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Send EmailMethylene Diphenyl Diisocyanate, Monomeric MDI, Polymeric MDI, Modified MDI, 101-68-8, 2536-05-2, 26447-40-5
METHYLENE DIPHENYL DIISOCYANATE (MDI)
PRODUCT IDENTIFICATION INFORMATION
| Parameter | Information |
|---|---|
| Product Name | Methylene Diphenyl Diisocyanate |
| Chemical Name (IUPAC) | 4,4'-Methylene diphenyl diisocyanate (monomeric) |
| Synonyms (Turkish) | Metilen Difenil Diizosiyanat, MDI, Monomerik MDI, Polimerik MDI, Modifiye MDI |
| Synonyms (English) | Methylene Diphenyl Diisocyanate, MDI, Monomeric MDI, Polymeric MDI, Modified MDI, Diphenylmethane Diisocyanate |
| CAS Numbers | 101-68-8 (4,4'-MDI), 2536-05-2 (2,4'-MDI), 26447-40-5 (polymeric MDI) |
| EC Numbers | 202-966-0 (4,4'-MDI), 219-799-4 (2,4'-MDI), 247-714-0 (polymeric MDI) |
| Molecular Formula | C₁₅H₁₀N₂O₂ (monomeric MDI) |
| Molecular Weight | 250.26 g/mol (monomeric MDI) |
| Appearance (25°C) | Monomeric MDI: White to pale yellow solid/molten liquid; Polymeric MDI: Brownish-yellow liquid |
CHEMICAL STRUCTURE
4,4'-Methylene Diphenyl Diisocyanate (MDI)
OCN — C₆H₄ — CH₂ — C₆H₄ — NCO
Molecular Formula: C₁₅H₁₀N₂O₂ (monomeric MDI)
SMILES: O=C=Nc1ccc(cc1)Cc2ccc(cc2)N=C=O
InChI: InChI=1S/C15H10N2O2/c18-10-16-14-5-1-12(2-6-14)9-13-3-7-15(8-4-13)17-11-19/h1-8H,9H2
InChIKey: RUIGNSMKCNZORC-UHFFFAOYSA-N
Structure: Two aromatic rings connected by a methylene bridge (-CH₂-); Each aromatic ring has an isocyanate group (-NCO); Monomeric MDI (4,4'-isomer) has linear and symmetric structure.
SECTION 1: CHEMICAL IDENTITY AND DESCRIPTION
| Parameter | Information |
|---|---|
| Product Name | Methylene Diphenyl Diisocyanate |
| Chemical Name (IUPAC) | 4,4'-Methylene diphenyl diisocyanate (monomeric) |
| Synonyms (Turkish) | Metilen Difenil Diizosiyanat, MDI, Monomerik MDI, Polimerik MDI, Modifiye MDI |
| Synonyms (English) | Methylene Diphenyl Diisocyanate, MDI, Monomeric MDI, Polymeric MDI, Modified MDI, Diphenylmethane Diisocyanate |
| CAS Numbers | 101-68-8 (4,4'-MDI), 2536-05-2 (2,4'-MDI), 26447-40-5 (polymeric MDI) |
| EC Numbers | 202-966-0 (4,4'-MDI), 219-799-4 (2,4'-MDI), 247-714-0 (polymeric MDI) |
| Molecular Formula | C₁₅H₁₀N₂O₂ (monomeric MDI) |
| Molecular Weight | 250.26 g/mol (monomeric MDI) |
| Chemical Class | Aromatic diisocyanate; Isocyanate compound |
| Physical State (25°C) | Solid (monomeric) / Liquid (polymeric, modified) |
| Odor | Sharp, characteristic, pungent |
| Color | Monomeric: White to pale yellow; Polymeric: Brownish-yellow |
SECTION 2: MDI TYPES AND COMPARISON
| Parameter | Monomeric MDI (4,4'-MDI) | Polymeric MDI (PMDI) | Modified MDI |
|---|---|---|---|
| CAS Number | 101-68-8 | 26447-40-5 | Variable |
| Appearance (25°C) | White to pale yellow solid/molten liquid | Brownish-yellow liquid | Light yellow to brownish liquid |
| Functionality (f) | 2 | 2.3 – 3.0 | 2 – 2.5 |
| Isocyanate Content (%NCO) | ~33.6 | 30 – 32 | 28 – 32 |
| Freezing Point | ~38 – 40°C | <0°C (typically liquid) | <0°C |
| Viscosity (25°C) | 5 – 15 mPa·s (molten) | 150 – 300 mPa·s | 20 – 200 mPa·s |
| Density (25°C) | ~1.19 g/cm³ | ~1.22 g/cm³ | ~1.20 g/cm³ |
| Flash Point | >200°C | >200°C | >200°C |
| Reactivity with Water | High | High | High |
| Primary Use | Elastomers, adhesives, coatings | Rigid and flexible foams, panels | Coatings, adhesives, specialty applications |
SECTION 3: PHYSICAL AND CHEMICAL PROPERTIES
| Property | Monomeric MDI | Polymeric MDI | Test Method / Note |
|---|---|---|---|
| Appearance | White to pale yellow solid/molten liquid | Brownish-yellow liquid | Visual |
| Odor | Sharp, characteristic | Sharp, characteristic | Olfactometric |
| Molecular Weight | 250.26 g/mol | Oligomer mixture | Calculated / GPC |
| Functionality | 2 | 2.3 – 3.0 | – |
| Isocyanate Content (%NCO) | ~33.6 | 30 – 32 | Titrimetric |
| Freezing Point | ~38 – 40°C | <0°C | DSC |
| Viscosity (25°C) | 5 – 15 mPa·s (molten) | 150 – 300 mPa·s | Brookfield |
| Density (25°C) | ~1.19 g/cm³ | ~1.22 g/cm³ | ASTM D4052 |
| Flash Point | >200°C | >200°C | Pensky-Martens |
| Vapor Pressure (25°C) | ~1.0 x 10⁻⁵ mmHg | ~1.0 x 10⁻⁵ mmHg | – |
| Solubility in Water | Reacts (CO₂ evolution) | Reacts (CO₂ evolution) | General Method |
| Solubility in Organic Solvents | Toluene, acetone, DMF, ketones | Toluene, acetone, DMF, ketones | General Method |
| pH | Reacts; Not applicable | Reacts; Not applicable | – |
| Reactivity | High with water, alcohols, amines, bases | High with water, alcohols, amines, bases | – |
| Stability | Stable under normal conditions; Reacts with moisture | Stable under normal conditions; Reacts with moisture | – |
| Shelf Life | 6 – 12 months (original packaging) | 6 – 12 months (original packaging) | – |
SECTION 4: CHEMICAL PROPERTIES AND REACTIVITY
| Parameter | Information |
|---|---|
| Chemical Character | Aromatic diisocyanate; High reactivity; Reacts with water, alcohols, amines, and compounds containing active hydrogen |
| Stability | Stable under normal conditions; Reacts with moisture (CO₂ evolution); Decomposes at high temperatures |
| Reactivity | Reacts with water to form polyurea and CO₂; Reacts with alcohols to form urethanes; Reacts with amines to form ureas; Exothermic reaction with bases; Polymerization with active hydrogen compounds |
| Incompatible Materials | Water (violent reaction, CO₂), alcohols (urethane formation), amines (urea formation), strong bases (exothermic), acids, oxidizing agents |
| Polymerization | Polymerizes with polyols and active hydrogen compounds to form polyurethane |
| Decomposition Products (Heating) | Carbon monoxide, carbon dioxide, nitrogen oxides (NOx), isocyanate vapors, aromatic compounds |
| Water Reaction | R-NCO + H₂O → R-NH₂ + CO₂ → R-NH-CO-NH-R (polyurea) |
| Alcohol Reaction | R-NCO + R'-OH → R-NH-COO-R' (urethane) |
| Amine Reaction | R-NCO + R'-NH₂ → R-NH-CO-NH-R' (urea) |
| Trimerization | Forms isocyanurate rings when heated with catalysts |
| Hydrolysis | Slow hydrolysis with moisture; Causes polyurethane degradation |
| Complex Formation | Forms complexes with active hydrogen compounds |
| Carbonation | Reacts with CO₂ (carbamate formation) |
SECTION 5: PRODUCTION METHODS
Method 1: Phosgenation Process (Aniline and Formaldehyde)
Reaction: 2C₆H₅NH₂ (aniline) + CH₂O → H₂N-C₆H₄-CH₂-C₆H₄-NH₂ (MDA) + 2COCl₂ (phosgene) → OCN-C₆H₄-CH₂-C₆H₄-NCO (MDI)
Description: Aniline and formaldehyde are reacted with hydrochloric acid catalyst to form methylene diphenyl diamine (MDA); MDA is reacted with phosgene to form MDI (phosgenation); Purified by distillation; Monomeric MDI (4,4' and 2,4' isomers) and polymeric MDI mixture are obtained. Most common industrial method.
Method 2: Carbamate Route (Phosgene-Free Process)
Process: Aniline + Dimethyl carbonate → Methyl phenyl carbamate → Thermal decomposition → MDI
Description: Aniline is reacted with dimethyl carbonate (without phosgene) to form methyl phenyl carbamate; Carbamate is thermally decomposed to obtain MDI; More environmentally friendly method eliminating phosgene use; Less commercially widespread.
Method 3: Modified MDI Production
Process: Monomeric MDI + Modifying agent → Modified MDI
Description: Monomeric MDI is modified with carbodiimide, uretdione, or urethane-forming agents; Freezing point is reduced to obtain liquid form; Used for coatings, adhesives, and specialty applications.
SECTION 6: FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION
| Property | Description |
|---|---|
| Polymerization / Polyurethane Formation | Reacts with polyols and active hydrogen compounds to form polyurethane; Key building block for flexible and rigid foams, elastomers, coatings, and adhesives |
| Foam Formation (Flexible/Rigid) | Reacts with water or blowing agents to generate CO₂ gas; This gas creates cellular structure in the polymer matrix; Produces flexible foams (furniture, bedding) and rigid foams (insulation, panels) |
| Adhesive and Binder | Reacts with active hydrogen groups on surfaces to form strong chemical bonds; Used as adhesive for wood, metal, plastic, and composite materials; Acts as binder in wood composites |
| Coating and Sealant | Reacts with polyols to form durable, flexible, and chemical-resistant coatings; Used in floor coatings, industrial coatings, and sealants |
| Elastomer Production | Reacts with long-chain polyols to form flexible, durable elastomers; Used in wheels, rollers, seals, and vibration-damping components |
| Crosslinking Agent | Forms crosslinks between polymer chains to improve mechanical properties; Increases thermal and chemical resistance of polymers |
| High Functionality (PMDI) | Higher functionality (f=2.3-3.0) provides more crosslinking; Ideal for rigid foams and structural applications |
| Modification (Modified MDI) | Reduced freezing point; Easier to handle liquid form; Suitable for coatings, adhesives, and specialty applications |
SECTION 7: MAIN APPLICATION AREAS
| Industry / Application | Function | Typical Use |
|---|---|---|
| Flexible Polyurethane Foam | Foam former | Furniture, bedding, automotive seating, sponges |
| Rigid Polyurethane Foam | Insulation material | Building insulation, sandwich panels, refrigeration, refrigerators, thermal insulation |
| Elastomers | Polymerization | Wheels, rollers, seals, vibration dampers, sports equipment |
| Adhesives and Sealants | Binder | Industrial adhesives, automotive, construction, wood composites, lamination |
| Coatings | Film former | Floor coatings, industrial coatings, protective coatings, paints |
| Wood Composites | Binder | OSB (Oriented Strand Board), particleboard, MDF, wood-plastic composites |
| Automotive | Component production | Seat foam, steering wheels, interior trim, bumpers, air filters |
| Construction | Insulation, coating | Rigid foam panels, roof insulation, floor coatings, waterproofing |
| Footwear Industry | Foam and elastomer | Shoe soles, insoles |
| Casting and Molding | Binder | Resin casting, mold making |
SECTION 8: QUALITY SPECIFICATIONS
| Parameter | Monomeric MDI | Polymeric MDI | Modified MDI | Test Method |
|---|---|---|---|---|
| Appearance (25°C) | White to pale yellow solid/molten liquid | Brownish-yellow liquid | Light yellow liquid | Visual |
| Isocyanate Content (%NCO) | 33.0 – 34.0 | 30.0 – 32.0 | 28.0 – 32.0 | Titrimetric |
| Freezing Point | 38 – 40°C | <0°C | <0°C | DSC |
| Viscosity (25°C) | 5 – 15 mPa·s (molten) | 150 – 300 mPa·s | 20 – 200 mPa·s | Brookfield |
| Density (25°C) | 1.18 – 1.20 g/cm³ | 1.21 – 1.23 g/cm³ | 1.18 – 1.22 g/cm³ | ASTM D4052 |
| Acidity (as HCl) | ≤ 0.01% | ≤ 0.01% | ≤ 0.01% | Titrimetric |
| Hydrolyzable Chlorine | ≤ 0.03% | ≤ 0.03% | ≤ 0.03% | Titrimetric |
| Isomer Content (4,4' / 2,4') | ≥ 98% (4,4') | Variable | Variable | GC |
| Functionality | 2.0 | 2.3 – 3.0 | 2.0 – 2.5 | – |
| Color (APHA) | ≤ 30 | Variable | ≤ 50 | ASTM D1209 |
| Moisture Content | ≤ 0.03% | ≤ 0.03% | ≤ 0.03% | Karl Fischer |
SECTION 9: TOXICOLOGICAL PROFILE
| Parameter | Value |
|---|---|
| Acute Oral Toxicity (LD50, Rat) | ~ 2,000 – 5,000 mg/kg (moderate toxicity) |
| Acute Dermal Toxicity (LD50, Rabbit) | > 5,000 mg/kg (low dermal toxicity) |
| Acute Inhalation Toxicity (LC50, Rat) | ~ 0.3 – 0.5 mg/L (4 hours) |
| Skin Irritation | Mild to moderate irritation; Sensitizer (H317) |
| Eye Irritation | Serious irritation; Risk of damage |
| Respiratory Irritation | Respiratory tract irritation; Sensitizer (H334) |
| Chronic Toxicity | Repeated exposure may lead to respiratory sensitization (asthma); Skin sensitization (allergic contact dermatitis) |
| Carcinogenicity | Not classified as carcinogenic (IARC Group 3: Not classifiable) |
| Mutagenicity | Not classified as mutagenic |
| Reproductive Toxicity | Not classified as reproductive toxic |
| Target Organs | Lungs, respiratory system, skin, eyes |
| Occupational Exposure Limit (8h TWA) | ACGIH TLV: 0.005 ppm (0.051 mg/m³) (sensitizer) |
| Special Toxicity Note | Respiratory sensitizer (H334) – May cause asthma-like symptoms, breathing difficulties; Skin sensitizer (H317) – Allergic contact dermatitis; Sensitized individuals may react at very low concentrations; Avoid breathing vapors and aerosol; Adequate ventilation and PPE are required |
SECTION 10: GHS CLASSIFICATION AND LABELING
GHS Classification (in accordance with CLP and UN GHS):
| Hazard Class | Category | H-Statement |
|---|---|---|
| Acute Toxicity (Inhalation) | Category 4 | H332 |
| Skin Irritation | Category 2 | H315 |
| Skin Sensitization | Category 1 | H317 |
| Serious Eye Damage | Category 1 | H318 |
| Respiratory Sensitization | Category 1 | H334 |
| Specific Target Organ Toxicity (Single Exposure) | Category 3 | H335 |
| Aquatic Toxicity (Chronic) | Category 2 | H411 |
Signal Word: DANGER
Hazard Pictograms: GHS05 (Corrosion), GHS07 (Exclamation Mark), GHS08 (Health Hazard)
Hazard Statements (H-Codes):
| Code | Statement |
|---|---|
| H315 | Causes skin irritation |
| H317 | May cause an allergic skin reaction |
| H318 | Causes serious eye damage |
| H332 | Harmful if inhaled |
| H334 | May cause allergy or asthma symptoms or breathing difficulties if inhaled |
| H335 | May cause respiratory irritation |
| H411 | Toxic to aquatic life with long-lasting effects |
NFPA 704 Hazard Classification:
| Health | Flammability | Reactivity | Special |
|---|---|---|---|
| 3 | 1 | 1 | - |
| (Serious health hazard – sensitizer) | (Combustible – must be heated) | (Reactive – water reaction) | (None) |
UN Number: UN 2489 (Methylene diphenyl diisocyanate, liquid) / UN 2209 (Methylene diphenyl diisocyanate, solid)
SECTION 11: PRECAUTIONARY STATEMENTS (P-CODES)
| Code | Statement |
|---|---|
| P260 | Do not breathe dust/fume/gas/mist/vapors/spray |
| P264 | Wash hands thoroughly after handling |
| P271 | Use only outdoors or in a well-ventilated area |
| P272 | Contaminated work clothing should not be allowed out of the workplace |
| P280 | Wear protective gloves/protective clothing/eye protection/face protection |
| P285 | In case of inadequate ventilation, wear respiratory protection |
| P301+P312 | IF SWALLOWED: Call a POISON CENTER/doctor if you feel unwell |
| P302+P352 | IF ON SKIN: Wash with plenty of soap and water |
| P304+P340 | IF INHALED: Remove person to fresh air and keep comfortable for breathing |
| P305+P351+P338 | IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and continue rinsing |
| P310 | Immediately call a POISON CENTER/doctor |
| P333+P313 | If skin irritation or rash occurs: Get medical advice/attention |
| P337+P313 | If eye irritation persists: Get medical advice/attention |
| P342+P311 | If experiencing respiratory symptoms: Call a POISON CENTER/doctor |
| P362+P364 | Take off contaminated clothing and wash it before reuse |
| P403+P233 | Store in a well-ventilated place. Keep container tightly closed |
| P501 | Dispose of contents/container in accordance with local/regional/national/international regulations |
SECTION 12: FIRST AID MEASURES
| Exposure Route | Action to Take |
|---|---|
| Inhalation | Remove to fresh air immediately. If breathing is difficult, give oxygen. If respiratory symptoms (cough, wheezing, shortness of breath) occur, seek immediate medical attention. Avoid repeated exposure due to sensitization risk. |
| Skin Contact | Remove contaminated clothing immediately. Wash skin with plenty of soap and water for at least 15 minutes. If irritation or rash develops, seek medical attention. Allergic contact dermatitis may develop. |
| Eye Contact | Rinse immediately with plenty of water for at least 15 minutes. Keep eyelids open. Remove contact lenses if present. Seek immediate medical attention (H318). |
| Ingestion | Rinse mouth. Do NOT induce vomiting (aspiration risk and chemical pneumonitis risk). Drink plenty of water. Seek immediate medical attention. |
| General | Sensitizer – may cause respiratory and skin allergies; Avoid repeated exposures; Under medical surveillance. |
SECTION 13: FIREFIGHTING MEASURES
| Parameter | Information |
|---|---|
| Fire Hazard | Combustible liquid/solid (when heated). Flash point >200°C. |
| Hazards Arising from Fire | Thermal decomposition produces toxic and irritating gases: isocyanate vapors, hydrogen cyanide (HCN), nitrogen oxides (NOx), carbon monoxide (CO) |
| Suitable Extinguishing Media | CO₂, dry chemical powder, foam, water spray. |
| Unsuitable Extinguishing Media | Water jet (may spread fire) |
| Special Protective Equipment | Self-contained breathing apparatus (SCBA), full protective clothing (chemical-resistant). |
| Special Precautions | Prevent firefighting water from entering sewers and waterways. Closed containers should be cooled with water. |
SECTION 14: STORAGE AND SHELF LIFE
| Parameter | Information |
|---|---|
| Storage Conditions | Store in a cool, dry, well-ventilated area; PROTECT FROM MOISTURE (reaction risk); Monomeric MDI: Keep molten at 40-50°C or solid under inert gas (N₂); Polymeric MDI: Store as liquid at 10-35°C. |
| Container Requirements | Tightly closed, moisture-proof containers (stainless steel, suitable polyethylene, under inert gas (N₂)). |
| Materials to Protect From | Moisture, water, alcohols, amines, bases, acids, oxidizing agents, heat |
| Shelf Life | 6 – 12 months (in unopened original packaging, under proper storage conditions). |
| Stability Note | Reacts with moisture to release CO₂ and causes quality loss; Must be stored under inert gas (N₂); Containers must be kept tightly closed. |
| Special Storage Requirements | Store in a well-ventilated area; Protect from moisture; Temperature-controlled storage for monomeric MDI (40-50°C) or solid under inert gas; Store separately from incompatible materials; Use only dry inert gas (N₂). |
SECTION 15: PACKAGING OPTIONS
| Packaging Type | Quantity | Material |
|---|---|---|
| Plastic Drum (Monomeric MDI) | 200 kg | Stainless steel-lined drum (molten) |
| Steel Drum (Polymeric MDI) | 200 kg, 250 kg | Stainless steel or lined carbon steel (under N₂) |
| IBC Container | 1000 kg, 1200 kg | Stainless steel or lined carbon steel (under N₂) |
| Bulk Tanker | 10,000 – 25,000 L | Stainless steel (isothermal / temperature-controlled) |
| Small Pack | 1 L, 5 L | Stainless steel or glass (laboratory/sample) |
SECTION 16: TRANSPORT INFORMATION
| Parameter | Information |
|---|---|
| UN Number | UN 2489 (Methylene diphenyl diisocyanate, liquid) / UN 2209 (Methylene diphenyl diisocyanate, solid) |
| Hazard Class | 6.1 (Toxic substances) |
| Subsidiary Hazard | 8 (Corrosive) |
| Packing Group | III |
| ADR/RID | Class 6.1, PG III, UN 2489 / UN 2209 |
| IMDG Code | Class 6.1, PG III, UN 2489 / UN 2209 (Marine Pollutant: Yes) |
| IATA (Air) | Class 6.1, PG III, UN 2489 / UN 2209 |
| Marine Pollutant | Yes |
| Transport Temperature | Monomeric MDI: 40-50°C (molten) or solid; Polymeric MDI: 10-35°C; Protect from moisture. |
SECTION 17: REGULATORY STATUS
| Region / Authority | Status |
|---|---|
| European Union | REACH registered; Respiratory and skin sensitizer (H334, H317); Corrosive; OEL: 0.005 ppm (sensitizer) |
| USA (TSCA) | Listed (TSCA Inventory) |
| USA (EPA) | Regulated as hazardous substance; EPCRA 313 reporting |
| USA (OSHA) | Regulated as sensitizer; PEL: 0.02 ppm (ceiling) |
| Turkey | Industrial chemical; Subject to KKDIK regulation; Respiratory and skin sensitizer |
| IARC | Group 3 (Not classifiable as carcinogenic to humans) |
| NTP | Not listed |
| California (Prop 65) | Not listed |
| EU OEL | 0.005 ppm (8h TWA); 0.01 ppm (STEL) (sensitizer) |
| MAK (Germany) | 0.005 ppm (sensitizer) |
SECTION 18: OTHER NAMES AND SYNONYMS
| Type | Name |
|---|---|
| Turkish Names | Metilen Difenil Diizosiyanat, MDI, Monomerik MDI, Polimerik MDI, Modifiye MDI |
| English Names | Methylene Diphenyl Diisocyanate, MDI, Monomeric MDI, Polymeric MDI, Modified MDI, Diphenylmethane Diisocyanate |
| Chemical Names | 4,4'-Methylene diphenyl diisocyanate; 4,4'-Diphenylmethane diisocyanate; Bis(4-isocyanatophenyl)methane |
| CAS Numbers | 101-68-8 (4,4'-MDI); 2536-05-2 (2,4'-MDI); 26447-40-5 (polymeric MDI) |
| EC Numbers | 202-966-0 (4,4'-MDI); 219-799-4 (2,4'-MDI); 247-714-0 (polymeric MDI) |
| Molecular Formula | C₁₅H₁₀N₂O₂ |
| HS Code | 2929.10 |
| Synonyms | MDI, PMDI (polymeric MDI), Diphenylmethane-4,4'-diisocyanate, Methylene diphenyl isocyanate |
SECTION 19: SUMMARY TABLE
| Parameter | Monomeric MDI | Polymeric MDI | Modified MDI |
|---|---|---|---|
| Product | Monomeric MDI | Polymeric MDI | Modified MDI |
| CAS Number | 101-68-8 | 26447-40-5 | Variable |
| Molecular Formula | C₁₅H₁₀N₂O₂ | Oligomer mixture | Variable |
| Molecular Weight | 250.26 g/mol | Variable | Variable |
| Appearance (25°C) | White to pale yellow solid/molten liquid | Brownish-yellow liquid | Light yellow liquid |
| Functionality | 2.0 | 2.3 – 3.0 | 2.0 – 2.5 |
| %NCO Content | ~33.6 | 30 – 32 | 28 – 32 |
| Freezing Point | ~38 – 40°C | <0°C | <0°C |
| Viscosity (25°C) | 5 – 15 mPa·s (molten) | 150 – 300 mPa·s | 20 – 200 mPa·s |
| Primary Function | Polymerization, elastomers, adhesives | Foams, insulation, panels | Coatings, adhesives, specialty applications |
| Shelf Life | 6 – 12 months (under N₂) | 6 – 12 months | 6 – 12 months |
| GHS Signal Word | DANGER | DANGER | DANGER |
| UN Number | UN 2489 / UN 2209 | UN 2489 / UN 2209 | UN 2489 / UN 2209 |
| Special Properties | High purity; Solid at room temperature | Liquid at room temperature; Higher functionality | Liquid; Low freezing point |
SECTION 20: CRITICAL WARNINGS AND BEST PRACTICES
CRITICAL WARNINGS:
Respiratory sensitizer (H334) – May cause asthma-like symptoms, breathing difficulties. Sensitized individuals may react at very low concentrations.
Skin sensitizer (H317) – May cause allergic contact dermatitis. Avoid skin contact.
Causes serious eye damage (H318). Wear eye protection. In case of eye contact, rinse with plenty of water and seek immediate medical attention.
Reacts violently with water – Releases CO₂ gas and forms polyurea. May cause pressure build-up in containers. Protect from moisture.
Corrosive – Causes serious damage to skin and eyes.
Toxic fumes – When heated or in fire, toxic isocyanate vapors are released.
Incompatibilities: Water (violent reaction), alcohols (urethane formation), amines (urea formation), strong bases (exothermic), acids, oxidizing agents.
Hygiene Requirement: Wash hands thoroughly after handling. Contaminated clothing should not be allowed out of the workplace. Do not eat, drink, or smoke while using.
Sensitization risk: Repeated exposures may lead to sensitization; Exposure records must be kept and medical surveillance provided.
BEST PRACTICE RECOMMENDATIONS:
Foam Production: React MDI with polyols to produce flexible or rigid polyurethane foam; Use water or blowing agents to generate CO₂ gas for cellular structure; Temperature control is critical (exothermic reaction); Flexible foams: furniture, bedding, automotive; Rigid foams: insulation, panels, refrigerators.
Adhesive and Binder Use: React MDI with active hydrogen groups on surfaces to form strong chemical bonds; Use as adhesive for wood, metal, plastic, and composite materials; Acts as binder in wood composites (OSB, MDF); Avoid moisture during application.
Coating and Sealant: React MDI with polyols to form durable, flexible, and chemical-resistant coatings; Used in floor coatings, industrial coatings, and sealants; Ensure good ventilation during application; Pay attention to curing time.
Elastomer Production: React MDI with long-chain polyols to form flexible, durable elastomers; Used in wheels, rollers, seals, and vibration-damping components; Hardness and flexibility depend on polyol type.
Handling: Use in well-ventilated areas; Avoid inhalation of vapors; Use closed systems; Local exhaust ventilation is required; Protect from moisture; Wear appropriate PPE.
Personal Protective Equipment: Chemical-resistant gloves (nitrile, neoprene, butyl – at least 0.4 mm), chemical splash goggles (face shield recommended), protective clothing (chemical-resistant, full-body), NIOSH-approved isocyanate cartridge respirator (organic vapor + particulate), safety shower and eyewash station nearby.
Hygiene: Wash hands thoroughly after handling; Do not eat, drink, or smoke while using; Remove contaminated clothing and wash before reuse; Shower after handling; Maintain exposure records.
Storage: Store in tightly closed, moisture-proof containers (stainless steel, suitable polyethylene); Store under dry inert gas (N₂); Monomeric MDI: 40-50°C molten or solid; Polymeric MDI: 10-35°C; Protect from moisture and incompatible materials; Keep containers tightly closed; Shelf life: 6-12 months under proper conditions.
Spill Management: Evacuate area; Wear full protective equipment; Ventilate area; Contain spill with inert absorbent material (sand, vermiculite); Avoid contact with water (exothermic reaction); Prevent from entering drains or waterways; Collect and place in suitable sealed container; Dispose of as hazardous waste.
Disposal: Dispose of in accordance with local, regional, and national regulations; MDI waste is considered hazardous waste; Unreacted MDI must be disposed of in specialized incineration facilities; Neutralization (with alcohol or amine) may be performed; Do not discharge to sewers.
SPECIAL NOTE ON RIGID POLYURETHANE FOAM (INSULATION):
Polymeric MDI (PMDI) is the preferred isocyanate for rigid polyurethane foam production:
Functionality: PMDI (f=2.3-3.0) provides higher crosslinking → Rigid, closed-cell structure
Blowing Agents: Water (CO₂), physical blowing agents (pentane, HFCs)
Applications: Building insulation, sandwich panels, refrigeration, refrigerators, thermal insulation
Temperature: Reaction is exothermic; Temperature control is critical
Advantages: High thermal insulation performance, lightweight, durable
SPECIAL NOTE ON FLEXIBLE POLYURETHANE FOAM:
Monomeric MDI or PMDI blends are used in flexible foam production:
Functionality: Lower functionality (f=2-2.5) → Less crosslinking → Flexible structure
Blowing Agent: Water (CO₂) is the primary blowing agent
Applications: Furniture, bedding, automotive seating, sponges
Reactivity: Controlled by polyol type and catalysts
Advantages: High elasticity, comfort, durability
SPECIAL NOTE ON SENSITIZATION:
MDI is a strong respiratory and skin sensitizer:
Mechanism: Isocyanate groups react with body proteins to cause allergic response
Respiratory Sensitization: Asthma-like symptoms, wheezing, shortness of breath, coughing; Sensitized individuals may react at very low concentrations (<0.001 ppm)
Skin Sensitization: Allergic contact dermatitis, redness, itching, blisters
Prevention: Minimize exposure (engineering controls, PPE); Regular medical surveillance; Exposure records; Sensitized personnel should avoid working with MDI
Chronic Effects: Repeated exposure may lead to permanent asthma development
LEGAL DISCLAIMER:
The information provided in this document is based on our current knowledge and experience and is presented in good faith. However, as all conditions of use are beyond our control, it does not constitute a binding specification or warranty. This Technical Data Sheet is for informational purposes only. Users are responsible for testing the suitability for their own applications. For complete safety, storage, use, handling, waste, and regulatory compliance information, please refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. MDI is a respiratory and skin sensitizer; appropriate engineering controls and personal protective equipment are mandatory.