Maleic anhydride (C4H2O3) is a chemical compound used in various industries. It is produced by oxidizing benzene or butane. It is primarily employed in the production of polymers, resins, and agricultural chemicals.
| IUPAC Name | Maleic Anhydride |
| Molecular Formula | C4H2O3 |
| CAS Number | 108-31-6 |
| Synonyms | cis-Butenedioic Anhydride, 2,5-Furandione, Toxilic Anhydride, Maleic Acid Anhydride |
| InChI | InChI=1S/C4H2O3/c5-3-1-2-4(6)7-3/h1-2H |
Maleic Anhydride Properties
Maleic Anhydride Formula
The formula of maleic anhydride is C4H2O3. It consists of four carbon atoms, two hydrogen atoms, and three oxygen atoms. The arrangement of these atoms gives maleic anhydride its unique chemical properties.
Maleic Anhydride Molar Mass
The molar mass of butenedioic anhydride is calculated by summing the atomic masses of its constituent elements. Maleic anhydride has a molar mass of approximately 98.06 grams per mole. This value is essential for various calculations in chemistry and manufacturing processes.
Maleic Anhydride Boiling Point
Butenedioic anhydride has a boiling point of around 202.2 degrees Celsius (396.0 degrees Fahrenheit). This is the temperature at which the compound changes from a liquid to a gaseous state when heated. The boiling point is an important characteristic for determining the conditions required for its usage.
Maleic Anhydride Melting Point
The melting point of butenedioic anhydride is approximately 52.8 degrees Celsius (127.0 degrees Fahrenheit). This is the temperature at which the solid compound transforms into a liquid state. The melting point is a crucial parameter for handling and processing butenedioic anhydride.
Maleic Anhydride Density g/mL
The density of butenedioic anhydride is around 1.48 grams per milliliter (g/mL). Density measures the mass of a substance per unit volume. This value helps in understanding the concentration and behavior of butenedioic anhydride in various applications.
Maleic Anhydride Molecular Weight
The molecular weight of butenedioic anhydride is approximately 98.06 grams per mole. It is calculated by summing the atomic weights of its constituent atoms. Molecular weight is important for determining the amount of butenedioic anhydride required in reactions and for understanding its chemical properties.
Maleic Anhydride Structure
The structure of butenedioic anhydride consists of a cyclic molecule with a double bond between two carbon atoms and two oxygen atoms attached to the carbon skeleton. This structure imparts specific reactivity and characteristics to butenedioic anhydride, making it useful in various chemical processes.
Maleic Anhydride Solubility
Butenedioic anhydride is sparingly soluble in water but readily dissolves in organic solvents such as acetone, benzene, and ethyl acetate. This solubility behavior allows for easy incorporation of butenedioic anhydride into different solutions and facilitates its usage in various industrial applications.
| Appearance | White crystalline |
| Specific Gravity | 1.48 g/mL |
| Color | Colorless |
| Odor | Acrid odor |
| Molar Mass | 98.06 g/mol |
| Density | 1.48 g/mL |
| Melting Point | 52.8 °C (127.0 °F) |
| Boiling Point | 202.2 °C (396.0 °F) |
| Flash Point | 138 °C (280 °F) |
| Water Solubility | 44 g/L at 20 °C |
| Solubility | Soluble in organic solvents |
| Vapour Pressure | 0.3 mmHg at 20 °C |
| Vapour Density | 3.39 (Air = 1) |
| pKa | 1.2 |
| pH | ~1 (saturated solution) |
Maleic Anhydride Safety and Hazards
Butenedioic anhydride poses certain safety hazards and should be handled with caution. It can cause irritation to the skin, eyes, and respiratory system upon contact or inhalation. Direct skin contact may result in burns or dermatitis. Adequate protective measures such as gloves, goggles, and respiratory protection should be employed when working with this compound. It is important to avoid inhalation of its vapors or dust, as it can irritate the respiratory tract. Butenedioic anhydride should be stored in a cool, well-ventilated area, away from incompatible substances. Proper handling and adherence to safety protocols are essential to minimize the risks associated with this chemical.
| Hazard Symbols | Xi |
| Safety Description | Irritant |
| UN IDs | UN2215 |
| HS Code | 2917.12.000 |
| Hazard Class | 8 (Corrosive) |
| Packing Group | III |
| Toxicity | Harmful if swallowed or inhaled, causes irritation |
Maleic Anhydride Synthesis Methods
Various methods can synthesize butenedioic anhydride. One common method involves catalytically oxidizing benzene by reacting it with air or oxygen in the presence of a suitable catalyst, such as vanadium pentoxide or a metal oxide. The reaction occurs at elevated temperatures, typically around 300-400 degrees Celsius, and produces butenedioic anhydride.
Another method entails catalytically oxidizing butane or n-butane. This process employs catalysts like vanadium or molybdenum-based catalysts at high temperatures. It involves multiple reaction steps, including the formation of butenedioic acid as an intermediate, which undergoes dehydration to yield butenedioic anhydride.
The reaction of butenedioic acid with acetic anhydride is another method. In this case, butenedioic acid reacts with acetic anhydride in the presence of a catalyst like sulfuric acid. The reaction takes place under reflux conditions, resulting in the production of butenedioic anhydride as the final product.
In addition, the catalytic oxidation of hydrocarbons like n-butene or benzene derivatives such as ortho-xylene or meta-xylene allows for the synthesis of butenedioic anhydride. These reactions utilize similar conditions and catalysts mentioned earlier.
Choosing the appropriate synthesis method depends on factors like the availability of starting materials, desired production scale, and process economics. Each method has its own advantages and limitations in terms of cost, yield, and environmental considerations. Therefore, selecting the suitable synthesis method is crucial for efficiently producing butenedioic anhydride.
Maleic Anhydride Uses
Maleic anhydride finds numerous applications across various industries due to its versatile properties. Here are some key uses:
- Butenedioic anhydride plays a crucial role in producing polymers such as polybutylene succinate (PBS), unsaturated polyester resins, and alkyd resins. These polymers find applications in coatings, adhesives, and composite materials.
- It contributes to the creation of herbicides and pesticides, acting as an intermediate in synthesizing effective weed control agents like dicamba and butenedioic hydrazide.
- The pharmaceutical industry employs it in synthesizing various pharmaceutical intermediates and active ingredients, aiding in the development of drugs for treating hypertension, inflammation, and cancer.
- Butenedioic anhydride-based polymers actively serve as scale and corrosion inhibitors in water treatment processes, actively controlling mineral deposit buildup and actively safeguarding infrastructure.
- It finds utility in the production of sizing agents for the paper and paperboard industry, improving water resistance, printability, and strength of the paper.
- The textile industry utilizes it to manufacture textile auxiliaries, including colorants, dye-fixing agents, and finishing agents, enhancing color fastness and fabric performance.
- Butenedioic anhydride derivatives serve as food additives, functioning as gelling agents, stabilizers, or acidulants in various food products.
- They actively play a role in producing lubricant additives that actively enhance the performance and longevity of lubricating oils, actively improving their overall effectiveness.
The wide range of applications highlights the significance of butenedioic anhydride in various sectors, making it a valuable compound in industrial processes and product development.
Questions:
Q: What is the product of maleic anhydride and e e-2 4-hexadien-1-ol?
A: The product is a Diels-Alder adduct, specifically cis-N-ethyl-3-methyl-4-phenylsuccinimide.
Q: What is the role of maleic anhydride in the Diels-Alder reaction?
A: Butenedioic anhydride acts as the dienophile, reacting with dienes to form cyclic adducts.
Q: Does maleic anhydride harm aquatic organisms?
A: Yes, butenedioic anhydride can be harmful to aquatic organisms due to its toxicity and potential to cause adverse effects.
Q: If we use anthracene and maleic anhydride, what is the molar mass of the product?
A: The molar mass of the product formed from anthracene and butenedioic anhydride depends on the specific reaction and the resulting adduct.
Q: Is maleic anhydride aromatic?
A: Yes, butenedioic anhydride is considered aromatic due to the presence of a cyclic conjugated system.
Q: Why should maleic anhydride bottles be kept tightly closed when not in use?
A: Butenedioic anhydride is highly reactive and can readily undergo unwanted reactions with moisture and air. Keeping the bottles tightly closed helps prevent undesired reactions and maintain its quality.
Q: Is maleic anhydride polar?
A: Yes, butenedioic anhydride is polar due to the presence of polar functional groups, such as carbonyl groups, in its structure.
Q: Is maleic anhydride a dienophile?
A: Yes, butenedioic anhydride acts as a dienophile in Diels-Alder reactions, accepting dienes to form cycloadducts.
Q: Which diene would you expect to react most rapidly with maleic anhydride?
A: Dienes with increased electron density, such as those containing electron-donating substituents, would be expected to react more rapidly with butenedioic anhydride.
Q: How many esters are present in maleic anhydride?
A: Butenedioic anhydride does not contain esters. It is an anhydride of butenedioic acid, which does contain ester functionalities.