Commonly used alkane solvents are mainly divided into two categories: aliphatic alkanes and cycloalkanes. Specific types commonly used in daily industrial and chemical applications are as follows:
1. Aliphatic Alkanes
These are straight-chain or branched saturated aliphatic hydrocarbons and are the most widely used type of alkane solvent:
• n-Hexane: Low boiling point, strong dissolving power, commonly used in industrial cleaning and adhesive dilution. Note that long-term exposure may pose a neurotoxic risk.
- n-Heptane: Slightly higher boiling point than n-hexane, with a milder odor, often used in cosmetics, fragrance extraction, and precision electronic cleaning.
- Pentane (n-pentane, isopentane): Extremely volatile, commonly used in foaming agents, aerosol propellants, and can also be used as a solvent to dilute inks.
- Octane (n-octane, isooctane): Isooctane is the standard substance for gasoline antiknock agents. Industrial-grade octane is often used as a solvent for coatings and rubber.
- Dodecane: Commonly used in metalworking fluids, textile auxiliaries, and as a base solvent for formulating industrial cleaning agents. White oil (liquid paraffin): Composed of a mixture of C10-C18 alkanes, it is safe and odorless, widely used in daily chemical skincare, food processing aids, and pharmaceutical solvents.
2. Cycloalkanes as solvents: Saturated alkanes with cyclic structures have stronger dissolving power than aliphatic hydrocarbons and lower toxicity:
- Cyclohexane: Commonly used as an organic synthesis solvent, paint thinner, and also an excellent solvent for adhesives.
- Methylcyclohexane: Has better dissolving power than cyclohexane and lower toxicity; commonly used as a solvent for automotive coatings and printing inks.
- Decahydronaphthalene: A high-boiling-point cycloalkanes solvent with extremely strong dissolving power; used for dissolving resins and rubber, and for cleaning industrial oil stains.
- Cyclopentane: Used as an environmentally friendly foaming agent to replace Freon; also used in adhesives and paint solvents.
3. Mixed alkane solvents: Composed of alkanes with different chain lengths, suitable for dissolving and evaporating in different scenarios:
- Solvent oils: such as 6#, 120#, and 200# solvent gasoline, are all mixed alkane solvents, widely used in the coatings, rubber, and ink industries.
- Isoparaffin solvents: such as the Isopar series and Shellsol series, are mixed products of branched alkanes, with low odor and low toxicity, commonly used in high-end daily chemicals, electronic cleaning, and food packaging inks.