• Isophthalic acid is an aromatic dicarboxylic acid, it is a colorless crystalline solid.
• It is used as an intermediate primarily for unsaturated polyester resins and alkyd and polyester coating resins.
• It is used primarily as a component of PET (polyethylene terephthalate) copolymer, which is used in bottle resins and, to a much lesser extent, for fibers.
• Its other applications include use in aramid fibers, as a component of co-polyester resins and in high-temperature polymer.