High-temperature color
Keeps color and melt flow stable at high processing temperatures.
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.

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.
Typical specification. Every shipment is supplied with a batch COA; the limits that apply to your order are confirmed in the quotation and contract.
Keeps color and melt flow stable at high processing temperatures.
Stays active and free-flowing in humid storage, unlike many diphosphites.
High phosphorus efficiency often allows lower loading than standard phosphites.
Typical specification. Every shipment is supplied with a batch COA; the limits that apply to your order are confirmed in the quotation and contract.
| 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% |
Pick an application to see how 9228 is normally used and what to confirm before your trial.

Processing stabilizer for PP and PE film, fiber and thin-wall molding, with a phenolic antioxidant.
Color and melt stability at the high temperatures these polymers need.
Used with an amide phenolic such as 1098 for processing color in nylon.
25 kg net bags or cartons with a PE inner liner. Palletized; private-label packing on request.
Keep sealed in a cool, dry, ventilated place away from heat and direct sun. See the SDS for full handling details.
Typically 3–15 business days from order confirmation, depending on quantity. FOB, CIF or DAP to major ports.
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.
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.
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.
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.
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 |
Hydrolysis-resistant phosphite secondary antioxidant for color and melt-flow protection during processing.
View product →Pentaerythritol diphosphite for color and melt stability in polyolefins and styrenics.
View product →High-MW hindered phenolic primary antioxidant for long-term thermal protection with low volatility.
View product →Amide-type phenolic antioxidant built for polyamides and fiber, with good color during processing.
View product →When processing temperature, multiple passes or color requirements push 168 to its limit, or when you need lower total loading.
No. It is a white powder with a melting point of at least 225 °C.
Yes. Like all phosphites it protects mainly during processing; use it with a phenolic primary for long-term protection.
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.
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.
Send your application, specification and quantity to request a quotation or supporting documents.