High-temperature color
Keeps color and melt flow stable at high processing temperatures.
SUNNOX® 9228
Antioxidant 9228 High-Performance Phosphite Supplier
SUNNOX® 9228 is a high-performance diphosphite secondary antioxidant. It gives excellent color and melt stability at high processing temperatures with very good hydrolysis resistance and low volatility.
CAS 154862-43-8 · Diphosphite · Secondary antioxidant
- Lot COA with every shipment
- Samples for your trials
- Technical support for your trial
Product overview & key benefits
Antioxidant 9228 (bis(2,4-dicumylphenyl) pentaerythritol diphosphite) is a solid white powder with a molecular weight of about 853 and a melting point of at least 225 °C. Its high phosphorus efficiency and hydrolysis resistance make it a step up from 168 for demanding processing such as thin-wall molding, film, fiber and engineering plastics, used together with a phenolic primary.
Hydrolysis resistant
Stays active and free-flowing in humid storage, unlike many diphosphites.
Efficient
High phosphorus efficiency often allows lower loading than standard phosphites.
Technical specifications
| Parameter | Typical value |
|---|---|
| Product Name | Antioxidant 9228 |
| Brand | SUNNOX® 9228 |
| CAS No. | 154862-43-8 |
| Chemical Name | Bis(2,4-dicumylphenyl) pentaerythritol diphosphite |
| Molecular Formula | C53H58O6P2 |
| Molecular Weight | 853.0 |
| Appearance | White powder |
| Melting Point | ≥225 °C |
| Volatile Matter | ≤0.5% |
Typical specification. Every shipment is supplied with a batch COA; the limits that apply to your order are confirmed in the quotation and contract.
Applications by Polymer
Pick an application to see how 9228 is normally used and what to confirm before your trial.
Polyolefins
Processing stabilizer for PP and PE film, fiber and thin-wall molding, with a phenolic antioxidant.
Check before trial
- Resin grade and process (film, fiber, molding, pipe)
- Processing temperature and number of passes
- Current antioxidant package and dosage
PC, PET & Engineering Plastics
Color and melt stability at the high temperatures these polymers need.
Check before trial
- Polymer type
- Processing temperature
- Color target
Polyamide
Used with an amide phenolic such as 1098 for processing color in nylon.
Check before trial
- PA type and filler
- Processing temperature
- Color target
Selection & comparison
Selecting an Antioxidant System
| Your requirement | What usually works |
|---|---|
| Color and melt-flow stability during extrusion or molding | Phosphite secondary antioxidant (168) with a phenolic primary |
| Long-term heat aging in service | High-MW phenolic primary (1010), often with a thioester (DLTDP / DSTDP) |
| Thin film, fiber, low-melting compounding | Lower-melting phenolic (1076) for easy dispersion |
| Repeated processing / recycled content | Raise the phosphite share in the blend and check yellowing after each pass |
| Humid storage or long transit | Hydrolysis-resistant phosphite such as 168; keep bags sealed |
| Food-contact articles | Ask for the grade-specific food-contact statement before trials |
| Replacing an existing grade | Send your current TDS or COA; we match on the parameters you approve |
Antioxidant Comparison
Swipe or scroll horizontally to see all columns →
| Product | Type | Mol. weight | Melting point | Main job | Typical starting level* |
|---|---|---|---|---|---|
| SUNNOX® 9228 | Diphosphite · secondary | 853.0 | ≥225 °C | High-temperature processing, hydrolysis resistance | 0.05–0.2% with a phenolic |
| SUNNOX® 168 | Phosphite · secondary | 646.9 | 183–187 °C | Processing stability, color | 0.05–0.2% with a phenolic |
| SUNNOX® PEP-36 | Diphosphite · secondary | 632.7 | ≥235 °C | Color and melt stability | 0.05–0.2% with a phenolic |
| SUNNOX® 1010 | Hindered phenol · primary | 1177.6 | 110–125 °C | Long-term thermal protection | 0.05–0.3% |
| SUNNOX® 1098 | Hindered phenol · amide | 636.9 | 156–161 °C | Polyamide and fiber stabilization | 0.1–0.5% |
*Starting points for trials, not fixed recommendations. The right level depends on resin, catalyst residue, processing temperature and service life. Primary and secondary antioxidants do different jobs and are not interchangeable.
Packaging & storage
Packaging
25 kg net bags or cartons with a PE inner liner. Palletized; private-label packing on request.
Storage
Keep sealed in a cool, dry, ventilated place away from heat and direct sun. See the SDS for full handling details.
Lead time & terms
Typically 3–15 business days from order confirmation, depending on quantity. FOB, CIF or DAP to major ports.
From first email to approved supply
Name the failure you want to prevent
Yellowing or melt-flow change during processing points to the phosphite share; embrittlement or cracking after months in service points to the phenolic and thioester share. Note recycled content and the number of extrusion passes.
Start from a proven blend
Most polyolefin packages start from a phenolic primary plus a phosphite secondary, then adjust. Send your current package and we suggest a starting blend for the trial instead of changing several variables at once.
Compare the numbers that matter
For powders: assay, melting range, volatiles and light transmittance at 425/500 nm (a direct read on color). Ask for the same parameters on our COA that appear on your incoming-inspection sheet.
Lock in supply terms
Agree packaging, monthly volume, destination port and required documents up front. A matching CAS number alone does not qualify a new source; run your trial and keep the approved lot COA as the reference.
Tell us your requirement. We match the grade.
Start with your polymer, quantity and destination. Add your current grade or specification and we will quote against it.
| Information | Example |
|---|---|
| Polymer / Material | PP, PE, ABS, compound, masterbatch |
| Application | Injection molding, extrusion, film, fiber |
| Current additive | Grade or supplier you use today |
| Required specification | Your TDS, COA or key limits |
| Quantity | Trial order / monthly / annual volume |
| Packaging | Standard 25 kg or specific requirement |
| Destination | Country and port |
| Documents needed | COA, SDS, REACH, food-contact statement |
Related products
SUNNOX® 168
Hydrolysis-resistant phosphite secondary antioxidant for color and melt-flow protection during processing.
View product →SUNNOX® PEP-36
Pentaerythritol diphosphite for color and melt stability in polyolefins and styrenics.
View product →SUNNOX® 1010
High-MW hindered phenolic primary antioxidant for long-term thermal protection with low volatility.
View product →SUNNOX® 1098
Amide-type phenolic antioxidant built for polyamides and fiber, with good color during processing.
View product →Antioxidant 9228 FAQ
When should I upgrade from 168 to 9228?
When processing temperature, multiple passes or color requirements push 168 to its limit, or when you need lower total loading.
Is 9228 a liquid?
No. It is a white powder with a melting point of at least 225 °C.
Does it need a phenolic antioxidant?
Yes. Like all phosphites it protects mainly during processing; use it with a phenolic primary for long-term protection.
Can I get a sample before ordering?
Yes. Tell us the polymer, the test you plan to run and the quantity you need. Samples ship with a COA so you can compare the lot against your current material.
What if a COA does not match our agreed specification?
Send us the agreed specification and the COA showing the difference (parameter, unit and test method). We check it with the production batch record before you accept the material, and replace or re-test where the lot is out of specification.
