Acrylic acid: Characteristics
Ester grade versus glacial: why purity splits markets
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.Two grades dominate: crude (ester grade) for making esters and glacial for SAP and polymers. Inhibitor content, dimer formation and freezing point drive storage and handling.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Purity | glacial AA at least 99.5%; ester-grade crude about 98% (indicative) | SAP needs low aldehydes and dimer. | industry standard (indicative) |
| Freezing point | 13°C | Must be kept warm, but not too warm, to prevent polymerisation. | standard physical data |
| Inhibitor | about 200 ppm MEHQ (hydroquinone monomethyl ether), needs dissolved oxygen | Prevents runaway polymerisation. | industry standard (indicative) |
| Dimer formation | diacrylic acid forms during storage | Limits shelf life to weeks or months. | industry standard |
Commercial grades
- Glacial acrylic acid (GAA)
- Crude/ester-grade acrylic acid
- Acrylate esters: n-butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, methyl acrylate
- SAP