O-Phthalic Anhydride (CAS: 85-44-9) is an organic compound with the chemical formula C₆H₄(CO)₂O. It is a colorless, crystalline solid that has a strong, pungent odor and is used primarily in the production of phthalic acid derivatives.
Key Properties:
- Appearance: O-Phthalic anhydride is a colorless or white crystalline solid.
- Point de fusion: It melts at 131°C (268°F).
- Point d'ébullition: Its boiling point is approximately 337°C (639°F).
- Solubility: It is slightly soluble in water but more readily soluble in organic solvents such as alcohols, ethers, and benzene.
- Odor: It has a strong, odeur âcre, often described as sharp or acrid.
Common Uses:
- Production of Phthalic Acid Derivatives: O-Phthalic anhydride is primarily used in the production of phthalic acid and its derivatives, which are key intermediates in manufacturing plasticizers (like di(2-ethylhexyl)phthalate, or DEHP), dyes, and resins.
- Polyester Resins: It is used in the production of unsaturated polyester resins. These resins are crucial for manufacturing fiberglass, automotive parts, and coatings.
- Flame Retardants: O-Phthalic anhydride is involved in producing certain flame retardants, which are added to plastics, textiles, and coatings to improve their resistance to fire.
- Plasticizers: It is also used in producing plasticizers, particularly phthalates, which are added to plastics to increase flexibility, durability, and workability.
- Alkyd Resins: The compound is used in making alkyd resins that are utilized in paints, varnishes, and other coatings.
Health and Safety:
- Toxicity: O-Phthalic anhydride can cause skin irritation, respiratory issues, and eye damage upon exposure. Inhalation of its fumes or dust should be avoided.
- Environmental Impact: It should be handled with care, as improper disposal can lead to pollution, particularly in aquatic environments.
Conclusion:
O-Phthalic anhydride is a versatile chemical compound primarily used in the production of phthalic acid derivatives, polyester resins, and plasticizers. It plays a critical role in the manufacture of plastics, coatings, and fibers. Cependant, due to its toxicity and environmental concerns, safe handling and disposal practices are essential.
