Terephthalic acid

CAS: 100-21-0

Overview

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.

Its role as a building block in high-volume polymer synthesis makes it one of the most traded industrial organic acids globally. This chemical is the foundational raw material for polyethylene terephthalate.

It is consumed in enormous volumes for beverage bottles, food packaging films, and textile-grade polyester fiber. In engineering plastics, it contributes to polybutylene terephthalate formulations.

These formulations are used in automotive and electrical components. Coatings and adhesives manufacturers use the acid as a crosslinking monomer in alkyd and powder coating resins.

Controlled molecular architecture is critical to end-product performance in these sectors. Specialty applications include use as a catalyst precursor and pH-buffering agent in select industrial process formulations.

The material is supplied as a white powder or fine crystalline solid. Purified terephthalic acid is the dominant commercial specification for polymer-grade applications in the global market.

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 for industrial logistics.

This reflects its high-volume commodity status across the chemical supply chain. All batches are tested to ensure they meet rigorous industrial and chemical manufacturing requirements.

Physical Properties

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℃

Safety & Handling

Warning GHS07 GHS08 Hazard Statements H302 Harmful if swallowed H315 Causes skin irritation H316 Causes mild skin irritation H319 Causes serious eye irritation H320 Causes eye irritation H335 May cause respiratory irritation H361 Suspected of damaging fertility or the unborn child H372 Causes damage to organs through prolonged or repeated exposure H373 May causes damage to organs through prolonged or repeated exposure 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. P270 Do not eat, drink or smoke when using this product. P271 Use only outdoors or in a well-ventilated area. P280 Wear protective gloves/protective clothing/eye protection/face protection. P318 IF exposed or concerned, get medical advice. P319 Get medical advice/attention if you feel unwell. P321 Specific treatment (see … on this label). P330 Rinse mouth. P405 Store locked up. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P301+P317 Get emergency medical help. P302+P352 IF ON SKIN: Wash with plenty of water. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P332+P317 Get emergency medical help. P337+P317 If eye irritation persists: Get medical advice/attention. Get emergency medical help. P362+P364 Take off contaminated clothing and wash it before reuse. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code	29173990
Storage Class	11 - Combustible Solids
WGK (Germany)	3

Other Names

Industries

Food & Nutrition Personal Care & Cosmetics Textile, Leather & Paper Printing & Packaging Plastics & Polymers