Mondur MA 2903 is an isocyanate-terminated (MDI) prepolymer based on allophanate modified 4,4’-diphenylmethane-diisocyanate (MDI).
Product description
Applications
Mondur MA 2903 can be used as a raw material in the formation of elastomers, microcellular shoe soles, integral skin and semi-flexible urethane foams. As with any product, use of Mondur MA 2903 in a given application must be tested (including but not limited to field testing) in advance by the user to determine suitability. Material has a high propensity to become turbid over time. Turbity shall not be a cause for material rejection by the customer.
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Appearance | Light yellow to yellow; clear to slightly turbid liquid | |||
| Specific gravity | at 25°C | 1,19 | ||
| Flash point | PMCC | > 93 | °C | |
| Viscosity | at 25°C | 400 | mPa•s |
Storage
Mondur MA 2903 prepolymer must be stored in tightly closed containers and protected from contamination with moisture and foreign materials, which can adversely affect processing. It will react slowly with water to form ureas and carbon dioxide gas, which may cause sealed containers to expand and rupture. Partially filled containers should be blanketed with dry nitrogen. Recommended storage temperatures should be maintained between 24° to 38°C (75° to 100°F). Within this range, a storage temperature of about 25°C (77°F) will maximize the storage life of this product. Mondur MA 2903 prepolymer must not be allowed to freeze. Exposure to temperatures less than 15°C (59°F), even for short periods of time, can result in the formation of solid material. During the winter months, appropriate precautions must be taken during shipment and storage. Prolonged storage of solid or partially solid Mondur MA 2903 prepolymer may result in the formation of MDI dimer in amounts which exceed its solubility in the product at normal storage temepratures. This can make the product unusable. If solids should form because of exposure to low temperatures, it may be possible to reliquify Mondur MA 2903 by heating. Use a well-ventilated oven for the minimum time necessary to render it clear. The temperature of the product should not exceed 60°C (140°F). Agitation or drum rollers are recommended to avoid excessive local heating, which will degrade the product.Significant amounts of MDI dimer may form during the heating process. As a result, the remelted diisocyanate may be cloudy, and the processing behavior and/or properties of the final product may be affected. Mondur allophanate modified diisocyanates may show a noticeable color increase during the shelf-life of the product. This is normal behavior for this material and this changes should not impact overall product performance. Following the recommended storage temperature, as stated on the technical data sheet, and minimizing the storage time will minimize the color increase.The shelf life is six months after receipt of material by customer, when stored in sealed original containers under conditions stated above.
Health and Safety Information
Before working with this product, you must read and become familiar with the available information on its risks, proper use, and handling. Information is available in several forms, e.g., in particular in the currently valid safety data sheets and product labels. For further information contact your Covestro representative.
Disclaimer
Contact
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