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Send EmailNeopentyl Glycol, Dimethylpropane Diol, Dimethylol Propane, NPG, 126-30-7
Neopentyl Glycol / 2,2-Dimethylpropane-1,3-diol / NPG
CAS Number: 126-30-7
EC Number: 204-781-0
| Parameter | Information |
|---|---|
| Product Name | Neopentyl Glycol |
| Abbreviation | NPG |
| Chemical Name (IUPAC) | 2,2-Dimethylpropane-1,3-diol |
| Other Names | Neopentyl Glycol, 2,2-Dimethyl-1,3-propanediol, Dimethylolpropane |
| CAS Number | 126-30-7 |
| EC Number (EINECS) | 204-781-0 |
| Molecular Formula | C₅H₁₂O₂ |
| Molecular Weight | 104.15 g/mol |
| Chemical Class | Diol (aliphatic glycol) |
| Appearance | White crystalline solid |
| Odor | Practically odorless |
| Physical State (20°C) | Solid (crystalline) |
Neopentyl Glycol (NPG) is a white crystalline diol with a unique structure featuring two hydroxymethyl groups attached to a central carbon atom with two methyl substituents. This "neopentyl" structure imparts excellent thermal stability, oxidation resistance, and chemical resistance to its derivatives. It is widely used in the production of high-performance polyester resins, alkyd resins, plasticizers, lubricants, and coatings.
| Type | Name |
|---|---|
| Common Names | Neopentyl Glycol, NPG |
| Chemical Names | 2,2-Dimethylpropane-1,3-diol, 2,2-Dimethyl-1,3-propanediol, Dimethylolpropane |
| CAS Number | 126-30-7 |
| EC Number | 204-781-0 |
| HS Code | 2905.39 |
Neopentyl Glycol is a diol with two primary hydroxyl groups attached to a neopentyl carbon skeleton. The central carbon is bonded to two methyl groups and two hydroxymethyl groups.
Structural Formula:
CH₂OH
|
CH₃ - C - CH₃
|
CH₂OH
Simplified Representation:
(CH₃)₂C(CH₂OH)₂
C₅H₁₂O₂
104.15 g/mol
| Feature | Description |
|---|---|
| Functional Groups | Two primary hydroxyl groups (-OH) |
| Neopentyl Structure | Central carbon with two methyl and two hydroxymethyl groups |
| Symmetry | Symmetrical molecule |
| Reactivity | Primary alcohol reactivity (esterification, etherification) |
| Hydrogen Bonding | Strong (due to two hydroxyl groups) |
| Solubility | Soluble in water and many organic solvents |
| Property | Value |
|---|---|
| Appearance | White crystalline solid |
| Odor | Practically odorless |
| Molecular Formula | C₅H₁₂O₂ |
| Molecular Weight | 104.15 g/mol |
| Density (20°C) | 1.06 g/cm³ |
| Melting Point | ~128 °C |
| Boiling Point | ~210 °C (decomposes) |
| Flash Point | ~107 °C (closed cup) |
| Autoignition Temperature | ~360 °C |
| Vapor Pressure (20°C) | < 0.01 mmHg |
| Water Solubility (20°C) | Soluble (~830 g/L) |
| Solubility in Ethanol | Soluble |
| Solubility in Acetone | Soluble |
| Solubility in Methanol | Soluble |
| Solubility in Toluene | Soluble |
| Solubility in Ether | Soluble |
| pH (aqueous solution) | ~6.5 – 7.5 (neutral) |
| Hygroscopicity | Moderately hygroscopic |
| Heat of Fusion | ~25 kJ/mol |
| Thermal Stability | Stable; decomposes above 210°C |
| Solvent | Solubility | Conditions |
|---|---|---|
| Water | Soluble (~830 g/L) | 20°C |
| Ethanol | Soluble | 25°C |
| Methanol | Soluble | 25°C |
| Acetone | Soluble | 25°C |
| Toluene | Soluble | 25°C |
| Ether | Soluble | 25°C |
| Benzene | Soluble | 25°C |
| Hexane | Slightly soluble | 25°C |
| Property | Description |
|---|---|
| Chemical Character | Weakly acidic (due to primary hydroxyl groups) |
| Stability | Stable under normal storage conditions; good thermal stability |
| Reactivity | Reacts with acids to form esters; with isocyanates to form polyurethanes |
| Esterification | Forms esters with carboxylic acids (polyester resins) |
| Oxidation Resistance | High resistance to oxidation due to neopentyl structure |
| Hydrolysis Resistance | Good resistance to hydrolysis |
| Thermal Stability | High thermal stability; decomposes above 210°C |
| Incompatible Materials | Strong oxidizers, strong acids, strong bases |
NPG + R-COOH → NPG Ester + H₂O
NPG + Dicarboxylic Acid → Polyester + H₂O
NPG + 2 R-NCO → Polyurethane + CO₂
NPG + [O] → Oxidation Products + CO₂ + H₂O
Neopentyl Glycol is produced industrially by the aldol condensation of isobutyraldehyde with formaldehyde, followed by hydrogenation.
| Stage | Process | Description |
|---|---|---|
| 1 | Aldol Condensation | Isobutyraldehyde is reacted with formaldehyde in the presence of a base catalyst to form hydroxypivalaldehyde. |
| 2 | Hydrogenation | Hydroxypivalaldehyde is hydrogenated in the presence of a catalyst (e.g., nickel or copper chromite) to produce neopentyl glycol. |
| 3 | Purification | The crude product is purified by distillation or crystallization. |
| 4 | Drying | The purified product is dried to remove residual moisture. |
| 5 | Flaking/Packaging | The dried product is flaked or ground and packaged. |
Overall Reaction:
Isobutyraldehyde + 2 Formaldehyde → Hydroxypivalaldehyde → NPG + H₂O
| Application | Function |
|---|---|
| Unsaturated Polyester Resins (UPR) | Diol monomer; provides thermal stability and chemical resistance |
| Saturated Polyester Resins | Diol monomer; provides excellent weatherability and durability |
| Alkyd Resins | Diol component; provides hardness, gloss, and adhesion |
| Waterborne Polyester Resins | Diol monomer for eco-friendly coatings |
| Application | Function |
|---|---|
| Powder Coatings | Provides excellent weatherability and chemical resistance |
| Coil Coatings | Provides flexibility and adhesion |
| Automotive Coatings | Provides high gloss and durability |
| Industrial Coatings | Provides chemical resistance and thermal stability |
| Marine Coatings | Provides corrosion resistance |
| Application | Function |
|---|---|
| Polyester Plasticizers | Provides low volatility and good compatibility |
| Synthetic Lubricants | Provides thermal stability and oxidation resistance |
| Application | Function |
|---|---|
| Polyurethanes | Chain extender; provides flexibility and hydrolysis resistance |
| Epoxy Resins | Modifier; provides toughness and chemical resistance |
| Synthetic Lubricants | Base stock for high-performance lubricants |
| Application | Function |
|---|---|
| Adhesives | Provides adhesion and durability |
| Printing Inks | Provides solvent resistance and adhesion |
| Textile Auxiliaries | Provides softness and flexibility |
| Surfactants | Intermediate for specialty surfactants |
| Advantage | Description |
|---|---|
| Thermal Stability | Neopentyl structure provides excellent thermal stability (decomposition > 210°C). |
| Oxidation Resistance | No hydrogen atoms on the central carbon; excellent resistance to oxidation. |
| Chemical Resistance | Provides excellent resistance to acids, bases, and solvents. |
| Weathering Resistance | Provides excellent UV and weathering resistance in coatings. |
| Low Volatility | Low vapor pressure; reduces emissions during processing. |
| Hydrolysis Resistance | Good resistance to hydrolysis in polyester applications. |
| Gloss and Hardness | Provides high gloss and hardness in coating applications. |
| Property | NPG | Ethylene Glycol (MEG) | Propylene Glycol (PG) | 1,4-Butanediol (BDO) |
|---|---|---|---|---|
| Molecular Weight | 104.15 | 62.07 | 76.10 | 90.12 |
| Melting Point | 128°C | -13°C | -59°C | 20°C |
| Thermal Stability | Excellent | Moderate | Good | Moderate |
| Oxidation Resistance | Excellent | Poor | Moderate | Moderate |
| Water Solubility | Soluble | Miscible | Miscible | Miscible |
| Main Application | Polyester resins | Antifreeze | Humectant | Polyurethanes |
| Toxicity | Low | Toxic (MEG) | Low | Low |
| Parameter | Value |
|---|---|
| Acute Oral Toxicity (LD50, Rat) | ~ 3,500 – 5,000 mg/kg (low toxicity) |
| Acute Dermal Toxicity (LD50, Rabbit) | > 2,000 mg/kg |
| Acute Inhalation Toxicity | Low risk; dust may cause respiratory irritation |
| Skin Irritation | Mild irritant |
| Eye Irritation | Mild irritant |
| Skin Sensitization | Not a sensitizer |
| Mutagenicity | Negative |
| Carcinogenicity | Not classified as a carcinogen |
| Reproductive Toxicity | Not classified as a reproductive toxin |
| Target Organs | No specific target organs identified |
| Hazard Class | Category | H-Statement |
|---|---|---|
| Skin Irritation | Category 2 | H315 |
| Eye Irritation | Category 2 | H319 |
| Specific Target Organ Toxicity - SE | Category 3 | H335 |
Signal Word: WARNING
Hazard Pictograms: GHS07 (Exclamation Mark)
Hazard Statements (H-Codes):
| Code | Statement |
|---|---|
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
| H335 | May cause respiratory irritation. |
| Code | Statement |
|---|---|
| P261 | Avoid breathing dust. |
| P264 | Wash hands thoroughly after handling. |
| P271 | Use only outdoors or in a well-ventilated area. |
| P280 | Wear protective gloves/protective clothing/eye protection/face protection. |
| P302+P352 | IF ON SKIN: Wash with plenty of soap and water. |
| P305+P351+P338 | IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present. |
| P337+P313 | If eye irritation persists: Get medical advice/attention. |
| P501 | Dispose of contents/container in accordance with local regulations. |
| Route of Exposure | Action to Be Taken |
|---|---|
| Inhalation | Move to fresh air. If respiratory irritation persists, seek medical attention. |
| Skin Contact | Wash with plenty of soap and water. Remove contaminated clothing. If irritation persists, consult a physician. |
| Eye Contact | Rinse thoroughly with plenty of water for at least 15 minutes. Remove contact lenses. If irritation persists, seek medical attention. |
| Ingestion | Rinse mouth with water. Drink plenty of water. Do not induce vomiting. If large amount is swallowed, seek medical attention. |
| Parameter | Information |
|---|---|
| Fire Hazard | Combustible organic solid; may burn at high temperatures. |
| Hazards During Fire | Thermal decomposition produces toxic fumes including carbon monoxide and carbon dioxide. |
| Suitable Extinguishing Media | Water spray, CO₂, dry chemical powder, alcohol-resistant foam. |
| Special Protective Equipment | Self-contained breathing apparatus (SCBA), full protective clothing. |
| Parameter | Information |
|---|---|
| Personal Protection | Dust mask, protective goggles, gloves, coverall. |
| Ventilation | Increase ventilation; use local exhaust in confined spaces. |
| Containment | Cover spilled area to prevent dust dispersion. |
| Cleaning Methods | Collect dry using vacuum or careful sweeping. Avoid washing with water (soluble). |
| Environmental Precautions | Prevent entry into drains, sewers, and water bodies. |
| Waste Disposal | Dispose of in accordance with local regulations. |
| Parameter | Information |
|---|---|
| Storage Conditions | Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). |
| Container Requirements | Keep tightly closed in original packaging. Protect from moisture. |
| Materials to Avoid | Strong oxidizers, strong acids, strong bases. |
| Shelf Life | 24 months (under proper storage conditions). |
| Stability Note | Hygroscopic; protect from moisture to prevent caking. |
| Packaging Options | 25 kg bags, 500 kg big-bags, 1000 kg palletized. |
| Packaging Type | Quantity | Material |
|---|---|---|
| Kraft Bag + PE Liner | 25 kg | Paper / Polyethylene |
| Plastic Drum | 25 kg | HDPE |
| Fiber Drum | 25 kg | Cardboard / Plastic |
| Big-Bag | 500 – 1000 kg | Polypropylene |
| Parameter | Information |
|---|---|
| UN Number | Not applicable (not classified as dangerous goods) |
| Hazard Class | Not classified as hazardous for transport |
| Packing Group | Not applicable |
| ADR/RID | Not regulated |
| IMDG Code | Not regulated |
| IATA (Air) | Not regulated |
| Marine Pollutant | No |
| Transport Temperature | Ambient temperature; protect from moisture. |
| Region / Authority | Status |
|---|---|
| European Union (REACH) | Registered; industrial chemical. |
| USA (TSCA) | Listed. |
| Turkey (KKDIK) | Registered under chemical registration regulations. |
| EINECS | 204-781-0 |
| Name | Context |
|---|---|
| Neopentyl Glycol | Common name |
| NPG | Abbreviation |
| 2,2-Dimethylpropane-1,3-diol | IUPAC name |
| 2,2-Dimethyl-1,3-propanediol | Chemical name |
| Dimethylolpropane | Historical name |
| CAS | 126-30-7 |
| EC | 204-781-0 |
| Property | Value |
|---|---|
| CAS Number | 126-30-7 |
| EC Number | 204-781-0 |
| Molecular Formula | C₅H₁₂O₂ |
| Molecular Weight | 104.15 g/mol |
| Appearance | White crystalline solid |
| Odor | Practically odorless |
| Density (20°C) | 1.06 g/cm³ |
| Melting Point | ~128 °C |
| Boiling Point | ~210 °C (decomposes) |
| Water Solubility (20°C) | Soluble (~830 g/L) |
| Primary Uses | Polyester resins, coatings, plasticizers, lubricants |
| Shelf Life | 24 months |
| UN Number | Not applicable |
| GHS Signal Word | WARNING |
CRITICAL NOTICES:
Hygroscopic Nature: NPG is moderately hygroscopic and absorbs moisture from the air. Store in tightly sealed containers to prevent moisture absorption and caking.
Thermal Stability: NPG has excellent thermal stability but decomposes above 210°C. Avoid excessive heating during processing.
Dust Explosion Risk: Fine NPG dust may form explosive mixtures with air. Use dust control measures and avoid ignition sources.
Incompatibility: NPG is incompatible with strong oxidizers, strong acids, and strong bases. Reaction with these materials may cause fire or toxic gas release.
Low Toxicity: NPG has low acute toxicity but may cause mild skin and eye irritation. Use appropriate personal protective equipment.
Quality Grades: NPG is available in various grades (standard, flake, powder). Select the appropriate grade for your application.
Excellent Weatherability: NPG-based polyester resins provide excellent weatherability, UV resistance, and gloss retention, making them ideal for outdoor coatings.
NPG vs. Other Glycols: The neopentyl structure provides superior thermal stability and oxidation resistance compared to other glycols (e.g., ethylene glycol, propylene glycol).
BEST PRACTICE RECOMMENDATIONS:
Storage: Store in a cool, dry, and well-ventilated area. Keep containers tightly closed. Protect from moisture.
Handling: Use protective gloves, goggles, and dust mask. Avoid dust formation. Ensure adequate ventilation.
Processing: In polyester resin production, use appropriate catalysts and reaction conditions. Monitor temperature to prevent decomposition.
Quality Control: Test for purity, water content, and melting point. Ensure product meets specifications.
Waste Management: Dispose of waste in accordance with local regulations. Incineration is recommended for contaminated materials.
LEGAL DISCLAIMER:
This Technical Data Sheet (TDS) is for informational purposes only and is prepared based on available technical data. The user is solely responsible for determining the suitability of the product for their specific application and for complying with all local, national, and international regulations. For complete safety, storage, handling, transport, waste, and regulatory compliance information, the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier must be consulted. This document does not substitute professional advice.