Two reactive handles
The C=C bond copolymerizes and the anhydride ring esterifies, so one raw material serves UPR, alkyd, rosin and copolymer chemistry.
MA
Maleic Anhydride (MA) Supplier from China
Maleic anhydride (MA) is the reactive building block for unsaturated polyester resins, alkyd resins, maleic rosin and styrene–maleic anhydride copolymers, and an intermediate for agrochemicals such as malathion. SUNCHEM supplies MA to resin, coating and synthesis users with a batch COA on every shipment.
CAS 108-31-6 · C₄H₂O₃ · 2,5-Furandione
- Lot COA with every shipment
- Samples for your trials
- Technical support for your trial
Product overview & key benefits
Maleic anhydride combines a reactive double bond with an anhydride group, so it can both copolymerize and esterify. In unsaturated polyester resin (UPR) it supplies the unsaturation that styrene later crosslinks; in alkyds, maleic rosin and coatings it adds acid functionality; with styrene it forms SMA copolymers. It is also the starting point for maleic and fumaric acid, succinic and tetrahydrophthalic anhydride, polymaleic anhydride, and pesticides such as malathion.
For resin makers, purity, color and free maleic acid are the numbers that decide resin color and reactivity.
Sets resin reactivity
The MA share in a UPR recipe controls how much unsaturation styrene can crosslink, and with it the cured hardness and heat resistance.
Specified on your terms
We quote against your purity, color and maleic-acid limits and send the batch COA for each lot.
Technical specifications
| Parameter | Typical value |
|---|---|
| Product name | Maleic Anhydride (MA) |
| Synonyms | 2,5-Furandione; cis-butenedioic anhydride |
| CAS No. | 108-31-6 |
| EC No. | 203-571-6 |
| Molecular formula | C₄H₂O₃ |
| Molecular weight | 98.06 |
| Appearance | White solid (flakes, briquettes or pastilles) |
Purity, color, free maleic acid and ash 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 Industry
Where maleic anhydride is used, and what to confirm before you switch supply.
Unsaturated polyester resins
The largest use. MA is esterified with glycols, often alongside phthalic or isophthalic anhydride, to give the unsaturated backbone that styrene crosslinks in FRP, gelcoats, artificial stone and putties.
Check before trial
- Resin type (ortho, iso, DCPD) and color target
- Purity and free maleic-acid limits
- Delivery form and monthly volume
Alkyd resins, maleic rosin & coatings
Adds acid functionality to alkyd resins, and reacts with rosin to make maleic rosin for printing inks, paper size and coatings.
Check before trial
- Resin or ink type
- Color target
- Bag size that suits your charging
SMA copolymers & polymer additives
Copolymerized with styrene to make SMA resins, polymerized to polymaleic anhydride for water treatment, and grafted onto polyolefins to make compatibilizers.
Check before trial
- Polymer route and initiator system
- Purity required for your polymer grade
- Sample size for a pilot run
Agrochemical & chemical intermediates
An intermediate for malathion and other agrochemicals, and for maleic acid, fumaric acid, succinic anhydride and tetrahydrophthalic anhydride.
Check before trial
- Synthesis route and impurity limits
- Documents your QA team needs
- Annual volume
Selection & comparison
Choosing the right MA grade
| Your requirement | What usually works |
|---|---|
| General-purpose UPR and alkyd resins | Standard industrial-grade MA |
| Light-colored resins and gelcoats | Specify low color and free maleic-acid limits |
| Bagged charging into batch reactors | Solid MA — flakes, briquettes or pastilles |
| Replacing an existing supplier | Send your current TDS or COA; we quote against the parameters you approve |
Packaging & storage
Packaging
Pack size depends on the form (flakes, briquettes or pastilles). Tell us your bag size and pallet requirements with your inquiry.
Storage
Keep bags closed in a cool, dry, ventilated store. Moisture turns MA into maleic acid, and the dust is a skin and respiratory sensitizer — follow the SDS.
Transport
Regulated for transport as a corrosive (UN 2215, Class 8, PG III).
From first email to approved supply
Name the resin or product
UPR, alkyd, rosin, copolymer or an intermediate: tell us which one, because color and maleic-acid limits differ.
Compare the numbers that matter
Purity, color, free maleic acid, ash and iron. Ask for the same parameters on our COA that appear on your incoming-inspection sheet.
Protect the material
MA picks up moisture. Check bag integrity on arrival and keep opened bags sealed, or the maleic-acid content will rise.
Trial, then lock the spec
Run a sample in your own process and keep the approved lot COA as the reference for contract limits.
Tell us your requirement. We match the grade.
Tell us the resin or product you make, the quantity and the destination port. Add your current specification and we will quote against it.
| Information | Example |
|---|---|
| Application | UPR, alkyd, maleic rosin, SMA, intermediate |
| Required specification | Purity, color, free maleic acid |
| Form & packaging | Flakes, briquettes or pastilles; bag size |
| Quantity | Trial order / monthly / annual volume |
| Destination | Country and port |
| Documents needed | COA, SDS, TDS, REACH statement |
Related products
Gamma-Butyrolactone
Solvent and intermediate made from maleic anhydride by hydrogenation.
View product →Maleic Anhydride (MA) FAQ
What is maleic anhydride used for?
Mainly for unsaturated polyester resins. It is also used in alkyd resins, maleic rosin, SMA copolymers, polymaleic anhydride, and as an intermediate for malathion, maleic acid, fumaric acid and succinic anhydride.
Which parameters should I compare between offers?
Purity, color, free maleic acid, ash and iron. For light-colored resins, color and maleic acid usually matter most.
How should maleic anhydride be stored?
In closed bags in a cool, dry, ventilated store. It reacts with moisture to form maleic acid and is a skin and respiratory sensitizer, so follow the SDS for handling.
Is maleic anhydride dangerous goods?
Yes. It is regulated as a corrosive for transport under UN 2215, Class 8, PG III.
