Reactive, built into the polymer
The P–H group reacts into epoxy and polyester, so it does not migrate.
DOPO
DOPO Flame Retardant Supplier from China
DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide) is a reactive phosphorus flame retardant and intermediate used mainly in halogen-free epoxy resins for printed circuit board laminates, and in polyester fibers and other polymers. SUNCHEM supplies DOPO with a batch COA on every shipment; the TDS is sent on request.
CAS 35948-25-5 · C₁₂H₉O₂P · 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-oxide
- Lot COA with every shipment
- Samples for your trials
- Technical support for your trial
Product overview & key benefits
DOPO carries a reactive P–H bond that adds to epoxy groups, double bonds and carbonyls, so it can be built into the polymer chain rather than blended in. Its largest use is in halogen-free epoxy resins for copper-clad laminates and printed circuit boards; it is also used to make flame-retardant polyester fibers and as an intermediate for DOPO derivatives and other phosphorus flame retardants.
Purity, melting point and moisture matter because the P–H group is sensitive to oxidation and hydrolysis.
Halogen-free laminates
The basis of many halogen-free epoxy systems for PCBs.
Specified on your terms
We quote against your purity, melting point, moisture and chloride and send the batch COA for each lot.
Technical specifications
| Parameter | Typical value |
|---|---|
| Product name | DOPO |
| Synonyms | 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-oxide |
| CAS No. | 35948-25-5 |
| EC No. | 252-813-2 |
| Molecular formula | C₁₂H₉O₂P |
| Molecular weight | 216.17 |
| Appearance | White powder or flakes |
Purity, melting point, moisture and chloride limits depend on the producer grade and are stated on the TDS and batch COA; the limits for your order are confirmed in the quotation and contract.
Applications by Polymer
Where DOPO is used, and what to confirm before you switch supply.
Halogen-free epoxy for PCB laminates
Reacted with epoxy or phenolic novolac to make phosphorus-containing resins for copper-clad laminates.
Check before trial
- Resin route
- Purity and chloride
- Monthly volume
Flame-retardant polyester fibers
Used to make phosphorus-containing comonomers for flame-retardant PET fibers.
Check before trial
- Polymer route
- Purity
- Bag size
DOPO derivatives
An intermediate for DOPO-HQ and other phosphorus flame retardants.
Check before trial
- Synthesis step
- Impurity limits
- Sample for trials
Selection & comparison
Choosing the right DOPO grade
| Your requirement | What usually works |
|---|---|
| PCB laminate epoxy | High-purity DOPO with low chloride |
| Polyester fiber comonomers | Specify purity and melting point |
| Intermediate for derivatives | Standard grade |
| Replacing an existing supplier | Send your current TDS or COA; we quote against the parameters you approve |
Packaging & storage
Packaging
Tell us the bag or drum size and pallet requirements you need; we confirm the packaging with the quotation.
Storage
Keep bags sealed in a cool, dry store; DOPO is sensitive to moisture and oxidation.
From first email to approved supply
Name the end use
Name the polymer and the fire rating you must meet — UL 94 class and thickness, LOI or cable standard.
Compare the numbers that matter
Purity, melting point, moisture and chloride.
Protect the material
Keep bags sealed and dry; moisture and air degrade the P–H group.
Trial, then lock the spec
Compound a trial batch, run your fire and mechanical tests, and keep the approved lot COA as the reference.
Tell us your requirement. We match the grade.
Tell us the polymer, the fire rating you need, the quantity and the destination port. Add your current specification and we will quote against it.
| Information | Example |
|---|---|
| Application | PCB epoxy, polyester fiber, derivatives |
| Required specification | Purity, melting point, chloride |
| Packaging | Bag or drum size; pallets |
| Quantity | Sample / trial order / annual volume |
| Destination | Country and port |
| Documents needed | COA, SDS, TDS, RoHS/REACH |
Related products
DOPO FAQ
What is DOPO used for?
Mainly to make halogen-free phosphorus-containing epoxy resins for PCB laminates; also for flame-retardant polyester fibers and as an intermediate for other phosphorus flame retardants.
Is DOPO additive or reactive?
Reactive: its P–H group bonds into the polymer.
Which parameters should I compare between offers?
Purity, melting point, moisture and chloride.
Can I get the TDS?
Yes. Send an inquiry with your application and we email the TDS.
