Buying TMAU: What Matters
Tetramethylol acetylenediurea (TMAU, CAS 5395-50-6) is a formaldehyde-based crosslinker supplied as a solid or an aqueous solution. Buying it well means confirming the identity (and the correct chemistry behind the misleading name), checking the assay and the all-important free-formaldehyde figure, and matching the form and grade to your process.
For the chemistry behind these points, see our main article on TMAU (CAS 5395-50-6).
Step 1: Confirm the Identity and Chemistry
| Item | What to confirm |
|---|---|
| Common name | Tetramethylol acetylenediurea (TMAU) |
| Correct chemical name | 1,3,4,6-Tetrakis(hydroxymethyl)glycoluril |
| CAS number | 5395-50-6 |
| Formula / MW | C8H14N4O6 / 262.22 g/mol |
Be alert to descriptions that say TMAU contains a carbon-carbon triple bond: it does not. TMAU is a glycoluril-based methylol crosslinker.
Step 2: Read the Specification
| Parameter | Why it matters | Typical value |
|---|---|---|
| Assay / active content | The useful content | Often 98% or higher |
| Appearance | Confirms a clean solid or clear solution | White to off-white solid |
| Melting point | Identity and purity | Approx. 137-138 deg C |
| Free formaldehyde | Key regulatory and performance parameter | Per customer/regulatory limit |
| Moisture | Stability and dosing | Low, kept dry |
Free formaldehyde is the parameter that most distinguishes grades, especially for textile and consumer-facing applications where released-formaldehyde limits apply.
Step 3: Match the Form and Grade
- Solid. The crystalline crosslinker, dissolved on site.
- Aqueous solution. Easier dosing into textile baths and coating systems.
- Formulated systems. Blend-compatible with catalysts, softeners and other finishing agents.
- Low-free-formaldehyde grades. For tighter formaldehyde requirements.
Step 4: Secure the Documentation
- SDS covering formaldehyde-related hazards and controls.
- Per-batch COA reporting assay, melting point and free formaldehyde.
- Regulatory statements confirming the status (for example REACH/TSCA) and applicable formaldehyde limits for your market.
Supplier Checklist
- Identity. CAS 5395-50-6 and the correct glycoluril chemistry confirmed.
- Assay and free formaldehyde. Within specification and your limits.
- Form. Solid or solution, suited to your process.
- Catalyst compatibility. Grade suits your cure system.
- Documentation. SDS, per-batch COA and regulatory statements.
- Consistency. Batch history if free formaldehyde or colour is critical.
Common Buying Mistakes
- Being misled by the name. “Acetylenediurea” does not mean an alkyne; confirm the glycoluril chemistry.
- Ignoring free formaldehyde. It determines market access for many textile and consumer uses.
- Mismatching the form. Solid versus solution affects dosing and process.
- Skipping documentation. A formaldehyde-based crosslinker needs full SDS/COA and regulatory confirmation.
- Poor storage. Heat, acid or base can cause decomposition and formaldehyde release.
How PolyBlueChem Can Help
PolyBlueChem can supply TMAU (CAS 5395-50-6), with the documentation appropriate to your application. To request current specifications, a COA or a quotation, contact the PolyBlueChem team.
Frequently Asked Questions
What should I look for when buying TMAU?
Confirm the CAS (5395-50-6) and the glycoluril chemistry, check the assay and free-formaldehyde figure, choose the right form and grade, and secure the SDS, COA and regulatory statements.
What is the most important specification parameter?
For many applications, free formaldehyde, because it determines regulatory compliance and market access; assay and melting point complete the picture.
Is TMAU the same as DMDHEU?
No. Both are methylol crosslinkers, but TMAU is glycoluril-based and DMDHEU is a dihydroxyethyleneurea, with different performance and formaldehyde profiles.
What documents should come with a shipment?
At minimum an SDS and a per-batch COA, plus regulatory statements covering formaldehyde limits for your market.
How should TMAU be stored?
Sealed, cool and dry, away from strong acids, bases and heat.