selectivity	Higher for H₂S	Moderate	Low
Viscosity at 20°C	High (solid)	High	Low
Biodegradability	Biodegradable	Biodegradable	Biodegradable

9. Toxicology and Safety

9.1 Acute Toxicity

Parameter	Value
Oral LD₅₀ (rat)	4,765 mg/kg (moderately toxic)
Dermal LD₅₀ (rabbit)	8,000 mg/kg
Intraperitoneal LD₅₀ (mouse)	96 mg/kg

9.2 Irritation and Sensitization

Endpoint	Classification
Skin irritation	Not classified as irritant (based on available data)
Eye irritation	Category 2 – Causes serious eye irritation
Skin sensitization	Not a skin sensitizer
Respiratory sensitization	Not a respiratory sensitizer

9.3 Chronic Toxicity

Endpoint	Classification
Carcinogenicity	Not classified as carcinogen (IARC/OSHA/ACGIH: not listed)
Mutagenicity	Not mutagenic (AMES test negative)
Reproductive toxicity	Not classified
STOT – single exposure	Not classified
STOT – repeated exposure	Not classified

9.4 Environmental Information

Parameter	Value
Biodegradability	Readily biodegradable
Ecotoxicity (fish)	Low to moderate toxicity
Bioaccumulation	Low potential (log P < 1)
WGK Germany	1 (low hazard to water)

9.5 Regulatory Information

Region	Status
TSCA (US)	Listed
REACH (EU)	Registered (active)
FDA	Permitted for certain indirect food contact uses
EU Cosmetics	Permitted as pH adjuster/emulsifier
Canada DSL	Listed
Australia AICS	Listed

10. GHS Classification

Classification	Category
Signal word	Warning
Hazard statements	H319 – Causes serious eye irritation
Precautionary statements	P264, P280, P305+P351+P338, P337+P313
NFPA health	2
NFPA flammability	0
NFPA instability	0

11. Safety Precautions and Personal Protective Equipment (PPE)

Hazards:
- Causes serious eye irritation (H319)
- Hygroscopic – absorbs moisture from air
- May cause respiratory tract irritation if heated (vapors)
- Combustible – keep away from ignition sources
PPE (recommended):
- Chemical safety goggles (EN 166) – mandatory due to eye hazard
- Chemical-resistant gloves (nitrile or neoprene)
- Protective clothing (chemical-resistant)
- Respiratory protection: Type K (green) filter for ammonia derivatives if ventilation inadequate
Engineering controls:
- Local exhaust ventilation (LEV) for heated applications
- Eyewash stations and safety showers in immediate vicinity
First aid:
- Eye contact: Rinse immediately with water for at least 15 minutes; remove contact lenses; get medical attention
- Skin contact: Wash off immediately with soap and plenty of water; remove contaminated clothing
- Inhalation: Remove to fresh air; if not breathing, give artificial respiration
- Ingestion: Rinse mouth; do NOT induce vomiting; get medical attention

12. Handling and Storage

12.1 Handling Precautions

Parameter	Recommendation
Ventilation	Use adequate ventilation (local exhaust for heated applications)
Personal hygiene	Wash thoroughly after handling; do not eat, drink, or smoke in work area
Spill response	Sweep up or absorb with inert material; avoid dust generation

12.2 Storage Conditions

Parameter	Requirement
Temperature	Store below 30°C (room temperature)
Container	Keep tightly closed in original container
Atmosphere	Store under inert atmosphere (nitrogen) to prevent oxidation/discoloration
Incompatibles	Separate from strong oxidizing agents, strong acids, acid chlorides, isocyanates
Environment	Cool, dry, well-ventilated area

12.3 DIPA LFG 85/LFG 90 Storage

Parameter	Requirement
Temperature	Store above freezing point to maintain liquid state
Freezing point LFG90	23°C – store >23°C to prevent crystallization
Freezing point LFG85	13°C – store >13°C to prevent crystallization

13. Transport Information

Regulation	Classification
UN Number	3259 (for solid amine) – check local regulations
ADR/RID	Class 8 (Corrosive), Packing group III (for solid)
DIPA LFG85/LFG90 (solution)	Not hazardous material for transport (per DOT)
DOT classification	Not regulated as hazardous material for many grades
Hazard class	8 (Corrosive) for anhydrous solid
Proper shipping name	Amines, solid, corrosive, n.o.s. or Diisopropanolamine

14. Synonyms and Common Names

English: Diisopropanolamine, DIPA, 1,1'-Iminodi-2-propanol, Bis(2-hydroxypropyl)amine, 2,2'-Dihydroxydipropylamine, Di-2-propanolamine
Trade names: DIPA Commercial Grade, DIPA LFG 85, DIPA LFG 90
Supplier trade names: Dequest, Proninol, Isopropanolamine blends
Chemical names: 1-(2-Hydroxypropylamino)propan-2-ol; N,N-Bis(2-hydroxypropyl)amine

15. Regulatory Status

Regulation	Status
REACH (EC 1907/2006)	Registered (active)
TSCA (US)	Listed
EINECS	203-820-9
FDA	Indirect food contact permitted
EU Cosmetics Regulation	Permitted as pH adjuster/emulsifier
EPA (US)	Listed as inert ingredient (40 CFR 180.950 – minimal risk)

16. Why Choose Diisopropanolamine? (Technical Summary)

Advantage	Description
Effective acid gas removal	Key component in Sulfinol process for natural gas sweetening (CO₂, H₂S)
Branched secondary amine structure	Higher selectivity for H₂S over CO₂ compared to MEA/DEA
Good thermal stability	Low degradation rates compared to primary amines
Excellent emulsifier	Forms stable amides with fatty acids for metalworking fluids
Low corrosivity	Less corrosive than MEA and DEA in gas treating applications
Hygroscopic (low freeze grades available)	LFG85/LFG90 enable liquid handling in cold climates
Biodegradable	Environmentally friendly; readily biodegradable
Versatile chemical intermediate	Used in surfactants, polyurethanes, corrosion inhibitors, cement grinding aids
pH adjustment capability	Effective neutralizing agent for acids; buffer capacity
Cost-effective	Lower cost than specialized amines for many applications

Limitations:

Solid at room temperature – requires heated storage or use of LFG grades for cold climates
High viscosity – even LFG grades have high viscosity at lower temperatures
Eye irritation hazard – requires appropriate PPE (goggles)
Hygroscopic – absorbs moisture, affecting handling and storage
May discolor upon prolonged air/light exposure – yellowing does not affect performance for most applications but may be undesirable for certain uses

17. Typical Applications Summary Table

Sector	Application	Typical Concentration/Usage	Alternatives
Natural Gas	Acid gas removal (Sulfinol process)	40–45% of solvent	MDEA, DIPA (also used), DEA
Metalworking	Corrosion inhibitor, lubricity additive (as tall oil amide)	5–20% in concentrate	DEA, TEA
Cement	Grinding aid	0.01–0.1% by weight of cement	TEA, glycols, other alkanolamines
Detergents	Surfactant intermediate, emulsifier	2–10% in formulations	DEA, MEA
Polyurethanes	Catalyst, reaction intermediate	0.1–2%	Other tertiary amines
Paints/Coatings	Neutralizing agent, pH adjuster	0.1–1%	AMP, other alkanolamines
Cosmetics	pH adjuster, emulsifier	0.5–5%	TEA, AMP
Agriculture	Herbicide neutralization (2,4-D, glyphosate)	Stoichiometric	Other amine salts
Carbon Capture	CO₂ absorption promoter	10–30% in blends	MEA, MDEA, PZ
Textiles	Dye auxiliaries, finishing agents	1–10 g/L	Other alkanolamines

18. Product Grades Availability

Grade	Composition	Form at 20°C	Freezing Point	Applications
DIPA Commercial Grade (Anhydrous)	≥ 95–99% DIPA	Solid (crystalline)	44°C (supercools)	General industrial, gas treating, chemical synthesis
DIPA LFG 90	90% DIPA + 10% water	Liquid	23°C	Cold climates, easy handling
DIPA LFG 85	85% DIPA + 15% water	Liquid	13°C	Cold climates, easiest handling
DIPA low purity	>90% DIPA (with isomers)	Solid	~40°C	Cost-effective for less demanding applications

19. Environmental Information

Parameter	Value
Biodegradability	Readily biodegradable
Hydrolysis	Not applicable (does not hydrolyze in water)
Bioaccumulation	Low (BCF < 100; log P < 1)
Aquatic toxicity (fish)	100–500 mg/L (low to moderate)
WGK classification	1 (low hazard to water) – Germany

20. Summary Table – Key Specifications at a Glance

Parameter	Value
Product Name	Diisopropanolamine (DIPA)
CAS Number	110-97-4
Molecular Formula	C₆H₁₅NO₂
Molecular Weight	133.19 g/mol
Appearance (20°C)	White to pale yellow crystalline solid
Odor	Fishy, ammoniacal
Melting Point	42–45°C (108–113°F)
Boiling Point	249–250°C (480–482°F)
Density	1.004 g/cm³ at 25°C
Flash Point	126–135°C (259–275°F)
pH (100 g/L solution)	11.4 (strongly alkaline)
Water Solubility	870 g/L (fully miscible)
log P	-0.79
Primary Applications	Gas sweetening, metalworking fluids, cement grinding aids, surfactants, coatings
GHS Signal Word	Warning
Hazard Statement	H319 – Causes serious eye irritation
Biodegradability	Readily biodegradable

This TDS is prepared in compliance with ISO 11014-1 format and is intended for gas processing engineers, metalworking fluid formulators, cement industry professionals, surfactant chemists, and procurement specialists. Certificates of Analysis (CoA), Safety Data Sheets (SDS), and sample validation reports are available upon request.

Diisopropanolamine, Diisopropanol Amine, DIPA, 110-97-4