Paraxylene (PX) is an important aromatic hydrocarbon with various industrial applications, primarily in the production of purified terephthalic acid (PTA), which is a key precursor for polyester fibers and polyethylene terephthalate (PET). Here are some of its notable properties and uses: Properties of Paraxylene: Melting Point: 12-13 C Boiling Point: 138 C Density: 0.861 g/mL at 20 C Vapor Density: 3.7 (compared to air) Vapor Pressure: 9 mm Hg at 20 C Refractive Index: n20/D 1.495 Flash Point: 77 F Storage Temperature: Recommended at +5C to +30C Solubility: Slightly soluble in water (0.2 g/L) Appearance: Colorless liquid pKa: >15. Applications: PTA Production: Approximately 65% of PTA produced is used to manufacture polyester fibers, which are widely used in clothing and textiles. PET Bottles: About 30% of PTA is converted into PET, commonly used for beverage bottles and packaging. Plastic Products: The remaining 5% is utilized in various plastic products, including films and food containers