Terephthalic Acid, Benzene Dicarboxylic Acid, PTA, TPA, BDC, 100-21-0

Terephthalic Acid, Benzene Dicarboxylic Acid, PTA, TPA, BDC, 100-21-0

Chemical and Physical Properties

• Chemical Formula: C₆H₄(CO₂H)₂

• CAS Number: 100-21-0

• Molecular Weight: 166.13 g/mol

• Appearance: White crystalline powder

• Density: 1.522 g/cm³

• Melting Point: 427°C (under closed conditions)

• Boiling Point: Undergoes thermal decomposition

• Solubility: Poor solubility in water (0.0015 g/100 mL at 20°C); dissolves in polar organic solvents

• Acidity (pKa): 3.51, 4.82

• Magnetic Susceptibility: -83.51 × 10⁻⁶ cm³/mol

Production Process

Terephthalic acid is industrially produced through the oxidation of p-xylene using the liquid-phase oxidation method:

1. Raw Material: p-Xylene (C₆H₄(CH₃)₂)

2. Solvent: Dissolved in acetic acid

3. Catalyst: Cobalt and manganese acetate with bromide

4. Oxidation: Reacts with air or pure oxygen to form terephthalic acid

5. Purification: Crystallization and filtration to achieve high purity

Applications

• Polyethylene Terephthalate (PET) Production: Used in plastic bottles, textile fibers, and packaging films

• Polybutylene Terephthalate (PBT) Production: Engineering plastics and specialty polymers

• Plasticizers: Used in the production of dioctyl terephthalate (DOTP)

• Paints and Coatings: Polyester coating resins for automotive and industrial applications

• Pharmaceutical Industry: Used in certain drug formulations

• Smoke Bombs: Found in military-grade smoke grenades like M83 and M90

Other Names

• TPA (Terephthalic Acid)

• PTA (Purified Terephthalic Acid)

• p-Phthalic Acid

• 1,4-Benzenedicarboxylic Acid

• BDC (Benzenedicarboxylic Acid)