Methyl diisocyanate

Methylenebis(4-phenyl isocyanate). This compound is also known as methyl diisocyanate [101-68-8] (MDI) and is produced by the condensation of aniline and formaldehyde with subsequent phosgenation. Its principal end use is rigid urethane foams other end uses include elastic fibers and elastomers. Total formaldehyde use is 5% of production (115). 

Methyl diisocyanate, 1% petrolatum Phenol formaldehyde resin, 1% (adhesives)... 

Example 4 of Reference 8 shows the balance of properties obtained from a range of PU. The polyester solution (Crystic 199) was 38% by weight of styrene and 62% by weight of an unsaturated polyester. The polyurethane was based on 4 4 -diphenyl methyl diisocyanate and oxy-propylated glycerol. The results are shown in Table 8.4. The midrange compositions, samples B, C, and D, offer the best balance of properties and are clearly superior to the unmodified polyester, sample G. The polyurethane alone, F, it should be pointed out, has a Tg near 122 C. 

Urea-formaldehyde resins Phenolb resins Acetylenb chembals Potyacetal resins Methyl diisocyanate Vbyl acetate Acetb anhydride Ethyl acetate... 

Similarly, nitroben2ene, carbon monoxide, and methanol can react sequentially in the presence of noble metal catalysts, to produce methyl A/-phenylcarbamate [2603-10-3] (4). The phenylcarbamate is subsequently coupled with formaldehyde [50-00-0] to yield the methylenebis(carbamate) (5) which is pyroly2ed to yield methylene diphenyl diisocyanate (MDI) (23). 

A convenient method for the synthesis of these low boiling materials consists of the reaction of /V,/V-dimethy1iirea [96-31-1] with toluene diisocyanate to yield an aUphatic—aromatic urea (84). Alternatively, an appropriate aUphatic—aromatic urea can be prepared by the reaction of diphenylcarbamoyl chloride [83-01-2] with methylamine. Thermolysis of either of the mixed ureas produces methyl isocyanate ia high yield (3,85). 

Aliphatic Isocyanates. Aflphatic diisocyanates have traditionally commanded a premium price because the aflphatic amine precursors ate mote expensive than aromatic diamines. They ate most commonly used in appHcafions which support the added cost or where the long-term performance of aromatic isocyanates is unacceptable. Monofuncfional aflphatic isocyanates, such as methyl and -butyl isocyanate, ate used as intermediates in the production of carbamate-based and urea-based insecticides and fungicides (see Fungicides, agricultural Insectcontroltechnology). 

Yield for the process at low catalyst loading is 95%. AJ-Methyl-toluenediamiae, one of the reaction by-products, represents not only a reduction ia yield, but also a highly objectionable impurity ia the manufacture of toluene diisocyanate. Low concentrations of CO (0.3—6% volume) control this side reaction. 

NOTE - Petrochemical plants also generate significant amounts of solid wastes and sludges, some of which may be considered hazardous because of the presence of toxic organics and heavy metals. Spent caustic and other hazardous wastes may be generated in significant quantities examples are distillation residues associated with units handling acetaldehyde, acetonitrile, benzyl chloride, carbon tetrachloride, cumene, phthallic anhydride, nitrobenzene, methyl ethyl pyridine, toluene diisocyanate, trichloroethane, trichloroethylene, perchloro-ethylene, aniline, chlorobenzenes, dimethyl hydrazine, ethylene dibromide, toluenediamine, epichlorohydrin, ethyl chloride, ethylene dichloride, and vinyl chloride. 

To incorporate a labile azo group as the essential active site to MAI, a series of azo compounds such as 2,2 azobisisobutyronitrile (AIBN), 4,4 -azobis(4-cyanopen-tanoyl chloride) (ACPC), 2,2 azobis (2-cyanopropanol) (ACPO), 2,2 azobis [2-methyl-N-(2-hydroxyethyl)prop-ionamide] (AHPA), etc., were used as starting materials for polycondensation with various diols, diamines, diacids, or diisocyanates. 

The Postnitrated Polyurethane Polymer of 3-Nitro-3-Aza-l,5-Pentane Diisocyanate and 2-Nitro-2-Methyl-1,3-Propanediol. 

The Postnitrated Polyurethane Polymer of 3,6-Dinitraza-1,5-Octane Diisocyanate and 2-Methyl-2-Nitro 1,3-Propanedio. n... 

Methyl methacrylate can also be polymerized by radiation using either a cobalt-60 source or accelerated electrons at dose rates up to 3 megarads/sec. The activation energy for the electron beam polymerization is about 7.0kcal/ mole (Ref 12). Radical polymerization can also occur using diisocyanates or hydroperoxides as the initiating species (Ref 15)... 

Another class of hydrocarbon binders used in propints are the carboxy-terminated polybutadiene polymers which are cross-linked with either tris[l-(2-methyl)aziridinyl] phosphine oxide (MAPO) or combinations with phenyl bis [l -(2-methyl)aziridinyl] phosphine oxide (Phenyl MAPO). Phenyl MAPO is a difunctional counterpart of MAPO which makes possible chain extension of polymers with two carboxylic acid groups. A typical propint formulation with ballistic properties is in Table 11 (Ref 83) Another class of composites includes those using hydroxy-terminated polybutadienes cross-linked with toluene diisocyanate as binders. The following simplified equations illustrate typical reactions involved in binder formation... 

Methylene diphenyl diisocyanates (MDIs), 201, 219. See also MDI isomers liquefied, 211, 226-227 Methyl placement, precise versus random, 447... 

II. B polyethylene glycol, ethylene oxide, polystyrene, diisocyanates (urethanes), polyvinylchloride, chloroprene, THF, diglycolide, dilac-tide, <5-valerolactone, substituted e-caprolactones, 4-vinyl anisole, styrene, methyl methacrylate, and vinyl acetate. In addition to these species, many copolymers have been prepared from oligomers of PCL. In particular, a variety of polyester-urethanes have been synthesized from hydroxy-terminated PCL, some of which have achieved commercial status (9). Graft copolymers with acrylic acid, acrylonitrile, and styrene have been prepared using PCL as the backbone polymer (60). 

Methyl palmitate, m269a Methyl pentyl ketone, hi4 Methylphenols, c303 thru c305 Methyl-w-phenylene diisocyanate, tl71... 

Isocyanates n-Butyl isocyanate, methyl isocyanate, toluene diisocyanate... 

Lithium aluminum hydride Lithium hydride Methyl isocyanate Methylaluminum sesquibromide Methylaluminum sesquichloride Methyldichlorosilane Methylene diisocyanate Methylpentaldehyde Methyltrichlorosilane Mono-(trichloro)-tetra-(mono-potassium dichloro)-penta-s-triazinetrione, dry Monochloro-s-triazinetrione acid Octadecyltrichlorosilane Phenyl trichlorosilane Phosphorus oxychloride Phosphorus pentachloride Phosphorus pentasulfide... 

Future work will be concerned with quantitative measurement of hydrogen abstraction rates of labile hydrogens in the carbamate moieties of several aromatic diisocyanate based polyurethanes. It is expected that experimental conditions will alter significantly the hydrogen abstraction rate. Emphasis will also be placed on measurement of transient intermediates in polyurethane films. Finally, extensive laser flash photolysis experiments will be conducted on polyurethanes based on both 2,A-toluenediisocyanate and 2,6-toluenediisocyanate. Preliminary data suggest that the placement of the methyl substituent can alter the nature of the transient intermediates formed. 

Butane-1,4-diisocyanate, 2376 f Butyl isocyanate, 1931 4-Chlorophenyl isocyanate, 2648 1,6-Diisocyanatohexane, 3008 Diisocyanatomethane, 1079 2,4-Diisocyanatotoluene, 3117 f Methyl isocyanate, 0761... 

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