Processing color
Strong protection against yellowing during extrusion and molding.
Antioxidant PEP-36 Phosphite Supplier
SUNNOX® PEP-36 is a pentaerythritol diphosphite secondary antioxidant. It protects color and melt flow during processing of polyolefins, styrenics and engineering plastics, with good hydrolysis stability for its class.
CAS 80693-00-1 · Diphosphite · Secondary antioxidant
Product Overview
PEP-36 (bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite) is a high-melting white powder with a molecular weight of 632.7. It is used with phenolic antioxidants to prevent discoloration and melt-flow change in PP, PE, PS, ABS and PC processing.
Typical specification. Every shipment is supplied with a batch COA; the limits that apply to your order are confirmed in the quotation and contract.
Key Benefits
Melt stability
Keeps melt flow stable through multiple passes.
Hydrolysis stability
Better hydrolysis resistance than many pentaerythritol diphosphites.
Technical Specifications
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 PEP-36 |
| Brand | SUNNOX® PEP-36 |
| CAS No. | 80693-00-1 |
| Chemical Name | Bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite |
| Molecular Formula | C35H54O6P2 |
| Molecular Weight | 632.7 |
| Appearance | White powder |
| Melting Point | ≥235 °C |
Applications by Polymer
Pick an application to see how PEP-36 is normally used and what to confirm before your trial.
Polyolefins
Processing stabilizer with a phenolic antioxidant in PP and PE.
What to confirm for your application
- Resin grade and process (film, fiber, molding, pipe)
- Processing temperature and number of passes
- Current antioxidant package and dosage
Styrenics
Prevents discoloration in PS, HIPS and ABS processing.
What to confirm for your application
- Grade
- Processing temperature
- Color target
Polycarbonate
Used for color stability in PC processing.
What to confirm for your application
- PC grade
- Melt temperature
- Optical requirements
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.
Technical & Buying Information
Antioxidant PEP-36 Buyer Guide
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.
Request a Quotation for Antioxidant PEP-36
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 Antioxidants
SUNNOX® 168
Hydrolysis-resistant phosphite secondary antioxidant for color and melt-flow protection during processing.
View product →SUNNOX® 9228
High-performance diphosphite for high-temperature processing with excellent hydrolysis resistance.
View product →SUNNOX® 1010
High-MW hindered phenolic primary antioxidant for long-term thermal protection with low volatility.
View product →SUNNOX® 1076
Low-melting hindered phenolic primary antioxidant, easy to disperse in film and compounding.
View product →Antioxidant PEP-36 FAQ
PEP-36 or 168?
PEP-36 is more efficient per unit of phosphorus and gives strong processing color; 168 is the general-purpose standard with excellent hydrolysis resistance. The choice depends on your process and storage conditions.
How should it be stored?
Keep bags sealed and dry. Phosphites react slowly with moisture, so avoid humid storage.
Does it need a phenolic antioxidant?
Yes, pair it with a phenolic primary such as 1010 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.
Discuss Your Antioxidant PEP-36 Requirements
Send your application, specification and quantity to request a quotation or supporting documents.