Terephthalic acid
CAS Number
100-21-0
EC Number
202-830-0
Abbreviation
PTA
What is Terephthalic acid?
Terephthalic acid (CAS 100-21-0), commonly abbreviated as PTA in commodity markets, is a dicarboxylic acid that serves as a primary monomer in the production of polyester resins and fibers.
Where is Terephthalic acid used?
- Polyester resins and fibers: foundational raw material for polyethylene terephthalate
- Beverage bottles, food packaging films, and textile-grade polyester fiber
- Engineering plastics: contributes to polybutylene terephthalate formulations for automotive and electrical components
- Coatings and adhesives: crosslinking monomer in alkyd and powder coating resins
- Specialty applications include use as a catalyst precursor and pH-buffering agent in select industrial process formulations.
Commercial specifications
- Purified terephthalic acid is the dominant commercial specification for polymer-grade applications
- Technical and industrial grades are available for non-fiber and non-packaging end uses
- Packaging options typically range from multi-wall bags to bulk supersacks
Other Names (Synonyms)
para-phthalic acid|para-benzenedicarboxylic acid|P-Phthelic acid|p-phthalic acid|p-dicarboxybenzene|p-benzenedicarboxylic acid|benzene-p-dicarboxylic acid|benzene-1,4-dicarboxylic acid|PTA
What are the physical properties of Terephthalic acid?
Melting Point 402 °C (sublm)
Boiling Point 214.32°C (rough estimate)
Density 1.51 g/cm³
Flash Point 260°C
Appearance TPA is a white crystalline solid.
Color White
Form Crystalline Powder
Water Solubility slightly soluble in water (0,017 g/L at 25°C)
Vapor Pressure <0.01 mm Hg ( 20 °C)
Refractive Index 1.5100 (estimate)
pH 3.36(1 mM solution);2.79(10 mM solution);2.26(100 mM solution)
Log P 2 at 25℃
How is Terephthalic acid classified and handled safely? Learn More
Warning
GHS07· Irritant GHS08· Health Hazard
Hazard Statements
H302 Harmful if swallowed
H315 Causes skin irritation
H316 Causes mild skin irritation
H319 Causes serious eye irritation
Precautionary Statements
P203 Obtain, consult and follow expert instructions for use.
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
P264 Wash … thoroughly after handling.
Which trade and regulatory codes apply to Terephthalic acid?
HS Code 29173990
Storage Class 11 - Combustible Solids
WGK (Germany) 3