RIANOX 245
An asymmetric hindered phenolic primary antioxidant with low odor, very low volatility, and excellent resistance to extraction from polymer compounds. Particularly effective in styrene polymers, POM, and polyurethane systems. Also serves as an effective chain terminator during PVC polymerization. Especially noteworthy in synergistic blends with RIANOX® 168 phosphite (RIANOX B-blends).
| CAS No. | 36443-68-2 |
| Chemical Name | Triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] |
| Molecular Weight | 587 |
| Melting Range (°C) | 77–81 |
| Appearance | White / Off-white Powder or Granule |
| Odor | Low Odor |
| Standard Packaging | 20 kg Bag |
| Solvent | Solubility |
|---|---|
| Acetone | ≥50 |
| Chloroform | ≥40 |
| Methylene Chloride | ≥40 |
| Ethyl Acetate | 37 |
| Benzene | 18 |
| Methanol | 12 |
| Ethanol | 10 |
| Toluene | 6 |
| Styrene | 6 |
| n-Hexane | <0.1 |
| Water | <0.01 |
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Where RIANOX 245 fits
RIANOX 245 is an asymmetric hindered phenol (molecular weight 587, melting range 77–81 °C). It combines low odour, very low volatility and good resistance to extraction, and it is particularly effective in styrenic polymers, POM and polyurethane, where general-purpose phenols are less suited. Typical uses:
- Polystyrene, HIPS and ABS
- POM (acetal) compounds
- Polyurethane systems
- Blends with RIANOX 168 phosphite for processing stability
Typical use levels
- Styrenics: 0.1–0.3%, usually with RIANOX 168
- POM: 0.2–0.5%
- Polyurethane: 0.1–0.5%
These are starting points. Confirm the level with multiple-pass extrusion (melt flow retention and colour) and oven ageing on your own compound.
Choosing a phenolic antioxidant
How RIANOX 245 compares with the other hindered phenols we supply:
| Grade | Structure | Mol. weight | Melting point | Best known for |
|---|---|---|---|---|
| RIANOX 1010 | Tetrafunctional phenol | 1178 | 110–125 °C | General-purpose long-term heat stability |
| RIANOX 1076 | Monofunctional, C18 chain | 531 | 50–55 °C | Compatibility and low colour in polyolefins |
| RIANOX 3114 | Isocyanurate trisphenol | 784 | 218–223 °C | Very low volatility, extraction resistance |
| RIANOX 1790 | Isocyanurate trisphenol | 700 | 155–165 °C | Low colour and gas-fade resistance; fibers |
| RIANOX 245 | Asymmetric phenol | 587 | 77–81 °C | Styrenics, POM and polyurethane |
Pairing RIANOX 245 with co-stabilizers
A phenolic antioxidant traps free radicals but does not remove the hydroperoxides formed during melt processing. Pair RIANOX 245 with RIANOX 168 phosphite for processing stability and colour, and with RIANOX DSTP thioester for long-term heat ageing. For outdoor parts, add a HALS light stabilizer, and keep thioesters low when you do, because their acidic by-products weaken HALS. Our HALS UV stabilizer guide explains why.
TDS, documents and samples
The full TDS, COA and SDS for RIANOX 245 are sent by email with the quotation, together with the producer’s REACH and food-contact declarations where applicable. Samples are available for qualification trials. Request the TDS and a quote, or compare the full antioxidants and HALS range.