What Is Butyl Acetate?
Butyl acetate, the ester of acetic acid and butanol with the molecular formula C6H12O2, is commonly known as butyl acetate. It is a clear, colorless liquid with a distinctive sweet, fruity odor. Its molecular weight is 116.16 g/mol, and it has the CAS number 123-86-4.
Butyl acetate is highly soluble in ethanol but insoluble in water. It exists in four structural isomers: n-butyl acetate, isobutyl acetate, sec-butyl acetate, and tert-butyl acetate, each with its own unique properties.
Uses of Butyl Acetate
Butyl acetate finds extensive use as a solvent across various applications. It is commonly employed in paints, inks, resins, cosmetics, pharmaceuticals, adhesives, fragrances, leather, enamel, shoe polish, and rubber.
In the paint and ink industry, butyl acetate serves as a heavy solvent with a relatively high boiling point, contributing to better flow and brush resistance. It is often blended with other solvents of lower volatility to adjust drying characteristics. For instance, it is commonly combined with ethyl acetate in nail polish formulations.
Additionally, butyl acetate is favored as a solvent in lacquers due to its excellent flowability and brush resistance on resin-coated surfaces, offering compatibility with materials like cellulose nitrate, ethyl cellulose, polystyrene, and methyl methacrylate resin.
Its pleasant aroma also makes it a valuable ingredient in the food industry for flavoring agents, fruit essences, and spices, enhancing the taste of various products such as candy, ice cream, and cheese.
Properties of Butyl Acetate
Butyl acetate has a melting point of -74°C and a boiling point of 124°C. Despite its relatively high boiling point, its vapor pressure at room temperature is sufficient for it to emit its characteristic aroma.
The different structural isomers of butyl acetate exhibit distinct odors, with n-butyl acetate and isobutyl acetate presenting apple or banana-like scents, while tert-butyl acetate has a blueberry-like aroma. These variations allow for specific applications in fragrance compositions.
Naturally, butyl acetate is present as a volatile aroma component in fruits like grapes, strawberries, and apples.
Other Information on Butyl Acetate
1. Safety and Regulations
While butyl acetate is generally considered safe for humans and the environment, it may cause irritation to the eyes and respiratory tract. Inhalation of high concentrations can lead to symptoms such as headache, nausea, dizziness, and difficulty breathing.
Due to its flammability, butyl acetate is classified as a hazardous substance and should be handled with caution. Storage and use are subject to regulations to prevent fire hazards and ensure safe handling practices.
2. Manufacturing Process
Industrial production of butyl acetate involves an esterification reaction between acetic acid and butanol, typically using an acid catalyst such as sulfuric acid. The crude product undergoes distillation to remove impurities, yielding purified butyl acetate suitable for various applications.
For high-purity applications, additional distillation steps may be employed to remove specific impurities, ensuring the quality required for food-grade or electronic applications.