paratoluene

Paratoluene, also known as 4-methyltoluene or p-xylene, is an aromatic hydrocarbon with the chemical formula C8H10. It is one of the three positional isomers of xylene, the others being ortho-xylene and meta-xylene. Paratoluene is a colorless, flammable liquid with a sweet, aromatic odor. It is a constituent of coal tar and petroleum.

Industrially, paratoluene is primarily produced through the catalytic reforming of petroleum naphtha. It is a key intermediate in the production of terephthalic acid (TPA) and dimethyl terephthalate (DMT), which are essential monomers for the manufacturing of polyethylene terephthalate (PET) plastics. PET is widely used in bottles, films, and synthetic fibers. Paratoluene is also used as a solvent in various industrial applications, including paints, varnishes, and printing inks.

The physical properties of paratoluene include a melting point of 13.2 °C and a boiling point of 138.4 °C. It is sparingly soluble in water but miscible with most organic solvents. Like other aromatic hydrocarbons, paratoluene is combustible and can form explosive mixtures with air. Exposure to high concentrations of paratoluene vapor can cause irritation to the eyes, skin, and respiratory system, and may lead to central nervous system depression. It is classified as a volatile organic compound (VOC).