Many R&D engineers often confuse Sodium Methallyl Sulfonate (SMAS) and Sodium Allyl Sulfonate (SAS). Although both belong to sulfonate functional monomers, subtle structural differences lead to completely different application limits.
SMAS (CAS 1561-92-8): Contains methyl branch on carbon chain, stronger steric hindrance.
SAS (CAS 2495-39-8): Linear molecular structure, no methyl side group.
Core Performance Difference
✅ Slump retention: SMAS > SAS, preferred for high-performance polycarboxylate superplasticizer
✅ High temperature & salt resistance: SMAS shows better stability in harsh water environment
✅ Polymer steric effect: SMAS-modified polymer has stronger anti-flocculation capacity
✅ Cost: SAS is cheaper, fit for low-end common dispersant; SMAS for high-end demanding formulas
Recommended Selection Principle
👉 Choose SMAS: PCE superplasticizer, acrylic fiber, high-temperature oilfield polymers, high-salinity water treatment agents
👉 Choose SAS: Ordinary low-demand dispersants, general emulsion additives without strict long-term stability requirements
Sentai supply both SMAS and SAS with stable quality. If you cannot confirm which monomer fits your formula, send your application conditions to our technical team, we provide professional selection suggestions and sample support.
