139-25-3 Usage
Description
4,4'-Diisocyanato-3,3'-dimethyldiphenylmethane, also known as MDI, is an organic compound that belongs to the class of diisocyanates. It is a colorless to pale yellow, high molecular weight solid with a strong, pungent odor. MDI is characterized by its reactive isocyanate functional groups, which make it a versatile building block for various applications. It is known for its high reactivity, thermal stability, and resistance to degradation.
Uses
Used in Polyurethane Industry:
4,4'-Diisocyanato-3,3'-dimethyldiphenylmethane is used as a key chemical intermediate for the production of polyurethane materials. It serves as a crucial component in the synthesis of rigid and flexible polyurethane foams, which are widely used in various applications such as insulation materials, furniture, bedding, automotive components, and construction materials. The high reactivity and thermal stability of MDI contribute to the excellent performance and durability of the resulting polyurethane products.
Used in Environmental Monitoring:
4,4'-Diisocyanato-3,3'-dimethyldiphenylmethane is also recognized as an environmental toxin and is listed on the US Environmental Protection Agency (EPA) Toxic Release Inventory (TRI) list. This listing highlights the need for proper handling, storage, and disposal of MDI to minimize its potential impact on human health and the environment. Industries that use MDI in their manufacturing processes are required to report their releases of this chemical to the EPA, allowing for better tracking and management of its environmental risks.
Reactivity Profile
Isocyanates and thioisocyanates, such as 4,4'-DIISOCYANATO-3,3'-DIMETHYLDIPHENYLMETHANE, are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].
Safety Profile
Poison by intravenous
route. A sensitizer. When heated to
decomposition it emits toxic fumes of NOx
and CN-.
Check Digit Verification of cas no
The CAS Registry Mumber 139-25-3 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,3 and 9 respectively; the second part has 2 digits, 2 and 5 respectively.
Calculate Digit Verification of CAS Registry Number 139-25:
(5*1)+(4*3)+(3*9)+(2*2)+(1*5)=53
53 % 10 = 3
So 139-25-3 is a valid CAS Registry Number.
139-25-3Relevant articles and documents
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Bailey et al.
, p. 794,795 (1956)
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METHOD OF PRODUCING MODIFIED ORGANIC POLYISOCYANATE
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, (2008/06/13)
A modified organic polyisocyanate having isocyanurate rings is produced by adding a trimerization catalyst, an organic phosphite, a surfactant and, if desired, a ferrocene compound to an organic polyisocyanate and/or partially urethanated organic polyisocyanate, converting at most 20 % by weight of all of the isocyanate groups into isocyanurate groups, and adding, if necessary, a terminating agent to the reaction system.
