Phthalic anhydride

Performance and use

Phthalic anhydride, abbreviated as phthalic anhydride, white scaly or crystalline powder, molecular formula C8H403, molecular weight 148.12, melting point 131.1l ° C, boiling point 284.5 ° C, flash point 151 ° C (closed), 165 ° C (opening), self-ignition point 584 ° C , density (solid) 1.527g / cm3, difficult to dissolve in cold water, soluble in hot water, ethanol, ether, benzene and other organic solvents. Phthalic anhydride is a cyclic anhydride formed by dehydration of phthalic acid in the molecule, and is an important raw material in chemical industry, especially for the manufacture of plasticizers. Dibutyl phthalate and dioctyl phthalate are important plasticizers. Polycondensation of phthalic anhydride with polyols (such as glycerin, pentaerythritol) to form polyarylate resin for the paint industry; if polycondensed with ethylene glycol and unsaturated acid, it produces unsaturated polyester resin, which can be used to make insulating varnish and glass. Fiber reinforced plastic. Phthalic anhydride is also a raw material for the synthesis of benzoic acid and terephthalic acid, and is also used for drug synthesis.

Technical indicators