4,4'-methylenedianilinium dichloride

Chemical Properties

4,4’-Diaminodiphenylmethane is a pale yel- low crystalline solid (turns light brown on contact with air) with a faint amine-like odor.

Uses

In 1987, about 600 million lb of MDA was produced in the United States captively as a chemical intermediate; additional amounts were also imported. Approximately 99% of theMDAand polymericMDAproduced in the United States, usually by the acid-catalyzed reaction of aniline with formaldehyde, is used as a chemical intermediate in the closedsystem production of methylene diisocyanate (MDI) and polymeric MDI, which are used extensively in the manufacture of rigid semiflexible polyurethane foams for automobile safety cushioning, and also in the production of wire coatings. MDA is also used as a hardener or curing agent for epoxy resins (providing cross-linkages), in the manufacture of various natural and synthetic rubbers as an antioxidant, in the production of polyurethane elastomers, as a curing agent for neoprene, as an antioxidant in rubber, in the preparation of polyamide–imide resins, as a metal deactivator fuel additive (neutralizes the catalytic effect of copper associated with fuel oxidation), and in the production of polymers for synthetic fibers in the textile industry.

General Description

Light beige fine powder.

Air & Water Reactions

May be sensitive to prolonged exposure to air and light. Water soluble.

Reactivity Profile

In aqueous solution behaves as an acid. Materials in this group are generally soluble in water. The resulting solutions contain moderate concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. Many of these compounds catalyze organic reactions.

Fire Hazard

Flash point data for 4,4'-methylenedianilinium dichloride are not available; however, 4,4'-methylenedianilinium dichloride is probably combustible.

Safety Profile

Confirmed carcinogen with experimental carcinogenic and neoplastigenic data. Mutation data reported. When heated to decomposition it emits toxic fumes of NOx and HCl.

Potential Exposure

Used as an intermediate and as a curing agent. Approximately 99% of the DDM produced is con- sumed in its crude form (occasionally containing not more than 50% DDM and ply-DDM) at its production site by reac- tion with phosgene in the preparation of isocyanates and poly- isocyanates. These isocyanates and polyisocyanates are employed in the manufacture of rigid polyurethane foams which find application as thermal insulation. Polyisocyanates are also used in the preparation of the semiflexible polyure- thane foams used for automotive safety cushioning. DDM is also used as: an epoxy hardening agent; a raw material in the production of polyurethane elastomers; in the rubber industry as a curative for Neoprene and as an antifrosting agent (anti- oxidant) in footwear; a raw material in the production of Quana nylon; and a raw material in the preparation of poly (amide-imide) resins (used in magnet wire enamels).

Shipping

UN2651 4,40 -Diaminodiphenyl methane, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Incompatibilities

Dust forms and explosive mixture with air. May polymerize in temperatures .125℃ . A weak base. Incompatible with strong oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong acids. Flammable gas- eous hydrogen may be generated in combination with strong reducing agents, such as hydrides .

Waste Disposal

Controlled incineration (oxides of nitrogen are removed from the effluent gas by scrubbers and/or thermal devices).

Raw materials

Preparation Products