Isooctanol

Product Details

CasNo： 104 - 76 - 7

MF： C₈H₁₈O

Appearance： liquid

Purity： 99.5%

1. Basic Information​

1.1 Chemical Name​

Isooctanol (also known as 2 - Ethylhexanol)​

1.2 Synonyms​

6 - Methyl - 1 - heptanol, 6 - Methylheptanol, Alcohol C8, Iso octan - 1 - ol​

1.3 Molecular Formula​

C₈H₁₈O​

1.4 Molecular Weight​

130.23 g/mol​

1.5 CAS Number​

104 - 76 - 7 (main isomer), 26952 - 21 - 6 (mixed isomers)​

1.6 EINECS Number​

248 - 133 - 5​

1.7 Molecular Structure​

CH₃(CH₂)₃CH(C₂H₅)CH₂OH​

2. Physical Properties​

2.1 Appearance​

Colorless to pale yellow oily liquid​

2.2 Odor​

Has a sweet and faint floral fragrance​

2.3 Density​

0.831 - 0.835 g/mL at 25 °C​

2.4 Melting Point​

−76 °C (lit.)​

2.5 Boiling Point​

185 - 189 °C (lit.)​

2.6 Flash Point​

77 °C (closed - cup)​

2.7 Solubility​

Slightly soluble in water (1 g dissolves in about 720 times of water), only 0.1% solubility in water at 20 °C. Miscible with most organic solvents such as alcohol, ether, and chloroform.​

2.8 Vapor Pressure​

0.13 kPa (20 °C)​

2.9 Vapor Density​

4.48 (relative to air = 1)​

2.10 Refractive Index​

n₂₀/D 1.4308 (lit.)​

3. Chemical Properties​

3.1 Reactivity​

• Esterification: As an alcohol, isooctanol can react with carboxylic acids in the presence of an acid catalyst to form esters. For example, reacting with phthalic anhydride to produce dioctyl phthalate (DOP), which is a widely used plasticizer:​

• C₈H₁₇OH + C₈H₄O₃ → C₂₄H₃₈O₄ (DOP) + H₂O​

• Oxidation: Can be oxidized to the corresponding aldehyde and then to the carboxylic acid. In the presence of appropriate oxidizing agents such as potassium permanganate or potassium dichromate in acidic solutions, the following reactions can occur:​

• First, oxidation to aldehyde: 3C₈H₁₇OH + 2K₂Cr₂O₇ + 8H₂SO₄ → 3C₈H₁₅CHO + 2Cr₂(SO₄)₃ + 2K₂SO₄ + 11H₂O​

• Then, further oxidation to carboxylic acid: 3C₈H₁₅CHO + K₂Cr₂O₇ + 4H₂SO₄ → 3C₈H₁₅COOH + Cr₂(SO₄)₃ + K₂SO₄ + 4H₂O​

• Combustion: Burns readily in air, producing carbon dioxide and water. The combustion reaction equation is: 2C₈H₁₈O + 25O₂ → 16CO₂ + 18H₂O​

3.2 Stability​

Stable under normal conditions. However, it is flammable and can form explosive mixtures with air within a certain concentration range (explosive limit: 0.9% - 7.1% by volume in air). It should be kept away from strong oxidizing agents, strong acids, and alkalis to avoid chemical reactions.​

4. Production Methods​

4.1 Propylene Hydroformylation (Oxo - Process)​

• Raw Materials and Reaction Process:​

• Propylene and synthesis gas (a mixture of carbon monoxide and hydrogen) are used as raw materials.​

• In the presence of a rhodium - based catalyst (such as rhodium - triphenylphosphine complex) or a cobalt - based catalyst, propylene reacts with synthesis gas to form a mixture of butyraldehydes (including n - butyraldehyde and isobutyraldehyde) through the hydroformylation reaction. The reaction conditions are usually at a temperature of about 100 - 180 °C and a pressure of several to tens of megapascals.​

• The reaction equation for the hydroformylation of propylene is: CH₃CH = CH₂+CO + H₂ → CH₃CH₂CH₂CHO (n - butyraldehyde)+(CH₃)₂CHCHO (isobutyraldehyde)​

• Then, the mixture of butyraldehydes is subjected to aldol condensation. In the case of producing isooctanol, n - butyraldehyde is mainly used. Two molecules of n - butyraldehyde undergo aldol condensation under basic conditions to form 2 - ethyl - 3 - hydroxyhexanal: 2CH₃CH₂CH₂CHO → CH₃CH₂CH₂CH(OH)CH(C₂H₅)CHO​

• Finally, the 2 - ethyl - 3 - hydroxyhexanal is hydrogenated in the presence of a nickel - based or copper - based hydrogenation catalyst at an appropriate temperature (such as 150 - 200 °C) and pressure (such as 1 - 5 MPa) to obtain isooctanol: CH₃CH₂CH₂CH(OH)CH(C₂H₅)CHO + H₂ → CH₃(CH₂)₃CH(C₂H₅)CH₂OH​

4.2 From Natural Oils and Fats (Less Common)​

• Some natural oils and fats contain esters of fatty acids with higher alcohols. Through hydrolysis and subsequent chemical reactions, isooctanol can be obtained. For example, by hydrolyzing certain triglycerides in vegetable oils, fatty acids and glycerol are obtained. Then, through a series of processes such as reduction and isomerization, isooctanol can be synthesized. However, this method is more complex and less commonly used in large - scale industrial production compared to the propylene hydroformylation method.​

5. Applications​

5.1 Plasticizer Industry​

• Main Plasticizer Production: Isooctanol is mainly used for the production of plasticizers. The most well - known is the production of dioctyl phthalate (DOP), which is one of the most widely used plasticizers in the polyvinyl chloride (PVC) industry. DOP can significantly improve the flexibility, processability, and durability of PVC products. In addition to DOP, isooctanol is also used to produce other plasticizers such as dioctyl adipate (DOA), which has good low - temperature flexibility and is often used in applications where low - temperature performance is required, and trioctyl trimellitate (TOTM), which has excellent heat resistance and is suitable for high - temperature - resistant PVC products.​

• The reaction equations for the synthesis of these plasticizers are as follows:​

• For DOP: 2C₈H₁₇OH + C₈H₄O₃ → C₂₄H₃₈O₄ (DOP) + H₂O​

• For DOA: 2C₈H₁₇OH + C₆H₁₀O₄ → C₂₂H₄₂O₄ (DOA) + H₂O​

• For TOTM: 3C₈H₁₇OH + C₉H₄O₆ → C₃₃H₅₄O₆ (TOTM) + 3H₂O​

• Consumption in PVC: The consumption of isooctanol in the production of PVC plasticizers accounts for about 95% of the total consumption of PVC. PVC products with plasticizers added can be used in a wide range of applications, such as pipes, cables, films, and plastic products in daily life.​

5.2 Solvent Applications​

• In the Coating and Ink Industry: Isooctanol serves as an excellent solvent. In the coating industry, it can dissolve various resins, pigments, and additives, ensuring good flowability and leveling of the coating during application, and helping to form a smooth and uniform film. In the ink industry, it can dissolve colorants and binders, making the ink have good transfer performance during the printing process, which is beneficial to obtaining clear and vivid prints.​

• In the Resin and Plastic Industry: It can be used as a solvent for some resins and plastics during processing. For example, it can be used in the production of certain adhesives to dissolve polymer components, improving the adhesion and workability of the adhesives. It can also be used in the preparation of some polymer solutions for specific processing needs.​

5.3 Perfume and Flavor Industry​

• As a Fragrance Ingredient: Isooctanol has a certain sweet and floral odor, so it can be used as a fragrance ingredient. It can be used to blend floral fragrances such as rose and lily, and is also used in soap - based fragrances to add a pleasant scent.​

• In the Food Industry: It is an approved food flavor. It is often used in the formulation of flavors for baked goods, frozen dairy products, and puddings. It can add a unique flavor note to these food products, enhancing their overall flavor profile.​

5.4 Other Applications​

• Antifoaming Agent: It can be used as an antifoaming agent in industries such as latex production, paper making, and some chemical processes. In latex production, it can effectively reduce the formation of foam, ensuring the stability and quality of the latex product. In paper making, it can prevent the formation of foam in the pulp suspension, which is beneficial to the paper - making process.​

• Dispersant and Lubricant: Isooctanol can act as a dispersant to help disperse solid particles evenly in a liquid medium. For example, in the production of some pigments or fillers, it can be used to improve the dispersion of these particles, preventing agglomeration. It can also be used as a lubricant in some applications, reducing friction between moving parts.​

• Intermediate in Organic Synthesis: It is used as an intermediate in the synthesis of many organic compounds. For example, in the production of some surfactants, isooctanol can react with other substances to form non - ionic or anionic surfactants. In the pharmaceutical industry, it may be used in the synthesis of certain drugs or pharmaceutical intermediates.​

6. Packaging and Storage​

6.1 Packaging​

• Galvanized Iron Drums: Commonly packaged in galvanized iron drums, with a common packaging specification of 170 kg per drum. The drums are tightly sealed to prevent leakage and evaporation of isooctanol.​

• Tank Trucks and Rail Tank Cars: For large - scale transportation, isooctanol can be transported in tank trucks or rail tank cars. These transportation containers are made of materials that can withstand the corrosion of isooctanol and are equipped with safety devices such as pressure relief valves and grounding devices to ensure safe transportation.​

6.2 Storage​

• Location: Store in a cool, well - ventilated warehouse. The storage temperature should be kept below 30 °C to reduce the risk of evaporation and the formation of explosive vapor - air mixtures.​

• Avoidance: Keep away from direct sunlight, heat sources, and ignition sources. It should be stored separately from strong oxidizing agents, strong acids, and alkalis to avoid chemical reactions.​

• Fire Protection: The storage area should be equipped with appropriate fire - fighting equipment, such as foam, dry - chemical, or carbon dioxide fire extinguishers. In case of a fire, these fire - fighting agents can effectively extinguish the fire. In addition, there should be emergency response plans and procedures in place to deal with potential accidents such as fires and spills.​

7. Toxicity and Safety Information​

7.1 Toxicity​

• Acute Toxicity: Isooctanol is of low - to - moderate toxicity. The median lethal dose (LD₅₀) for rats by oral administration is in the range of 2040 - 2500 mg/kg. Ingestion of large amounts may cause symptoms such as nausea, vomiting, headache, dizziness, and in severe cases, it can affect the central nervous system, leading to respiratory depression and coma.​

• Dermal Toxicity: Prolonged or repeated skin contact can cause skin irritation. It can defat the skin, resulting in dryness, redness, and cracking.​

• Inhalation Toxicity: Inhalation of its vapor can irritate the respiratory tract. At high concentrations, it may cause coughing, shortness of breath, and irritation of the nose and throat. The threshold limit value (TLV) in the workplace air, as recommended by relevant organizations, is usually set to limit the exposure level to protect workers' health.​

7.2 Safety Precautions​

• Engineering Controls: In workplaces where isooctanol is used or stored, install local exhaust ventilation or general dilution ventilation systems to keep the vapor concentration below the TLV. Use explosion - proof electrical equipment and lighting to prevent ignition of flammable vapors.​

• Personal Protective Equipment (PPE):​

• Respiratory Protection: When working in areas with potential high vapor concentrations, wear appropriate respiratory protection, such as air - purifying respirators with organic vapor cartridges.​

• Eye Protection: Use safety goggles or face shields to protect the eyes from splashes.​

• Skin Protection: Wear chemical - resistant gloves, protective clothing, and safety shoes to prevent skin contact.​

• Fire and Explosion Prevention: Since isooctanol is flammable, strictly prohibit smoking, open flames, and the use of non - explosion - proof electrical equipment in areas where it is present. Have fire - fighting plans and emergency response procedures in place, and train employees on how to respond to fires and spills.