Isocyanates, organic

Organic isocyanates are generally characterized with respect to NCO content. A number of spectroscopic and chemical methods for isocyanate deterrnination are available (96). 

The use of an organic isocyanate instead of potassium isocyanate gives a A-substituted hydantoin. 

Molecular weights of poly(propylene oxide) polymers of greater than 100,000 are prepared from catalysts containing FeCl (40,41). The molecular weight of these polymers is gready increased by the addition of small amounts of organic isocyanates (42). Homopolymers of propylene oxide are also prepared by catalysis using diethylzinc—water (43), diphenylzinc—water (44), and trialkyl aluminum (45,46) systems. 

An organic isocyanate (MDI or a pre-polymer) with a hydroxy compound. The isocyanates are potent respiratory sensitizers, the risk increasing with volatility... 

Organic isocyanates in air Lab method with sampling either onto coated glass-fibre filters followed by solvent desorption, or into impingers and analysis using high performance liquid chromatography 25/3... 

Vinyl chloride in air Organic isocyanates in air Ethylene oxide m air... 

Group of plastics produced by the condensation of organic isocyanates with other plastics. Examples are the urethane plastics. 

Group of plastics composed of resins derived from the condensation of organic isocyanates with compounds containing hydroxyl groups. 

See related cyano compounds, organic isocyanates See other allyl compounds... 

See entry thermochemistry and exothermic decomposition (reference 2) See other organic isocyanates... 

Organic isocyanates (R-N=C=0) are xenobiotics used extensively in the manufacture of paints, pesticides, and polyurethanes. The reactivity of the isocyanate group can also underlie the toxic reactions observed in patients that have been exposed to organic isocyanate monomers. Furthermore, the isocyanates formed in the body can be metabolites of various other xenobiotics, such as ... 

The toxicity of organic isocyanates can be ascribed to two main mechanisms, namely ... 

Fig. 11.11. Mechanism postulated for hydrolysis of organic isocyanates involving electrophilic addition of H20 with general base catalysis. The product of hydration is a carbamic acid that spontaneously decomposes to the primary amine with loss of C02 [117].

Compound CF3SNCO undergoes further reactions typical of organic isocyanates with hydrogen halides (41), amines (28), and other species (39, 69), as is shown in Table II. 

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