- GRADE: Methylene diphenyl diisocyanate (MDI)
- Appearance: Dark Brown liquid
- NCO: 30.0-32.0 WT%
- Hydrolysable Chloride: Max. 0.2 WT%
- Acidity as HCL: Max. 0.05 WT%
- Viscosity at 25(°C) : 150-250 mPa.s
- PRODUCER: Karun Petrochemical Co
Methylene diphenyl diisocyanate (MDI)
Category: petrochemical products list
Description
Methylene Diphenyl Diisocyanate (MDI) is an aromatic diisocyanate with the chemical formula C₁₅H₁₀N₂O₂. It exists in three isomeric forms: 2,2′-MDI, 2,4′-MDI, and 4,4′-MDI, with 4,4′-MDI being the most commercially significant. This compound appears as a white or pale yellow solid at room temperature and has a melting point above 37°C. MDI is highly reactive with compounds containing active hydrogen atoms, such as polyols, forming rigid and flexible polyurethanes.
MDI is synthesized through the phosgenation of methylene diphenyl diamine (MDA). The resulting product undergoes purification to obtain the desired isomeric composition. Due to its high reactivity, MDI must be handled with care to prevent unwanted polymerization. In industrial settings, it is often stored in liquid form at elevated temperatures and protected from moisture to maintain its usability.
Polyurethane Foam:
MDI is a key ingredient in the production of both flexible and rigid polyurethane foams. Flexible foams are widely used in furniture, mattresses, and automotive seats due to their excellent cushioning properties and comfort. Rigid foams, on the other hand, are essential for insulation in construction, refrigeration, and packaging, offering superior thermal insulation and structural stability.
Coatings and Sealants:
MDI is used in the formulation of high-performance coatings and sealants. These products benefit from the durability, adhesion, and resistance to abrasion and chemicals that MDI imparts. Applications include protective coatings for floors, marine vessels, and industrial equipment, as well as sealants for construction and automotive industries where long-lasting protection is crucial.
Adhesives:
MDI-based adhesives are known for their strong bonding capabilities and resistance to moisture and chemicals. These adhesives are used in a variety of applications, from woodworking and furniture assembly to automotive and aerospace industries. The superior adhesive properties of MDI make it ideal for bonding a wide range of materials, including metals, plastics, and composites.
Elastomers:
MDI is also used in the production of polyurethane elastomers, which are prized for their elasticity, resilience, and abrasion resistance. These elastomers are found in a wide range of applications, such as wheels and tires, gaskets, seals, and bushings. The versatility of MDI-based elastomers allows them to be tailored for specific requirements, providing customized solutions for various industrial needs.
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High reactivity with polyols, makes it ideal for polyurethane production.
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Excellent physical properties, including high strength and durability.
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Versatile applications in various industries, from construction to automotive.
Handling MDI requires strict adherence to safety protocols. It can cause respiratory and skin irritation, so personal protective equipment (PPE) such as gloves, goggles, and respirators should be used. MDI should be stored in a cool, dry place, away from direct sunlight and moisture. Proper ventilation is essential to prevent inhalation of vapors during processing.
While MDI is a valuable industrial chemical, its production and use must be managed to minimize environmental impact. Emissions should be controlled to prevent air and water pollution, and waste should be disposed of according to environmental regulations. Additionally, innovations in recycling and waste reduction are essential to improve the sustainability of MDI-based products.
|
Property |
Unit |
Specification |
Test Method |
|
Appearance |
– |
Dark Brown Liquid |
Visual |
|
NCO |
WT% |
30.0-32.0 |
ASTM D5155-14 Method A |
|
Hydrolysable Chloride |
WT% |
Max 0.2 |
ASTM D4663-15 |
|
Acidity as HCL |
WT% |
Max 0.05 |
ASTM D6099-13 (High acidity) ASTM 5629-11 (Low acidity) |
|
Viscosity at 25(°C) |
mPa.s |
150-250 |
ASTM D4889-15 |
|
Specific Gravity at 25(°C) |
°C |
1.22-1.25 |
ASTM D4659-14 |
|
Isocyanate Equivalent Weight |
gr/eq |
131-140 |
ASTM D5155-14 Method A |
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