PhNCO

PhNCO, short for phenyl isocyanate, is an organic compound with the formula C7H5NO. It consists of a phenyl group attached to an isocyanate functional group (-N=C=O). In its pure form it is typically a colorless to pale yellow liquid with a sharp, acrid odor. It is reactive toward moisture and various nucleophiles and is typically handled under dry, inert conditions to prevent hydrolysis and polymerization.

Applications and uses

PhNCO is primarily used as a reactive monomer in the production of polyurethanes and related polymers. It serves as a building block for polyurethane foams, coatings, and adhesives and appears as an intermediate in organic synthesis. Its reactivity allows it to form urethane linkages when reacted with alcohols or amines.

Synthesis

Industrial production of phenyl isocyanate commonly involves phosgenation of aniline, a process that converts the amine to the isocyanate under controlled conditions with phosgene byproducts. Alternative routes exist that convert carbamates or related precursors to isocyanates, depending on process economics and safety considerations.

Handling and safety

Isocyanates are known irritants and potential respiratory sensitizers. Exposure can irritate the skin, eyes, and respiratory tract, and repeated exposure may contribute to asthma. PhNCO reacts with water to yield aniline and carbon dioxide, so moisture control is essential. Handling occurs in well-ventilated spaces with appropriate personal protective equipment, including gloves and eye protection. Containers are kept tightly closed and stored under inert conditions to minimize moisture exposure and polymerization.

Environmental considerations

Isocyanates can be reactive and hazardous to the environment if released in large quantities. Spills should be contained and disposed of as hazardous material according to relevant regulations.

See also

Isocyanate; polyurethane; aniline; diisocyanate.