Methyl Cyclohexane
Methyl Cyclohexane: A Detailed Overview
Methyl cyclohexane (C₇H₁₄) is a saturated hydrocarbon, a colorless liquid with a faint odor, and an important chemical in various industrial applications. As an alkane, it belongs to the family of cycloalkanes, which are hydrocarbons with a cyclic structure, and specifically, it is a derivative of cyclohexane (C₆H₁₂) with one of the hydrogen atoms substituted by a methyl group (CH₃). Its chemical structure is often written as C₆H₁₁CH₃, emphasizing the cyclohexane ring with a methyl substituent attached.
1. Introduction to Methyl Cyclohexane
Methyl cyclohexane is commonly used as a solvent, in chemical synthesis, and as a reference compound in laboratories due to its relatively low toxicity and stability. While its uses are diverse, the compound’s chemical properties, such as its relatively low reactivity and hydrophobic nature, make it ideal in situations where a non-polar solvent is required. Additionally, methyl cyclohexane is of particular interest in petrochemical refining processes and as a fuel additive in some high-performance fuel blends.
2. Physical and Chemical Properties
Understanding the physical and chemical properties of methylcyclohexane is essential for evaluating its industrial applications, handling, and safety considerations.
- Chemical Formula: C₇H₁₄
- Molecular Weight: 98.19 g/mol
- Appearance: Colorless liquid
- Odor: Mild, sweet odor
- Boiling Point: 101°C (214°F)
- Melting Point: -126°C (-195°F)
- Density: 0.770 g/cm³ at 20°C
- Solubility: Insoluble in water; soluble in organic solvents such as alcohols, ethers, and hydrocarbons
- Vapor Pressure: 46 mmHg at 20°C
- Flash Point: -3°C (26.6°F)
- Autoignition Temperature: 259°C (498.2°F)
Methyl cyclohexane is classified as a non-polar solvent due to the lack of significant polarity within its molecular structure. As such, it is not miscible with water but is readily soluble in other non-polar or slightly polar organic solvents like hexane, toluene, and diethyl ether.
Its relatively low boiling point (101°C) and high volatility make it suitable for use in organic reactions where the solvent needs to be easily removed via distillation or evaporation. The compound’s melting point of -126°C means that it remains a liquid at most environmental and industrial temperatures, facilitating easy handling and storage.
From a reactivity standpoint, methyl cyclohexane is considered relatively inert, particularly under standard temperature and pressure conditions. This makes it a useful solvent for chemical reactions that involve highly reactive reagents, where an inert environment is essential. However, it can undergo combustion reactions in the presence of oxygen, releasing energy and forming carbon dioxide and water.
3. Production of Methyl Cyclohexane
Methyl cyclohexane is primarily produced from the hydrogenation of toluene. This process involves reacting toluene (C₆H₅CH₃) with hydrogen (H₂) in the presence of a catalyst (typically nickel or platinum) under elevated temperatures and pressures. The reaction proceeds as follows:
C6H5CH3+3H2→C6H11CH3
This hydrogenation process converts the aromatic ring of toluene into a saturated cyclohexane ring, resulting in methyl cyclohexane. The reaction is exothermic, meaning it releases heat, and the process is highly efficient, yielding high-purity methyl cyclohexane with minimal byproducts. The use of hydrogen gas in the process contributes to the cost of production, but the process is well-established and widely used in petrochemical industries.
Alternatively, methyl cyclohexane can be produced as a byproduct in the refining of crude oil. During the fractional distillation of petroleum, cycloalkanes (including methyl cyclohexane) are separated from other hydrocarbons based on their boiling points. The presence of methyl cyclohexane in crude oil fractions, particularly in naphtha, makes it accessible for recovery and use in industrial applications.
4. Applications of Methyl Cyclohexane
Methyl cyclohexane serves a variety of functions across different industries, most notably as a solvent, a fuel additive, and a chemical intermediate.
4.1 Solvent in Organic Synthesis
Methyl cyclohexane is a widely used non-polar solvent in organic chemistry due to its ability to dissolve a wide range of non-polar substances. It is particularly useful in reactions that require a stable, non-reactive environment. Because it does not participate in chemical reactions under most conditions, it is ideal for processes like:
- Recrystallization: Methyl cyclohexane can be used to purify organic compounds by dissolving them at high temperatures and allowing them to recrystallize as the solvent cools.
- Distillation: Its volatility and non-reactive nature make it a good solvent for use in distillation processes, where components of a mixture are separated based on their boiling points.
- Extraction: In laboratory settings, methyl cyclohexane is used in liquid-liquid extractions to separate compounds based on their polarity. It is particularly useful in the extraction of organic compounds from aqueous solutions.
4.2 Petrochemical Industry
In the petrochemical industry, methyl cyclohexane is used as a reference compound in the characterization of fuels and oils. Due to its well-defined properties, it serves as a standard for assessing the performance and quality of fuel mixtures. It is also employed in octane rating tests for gasoline, helping determine the anti-knock properties of fuels.
Moreover, methyl cyclohexane is present in some fuel blends as a high-energy-density hydrocarbon. While not as commonly used as compounds like iso-octane, it has been researched as a potential fuel or fuel additive, particularly in the context of high-performance aviation and racing fuels, where both energy content and combustion stability are critical.
4.3 Chemical Intermediate
Methyl cyclohexane can be used as a precursor or intermediate in the synthesis of other chemicals. It is particularly valuable in the manufacture of derivatives such as cyclohexylamine, which is an important intermediate for the production of corrosion inhibitors, herbicides, and antioxidants. Methyl cyclohexane’s relatively simple structure and stable nature make it an ideal starting material for various hydrogenation and substitution reactions.
4.4 Pharmaceutical and Cosmetics Industry
Although methyl cyclohexane is not a direct active ingredient in pharmaceuticals or cosmetic products, it is often used as a solvent in the formulation of these products. Its volatility ensures that it evaporates from the final product, leaving behind the active ingredients. In pharmaceuticals, it is used to extract plant-based compounds or to dissolve non-polar active ingredients during the manufacturing process.
In the cosmetics industry, methyl cyclohexane is sometimes employed as a solvent in the production of fragrances and personal care products. Its low toxicity and pleasant odor make it an attractive option for use in products that require a quick-drying solvent or carrier.
4.5 Polymer and Rubber Industry
Methyl cyclohexane is occasionally used as a solvent in the production of polymers and rubbers, where it can dissolve certain polymers and facilitate processes such as polymerization, film casting, and adhesive formulation. In rubber manufacturing, it may be used in the mixing and processing of rubber compounds to enhance flexibility and provide a medium for adding other chemicals or modifiers.
5. Environmental Impact and Safety
While methyl cyclohexane is widely used in various industries, its environmental and health impacts must be considered when handling and disposing of the compound.
5.1 Toxicity and Health Effects
Methyl cyclohexane is generally regarded as having low acute toxicity, but exposure to its vapors or liquid form can cause irritation to the skin, eyes, and respiratory system. Inhalation of methyl cyclohexane vapors can result in symptoms such as dizziness, headaches, and nausea. Long-term or repeated exposure can lead to more serious health issues, such as liver and kidney damage.
The compound has low toxicity when ingested, but ingestion can still lead to gastrointestinal distress, and aspiration into the lungs could cause serious harm, including chemical pneumonitis. As a result, strict safety protocols are recommended when handling methyl cyclohexane, including the use of personal protective equipment (PPE) such as gloves, goggles, and respiratory protection in areas with high vapor concentrations.
5.2 Environmental Effects
Methyl cyclohexane is classified as a volatile organic compound (VOC), and when released into the atmosphere, it can contribute to air pollution and the formation of ground-level ozone, a key component of smog. However, due to its low toxicity and relatively short atmospheric lifetime, it does not persist in the environment for long and is not considered a significant environmental hazard.
In water, methyl cyclohexane is insoluble, and if released into aquatic environments, it can form a film on the surface, preventing the proper exchange of gases between water and air, which can harm aquatic life. Its release into soil can lead to contamination of groundwater and harm to plants and animals. Therefore, spills and leaks must be promptly contained and cleaned up to minimize environmental damage.
5.3 Flammability and Fire Hazards
Methyl cyclohexane is highly flammable, with a low flash point of -3°C, meaning it can ignite easily when exposed to heat, sparks, or open flames. Its vapor is heavier than air and can travel along the ground, where it can be ignited by distant sources of ignition. For this reason, methyl cyclohexane should be stored and handled in well-ventilated areas away from sources of ignition.
Firefighting measures for methyl cyclohexane include the use of dry chemical, foam, or carbon dioxide extinguishers. Water is generally not recommended as it can spread the burning liquid. In the event of a fire, emergency responders should wear full protective gear, including self-contained breathing apparatus, due to the potential release of toxic fumes such as carbon monoxide during combustion.
6. Regulatory Aspects
Methyl cyclohexane is regulated by various environmental and occupational safety laws due to its flammability and potential health effects. In the United States, the Occupational Safety and Health Administration (OSHA) sets permissible exposure limits (PELs) to ensure worker safety. In Europe, methyl cyclohexane is subject to the REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) regulation, which requires manufacturers and importers to assess the risks associated with its use.
7. PT. Samiraschem Indonesia is Reliable Supplier and Distributor with High Quality Product and Good Price. We are Serving and Delivered Area such Jakarta Bandung Semarang Jogja Surabaya Medan and Batam
Methyl cyclohexane is a versatile hydrocarbon with applications in multiple industries, including petrochemicals, pharmaceuticals, and cosmetics. Its non-polar nature, low reactivity, and stability make it a useful solvent, while its relatively low toxicity and environmental impact enhance its suitability for widespread use. However, its flammability and potential health risks necessitate proper handling and regulatory oversight to ensure safe usage in industrial and laboratory settings.
Future trends may see continued use of methyl cyclohexane in traditional applications, but increasing attention to environmental sustainability could drive innovation in finding safer and more eco-friendly alternatives.