DIMETHYLPROPANEDIOL

Dimethylpropanediol is a white crystalline polyol in which two hydroxyl groups are bonded to a sterically hindered quaternary carbon center, giving it exceptional resistance to oxidation, hydrolysis, and thermal degradation compared to conventional glycols.
Dimethylpropanediol has a melting point of approximately 128–131 °C, is readily soluble in water and many organic solvents, and serves as a versatile industrial intermediate.
Dimethylpropanediol is widely used in the production of polyester and alkyd resins, synthetic lubricants, plasticizers, stabilizers, and specialty coatings, where it enhances hardness, weatherability, and chemical durability.

CAS Number: 126-30-7
EC Number: 204-781-0
Molecular Formula: C₅H₁₂O₂
Molecular Weight: 104.15 g/mol

Synonyms: 126-30-7, 2,2-DIMETHYL-1,3-PROPANEDIOL, 2,2-Dimethylpropane-1,3-diol, 1,3-Propanediol, 2,2-dimethyl-, Dimethylolpropane, Neopentanediol, Neopentylglycol, NPG Glycol, Hydroxypivalyl alcohol, 2,2-Dimethyltrimethylene glycol, Nexcoat 600, NSC 55836, CCRIS 3273, 2,2-Dimethyl-1,3 propanediol, UNII-QI80HXD6S5, EINECS 204-781-0, BRN 0605291, DTXSID8027036, ORISTAR NPG, AI3-05739, NSC-6366, 1,3-Dihydroxy-2,2-dimethylpropane, NSC-55836, NEOPENTYL GLYCOL [MI], NEOPENTYLGLYCOL ECAILLES, DTXCID007036, HSDB 8424, CHEBI:143768, EC 204-781-0, 4-01-00-02551 (Beilstein Handbook Reference), 2,2-Dimethyl-1,3-dihydroxypropane, DIMETHYL-1,3-PROPANEDIOL, 2,2-, Dimetilolpropano, Neopentylglykol, Neopentilglicole, Neopentilene glicole, 2,2Dimethylolpropan, 2,2Dimetil1,3propandiolo, 2,2Dimethyl1,3propanediol, 2,2Dimethylpropane1,3diol, 2,2Dimethyltrimethylene glycol, 1,3Propanediol, 2,2dimethyl, 1,3Dihydroxy2,2dimethylpropane, 2,2Dimethyl1,3dihydroxypropane, NEOPENTYL GLYCOL [INCI], Propanediol, 2,2dimethyl, 1,3, 1,3-PROPANEDIOL, 2,2-DIMETHYL, 204-781-0, inchi=1/c5h12o2/c1-5(2,3-6)4-7/h6-7h,3-4h2,1-2h, pentaglycol, slcvbvwxlsekpl-uhfffaoysa-n, Neopentylene glycol, Neol, Dimethyltrimethylene glycol, QI80HXD6S5, 2,2-dimethyl-1,3-propandiol, 2,3 propanediol, WLN: Q1X1 & 1 & 1Q, CAS-126-30-7, MFCD00004685, Propanediol, 2,2-dimethyl-, 1,3-, 2,2-Bis(hydroxymethyl)propane, 2,2-dimethylolpropane, SCHEMBL19621, CBDivE_004836, 2,2-dimethylpropan-1,3-diol, 2,2-dimethyl 1,3-propanediol, 2.2-dimethyl-1,3-propanediol, 2,3-Dimethyl-1,3-propanediol, CHEMBL3184801, 2,2-dimethyl -1,3-propanediol, 2,2-dimethyl-1,3-propane diol, 2,2-dimethyl-propane-1,3-diol, NSC6366, NSC55836, 2,2-Dihydroxy-2,2-dimethylpropane, Tox21_201363, Tox21_303298, AKOS005068060, CS-W011300, FD54856, 2,2-Dimethyl-1,3-propanediol, 99%, NCGC00249034-01, NCGC00256980-01, NCGC00258915-01, AS-13611, D0791, NS00003307, EN300-30502, D71071, Q413855, F0001-0385, 77498-68-1

Dimethylpropanediol is a white crystalline polyol characterized by two hydroxyl groups attached to a quaternary carbon center, giving it high steric hindrance and excellent chemical stability. 
This structural feature makes Dimethylpropanediol resistant to oxidation, hydrolysis, and thermal degradation, distinguishing it from conventional glycols.

Dimethylpropanediol is readily soluble in water and many organic solvents, with a melting point around 128–131 °C, and is widely used as a key intermediate in the production of polyester resins, alkyd resins, plasticizers, synthetic lubricants, stabilizers, and coatings.
In polymer chemistry, Dimethylpropanediol enhances weatherability, hardness, and chemical resistance, making it valuable in applications ranging from paints and powder coatings to automotive parts and construction materials.

Dimethylpropanediol is an organic chemical compound.
Dimethylpropanediol is used in the synthesis of polyesters, paints, lubricants, and plasticizers.

When used in the manufacture of polyesters, Dimethylpropanediol enhances the stability of the product towards heat, light, and water.
By esterification reaction with fatty or carboxylic acids, synthetic lubricating esters with reduced potential for oxidation or hydrolysis, compared to natural esters, can be produced.

Dimethylpropanediol is a crystalline solid.
Dimethylpropanediol has a sweetish odor.

Dimethylpropanediol is very soluble in water.
Dimethylpropanediol is the main glycol in powder polyester formulations.

These polyesters are used, for example, in the automotive, domestic appliance, and general industries.
Dimethylpropanediol is also widely used in solvent borne polyester paints for coil coatings, cans, automotive paints, aerospace and transportation applications, and for other stoving enamels.

The aldol addition of isobutyraldehyde (2-methylpropanal) and formaldehyde gives hydroxypivaldehyde (3-hydroxy-2,2- dimethylpropanal), which is then reduced to Dimethylpropanediol.
Both aldol addition and subsequent reduction are exothermic.

Hydroxypivaldehyde can be reduced either by a crossed Cannizzaro reaction with equimolar amounts of formaldehyde and a base, or by catalytic hydrogenation.
Impurities may include Dimethylpropanediol monoformate, Dimethylpropanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol, and the cyclic acetal from the reaction of hydroxypivaldehyde and Dimethylpropanediol.

Dimethylpropanediol is a white crystalline polyol distinguished by its unique structure in which two hydroxyl groups are bonded to a sterically hindered quaternary carbon atom.
This structural configuration imparts exceptional stability against oxidation, hydrolysis, and thermal degradation, making Dimethylpropanediol superior to conventional glycols in terms of durability.

With a melting point of approximately 128–131 °C, Dimethylpropanediol is moderately hygroscopic and readily soluble in water as well as many organic solvents.
Industrially, Dimethylpropanediol is a highly versatile intermediate, widely employed in the synthesis of polyester and alkyd resins that provide enhanced hardness, weather resistance, and chemical durability.

These resins are fundamental in the production of coatings, paints, varnishes, adhesives, and construction materials, where long-term resistance to moisture, light, and environmental stress is critical.
Additionally, Dimethylpropanediol serves as a key building block in the manufacture of synthetic lubricants, plasticizers, stabilizers, and specialty esters, which are valued for their high thermal stability and low volatility in demanding applications such as automotive, aerospace, and industrial machinery. 

Beyond coatings and lubricants, Dimethylpropanediol finds use as an intermediate in pharmaceuticals and fine chemicals, reflecting its broad utility.
Owing to Dimethylpropanediol's chemical robustness and performance-enhancing qualities, Dimethylpropanediol has become an indispensable raw material in modern polymer and materials chemistry.

Market Overview of Dimethylpropanediol:
Dimethylpropanediol occupies a crucial position in the global specialty chemicals and resins market, driven by its unique chemical stability and performance-enhancing properties.
The demand for Dimethylpropanediol is primarily fueled by the construction, automotive, coatings, and industrial manufacturing sectors, where it is used extensively in the production of polyester resins, alkyd resins, and powder coatings.
These applications benefit from Dimethylpropanediol’s ability to impart excellent weather resistance, gloss retention, and durability to end products, making it indispensable in high-performance surface treatments.

Globally, the market has shown steady growth, with Asia-Pacific (China, India, and Southeast Asia) emerging as the largest consumer and production hub, due to rapid industrialization, booming infrastructure projects, and expansion in the automotive industry.
Europe and North America remain significant markets, focusing on environmentally friendly, high-quality resins and coatings.
Powder coatings, in particular, are gaining traction because of their low environmental impact and superior performance, further driving Dimethylpropanediol demand.

On the supply side, major chemical manufacturers such as BASF, Eastman Chemical Company, LG Chem, Mitsubishi Gas Chemical, and OXEA are key players, with investments in capacity expansions and sustainability initiatives to meet rising global consumption.
With increasing regulatory pressure on VOC emissions and growing consumer demand for durable and eco-friendly materials, the Dimethylpropanediol market is expected to maintain strong growth in the coming decade.

Uses of Dimethylpropanediol:
Dimethylpropanediol is a versatile chemical intermediate with wide-ranging industrial applications.
Dimethylpropanediol's most significant use is in the production of polyester and alkyd resins, which are essential in paints, coatings, adhesives, and varnishes, where Dimethylpropanediol enhances weather resistance, hardness, and gloss retention.

In powder coatings, Dimethylpropanediol plays a vital role in improving durability, UV resistance, and hydrolytic stability, making it a preferred material for automotive finishes, industrial equipment, and construction materials.
Beyond resins, Dimethylpropanediol is a key component in synthetic lubricants and specialty esters, providing excellent thermal stability, oxidation resistance, and low volatility, which are particularly valuable in high-performance machinery, aviation, and automotive systems.

Dimethylpropanediol is also used in plasticizers and stabilizers, especially in PVC formulations, where it improves flexibility and prevents degradation under heat and light.
Additionally, Dimethylpropanediol is employed in adhesives and sealants, where its crosslinking ability enhances strength, chemical resistance, and longevity in structural and protective applications.

In the pharmaceutical and fine chemical industries, Dimethylpropanediol serves as an intermediate for drug synthesis and specialty compounds, while its derivatives also find use in insulation materials, specialty polymers, and environmentally friendly low-VOC coating systems.
Thanks to its stability and performance-enhancing properties, Dimethylpropanediol has become an indispensable raw material across diverse industrial sectors.

Resins and Coatings:
Dimethylpropanediol is a major raw material in the manufacture of polyester resins and alkyd resins, which are widely used in paints, varnishes, adhesives, and surface coatings.
In powder coatings, Dimethylpropanediol enhances durability, weather resistance, and gloss retention, making it ideal for automotive, industrial, and construction applications.
Dimethylpropanediol-based polyesters provide superior UV resistance, hydrolytic stability, and hardness, which are critical for exterior coatings.

Plasticizers and Stabilizers:
Dimethylpropanediol derivatives are used as plasticizers that improve flexibility and workability of plastics.
Dimethylpropanediol also serves as a component in PVC stabilizers, helping to prevent degradation under heat and light exposure.

Synthetic Lubricants and Oils:
Dimethylpropanediol esters are formulated into synthetic lubricants with excellent thermal stability, oxidation resistance, and low volatility.
Such lubricants are particularly valuable in high-temperature machinery, aviation engines, and automotive systems.

Adhesives and Sealants:
As a crosslinking agent, Dimethylpropanediol contributes to the strength, chemical resistance, and longevity of adhesives and sealants.
Frequently used in industrial bonding, construction joints, and protective sealants.

Pharmaceuticals and Fine Chemicals:
Dimethylpropanediol functions as an intermediate in the synthesis of pharmaceuticals, agrochemicals, and specialty fine chemicals.
Dimethylpropanediol's stable diol structure allows selective derivatization for advanced chemical formulations.

Specialty Applications:
Dimethylpropanediol is used in the production of plastic optical lenses, insulation materials, and specialty polymers.
Plays a role in environmentally friendly, low-VOC coating systems, aligning with sustainability trends.

Benefits of Dimethylpropanediol:
Dimethylpropanediol offers several advantages that make it a preferred raw material in modern industrial chemistry.
Dimethylpropanediol's unique molecular structure, with two hydroxyl groups attached to a sterically hindered quaternary carbon, provides exceptional stability against oxidation, hydrolysis, and thermal degradation, ensuring long-lasting performance in harsh environments.

In coatings and resins, Dimethylpropanediol imparts superior weather resistance, UV stability, hardness, and gloss retention, which significantly extend the service life of paints, varnishes, and powder coatings.
Dimethylpropanediol's use in synthetic lubricants and esters delivers high thermal stability, low volatility, and excellent lubricating properties, making it ideal for demanding applications in automotive, aerospace, and industrial machinery.

Dimethylpropanediol also contributes to low-VOC and environmentally friendly coating systems, aligning with global sustainability and regulatory trends.
Furthermore, Dimethylpropanediol's role in adhesives, sealants, and plastics improves mechanical strength, flexibility, and chemical resistance, enhancing the overall durability of end products.
These combined benefits make Dimethylpropanediol an essential chemical building block that not only improves material performance but also supports innovation in eco-friendly and high-performance industrial solutions.

Production of Dimethylpropanediol:
Dimethylpropanediol is produced industrially through well-established chemical processes that utilize formaldehyde and isobutyraldehyde as the primary raw materials.
In the most common synthesis route, isobutyraldehyde undergoes an aldol condensation reaction with formaldehyde, yielding hydroxypivaldehyde as the intermediate.

This intermediate is then subjected to catalytic hydrogenation, typically using a metal catalyst such as copper, nickel, or palladium, under elevated temperature and pressure, to produce Dimethylpropanediol in high yield and purity.
The reaction pathway is designed to maximize selectivity, as the steric hindrance around the quaternary carbon atom provides enhanced stability to the diol product.

After hydrogenation, the crude Dimethylpropanediol is purified through crystallization or distillation to remove residual by-products and ensure the desired physical properties.
In large-scale production, continuous processes are favored to improve efficiency, reduce waste, and maintain consistent product quality.

Modern plants also integrate energy recovery and recycling systems to enhance sustainability and reduce environmental impact.
With growing demand in coatings, resins, and lubricants, global manufacturers have invested in capacity expansions and process optimizations, ensuring that Dimethylpropanediol remains an accessible and cost-effective raw material for the specialty chemicals industry.

Synthesis of Dimethylpropanediol:

The industrial synthesis of Dimethylpropanediol is carried out via a two-step process starting from isobutyraldehyde (IBA) and formaldehyde (HCHO):

Aldol Condensation:
In the first step, isobutyraldehyde reacts with two equivalents of formaldehyde in the presence of a basic catalyst (often sodium hydroxide, calcium hydroxide, or amines).
This leads to the formation of hydroxypivaldehyde (HPA; 3-hydroxy-2,2-dimethylpropanal) via an aldol addition reaction.

Catalytic Hydrogenation:
Hydroxypivaldehyde is then hydrogenated under elevated pressure (100–200 bar) and temperature (80–130 °C) in the presence of a metal catalyst such as copper chromite, Raney nickel, or palladium.
This reduces the aldehyde functional group to a hydroxyl group, producing Dimethylpropanediol (2,2-dimethyl-1,3-propane diol).

Purification:
The crude Dimethylpropanediol product is purified via crystallization or vacuum distillation to remove residual aldehydes, catalyst residues, and water.
The final material is obtained as a white crystalline solid with a high purity suitable for resin, lubricant, and plasticizer production.

Reactions of Dimethylpropanediol:
Dimethylpropanediol is synthesized industrially by the aldol reaction of formaldehyde and isobutyraldehyde.
This creates the intermediate hydroxypivaldehyde, which can be converted to Dimethylpropanediol with either excess formaldehyde or by palladium on carbon hydrogenation.
Dimethylpropanediol is used as a protecting group for ketones, for example in gestodene synthesis.

A condensation reaction of Dimethylpropanediol with 2,6-di-tert-butylphenol gives CGP-7930.
Organoboronic acid esters of Dimethylpropanediol are useful in the Suzuki reaction.

History of Dimethylpropanediol:
Dimethylpropanediol was first developed in the mid-20th century, during a period of rapid innovation in polyol and resin chemistry, when the coatings and plastics industries sought more stable and durable intermediates than conventional glycols could provide.
Early research in the 1930s–1940s demonstrated that incorporating a sterically hindered quaternary carbon atom adjacent to hydroxyl groups could significantly improve resistance to oxidation, hydrolysis, and thermal degradation.

This discovery led to the industrial synthesis of Dimethylpropanediol via the hydroxypivaldehyde route, which quickly gained prominence for its efficiency and scalability.
By the 1950s, large-scale commercial production was established, particularly in Europe and North America, as demand for alkyd resins, polyester resins, and synthetic lubricants surged in construction, automotive, and industrial markets.

Companies such as BASF, Eastman Chemical, and Mitsubishi Gas Chemical played pivotal roles in scaling production and standardizing Dimethylpropanediol as a key raw material in the global chemicals trade.
Over the decades, Dimethylpropanediol became integral to the development of powder coatings and low-VOC systems, aligning with growing environmental and regulatory pressures from the late 20th century onward.
Today, Dimethylpropanediol is regarded as one of the most important diols in specialty chemicals, with its history reflecting both the advancement of modern polymer science and the industrial shift toward more durable and sustainable chemical building blocks.

Handling and Storage of Dimethylpropanediol:

Handling:
Avoid generating dust.
Do not breathe dust or vapors.

Avoid contact with eyes, skin, and clothing.
Use only in well-ventilated areas.
Wash thoroughly after handling.

Storage:
Store in a tightly closed container in a cool, dry, and well-ventilated area.
Protect from moisture, direct sunlight, and incompatible materials (strong oxidizing agents, strong acids).
Keep away from heat and ignition sources.

Stability and Reactivity of Dimethylpropanediol:

Stability:
Stable under normal ambient conditions of temperature and pressure.

Reactivity:
Reacts with strong oxidizing agents, producing heat and potentially hazardous decomposition products.

Hazardous Decomposition Products:
Thermal decomposition may release carbon monoxide, carbon dioxide, and other toxic fumes.

Polymerization:
Not known to undergo hazardous polymerization.

First Aid Measures of Dimethylpropanediol:

Inhalation:
Move person to fresh air.
If breathing is difficult, administer oxygen and seek medical attention.

Skin Contact:
Wash immediately with soap and plenty of water.
Remove contaminated clothing.
Seek medical advice if irritation develops.

Eye Contact:
Rinse cautiously with water for at least 15 minutes, lifting eyelids occasionally.
Remove contact lenses if present.
Seek medical attention if irritation persists.

Ingestion:
Rinse mouth with water.
Do NOT induce vomiting unless directed by medical personnel.
Seek immediate medical attention.

Firefighting Measures of Dimethylpropanediol:

Suitable Extinguishing Media:
Use water spray, alcohol-resistant foam, dry chemical, or carbon dioxide.

Unsuitable Media:
Do not use water jet directly, as Dimethylpropanediol may spread the material.

Fire Hazards:
Combustible solid.
Dust can form explosive mixtures with air in confined spaces.

Protective Equipment for Firefighters:
Wear self-contained breathing apparatus (SCBA) and full protective gear.
Cool containers exposed to fire with water spray.

Accidental Release Measures of Dimethylpropanediol:

Personal Precautions:
Avoid dust formation.
Use personal protective equipment.
Provide adequate ventilation.

Environmental Precautions:
Prevent entry into sewers, waterways, or confined areas.

Cleanup Methods:
Sweep up or vacuum without generating dust.
Collect in suitable, labeled containers for disposal.

Wash spill area with water after removal.
Dispose of waste according to local regulations.

Exposure Controls / Personal Protective Equipment of Dimethylpropanediol:

Engineering Controls:
Use process enclosures, local exhaust ventilation, or other engineering controls to maintain airborne levels below recommended limits.

Eye/Face Protection:
Safety goggles with side shields or face shield.

Skin Protection:
Protective gloves (nitrile, neoprene) and protective clothing to prevent skin contact.

Respiratory Protection:
Use NIOSH-approved respirators if dust exposure exceeds permissible limits.

Hygiene Measures:
Wash hands, forearms, and face thoroughly after handling.
Do not eat, drink, or smoke in work areas.
Remove contaminated clothing and wash before reuse.

Identifiers of Dimethylpropanediol:
Chemical Name: Dimethylpropanediol
IUPAC Name: 2,2-Dimethyl-1,3-propane diol
Common Abbreviations: NPG
CAS Number: 126-30-7
EC (EINECS) Number: 204-781-0
UN Number: Not classified as dangerous for transport
Molecular Formula: C₅H₁₂O₂
Molecular Weight: 104.15 g/mol
InChI: InChI=1S/C5H12O2/c1-5(2,3)4(6)7/h4,6-7H,1-3H3
InChI Key: TUHBPFPOKJPKCG-UHFFFAOYSA-N
SMILES Notation: CC(C)(C)C(CO)O
HS Code (Customs): 290539 – Polyhydric alcohols, nes

CAS Number: 126-30-7
EC (EINECS) Number: 204-781-0
RTECS Number: UY2450000
UN Number: Not regulated as hazardous for transport
HS Code (Customs): 290539 (Polyhydric alcohols, nes)
Molecular Formula: C₅H₁₂O₂
Molecular Weight: 104.15 g/mol
Structure Type: Aliphatic diol with quaternary carbon center
InChI: InChI=1S/C5H12O2/c1-5(2,3)4(6)7/h4,6-7H,1-3H3
InChI Key: TUHBPFPOKJPKCG-UHFFFAOYSA-N
SMILES Notation: CC(C)(C)C(CO)O
PubChem CID: 31246
ChemSpider ID: 28953
KEGG ID: C13929
UNII (FDA): 4WGP7U8XUS

Properties of Dimethylpropanediol:
Appearance: White crystalline solid (odorless)
Odor: Practically odorless
Physical State: Solid at room temperature
Taste: Slightly sweet (not for ingestion; toxicological risk)

Molecular Formula: C₅H₁₂O₂
Molecular Weight: 104.15 g/mol
Melting Point: 128–131 °C
Boiling Point: Decomposes before boiling (~210 °C under reduced pressure)
Flash Point: > 130 °C (closed cup)
Autoignition Temperature: ~395 °C
Density (at 20 °C): 1.06 g/cm³
Vapor Pressure (25 °C): Negligible (<0.01 mmHg)
Refractive Index: 1.456 (at 20 °C, liquid melt)
Viscosity (molten, 130 °C): ~30–40 mPa·s

Solubility:
Water: Freely soluble (miscible at room temperature)
Alcohols: Soluble (ethanol, methanol, isopropanol)
Ketones: Soluble (acetone, MEK)
Aromatic Hydrocarbons: Slightly soluble (toluene, xylene)
Aliphatic Hydrocarbons: Poor solubility

Partition Coefficient (log P, octanol/water): −0.14 (hydrophilic)
pKa (hydroxyl groups): ~15–16 (weakly acidic, typical alcohol)

Stability:
Stable under normal storage conditions.
Hygroscopic – absorbs moisture from air.
Resistant to oxidation and hydrolysis due to steric hindrance at central carbon.

Chemical Formula: C₅H₁₂O₂
Molecular Weight: 104.15 g/mol
Structural Formula: HO–CH₂–C(CH₃)₂–CH₂–OH
Functional Group: Primary aliphatic diol (sterically hindered)
Class: Polyhydric alcohol (polyol)

Appearance: White crystalline solid (fine crystals or flakes)
Odor: Practically odorless or faintly sweet
Taste: Slightly sweet (not for consumption; toxicological risk)
Melting Point: 128–131 °C
Boiling Point: Decomposes before boiling; reported ~210 °C at reduced pressure (~15 mmHg)
Flash Point: ~140 °C (closed cup)
Autoignition Temperature: ~395 °C
Density (20 °C): 1.06 g/cm³
Bulk Density: ~600–700 kg/m³ (depending on crystal form)
Heat of Fusion: ~180 J/g
Heat of Combustion: ~2,980 kJ/mol

Vapor Pressure (25 °C): Very low (<0.01 mmHg)
Specific Heat Capacity (25 °C): ~2.2 J/g·K
Viscosity (molten, 130 °C): 30–40 mPa·s
Refractive Index (n20): 1.456 (molten state)
Hygroscopicity: Moderate – absorbs moisture from air
Partition Coefficient (log Pow, octanol/water): −0.14 (hydrophilic nature)