Purified terephthalic acid: Characteristics
Why a few ppm of 4-CBA matter so much
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.PTA is sold on purity, especially 4-CBA and p-toluic acid levels, and on particle size, which matter for polymer colour and slurry handling.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| 4-CBA content | typically below 25 ppm (indicative) | Chain terminator; affects polymer colour and viscosity | indicative |
| Particle size | about 100-150 microns average (indicative) | Slurry handling with MEG | indicative |
| Colour (b value) | low | White polyester | indicative |
Commercial grades
- Fibre grade PTA
- Bottle grade PTA (often with isophthalic acid)
- Medium-purity TA for some fibres