Potassium Persulfate (KPS)
CAS Number: 7727-21-1
Potassium Persulfate (K2S2O8) is a high-purity, water-soluble peroxide salt primarily used as a thermal initiator in emulsion and suspension polymerization of acrylic, styrene, vinyl acetate, butadiene and acrylonitrile monomers. Its decomposition into sulfate radicals at 50-80 C provides controlled, reproducible initiation rates and yields polymers with low residual monomer and narrow molecular weight distribution. KPS is also used for desizing in textile finishing, as a depolymerization agent for starch and cellulose, and as a strong oxidant in analytical chemistry. Compared with ammonium persulfate, KPS is preferred where ammonium ions interfere with the final application (e.g., latex for paper coating).
Technical Specifications
| Cl (ppm) | ≤30 |
| Fe (ppm) | ≤5 |
| packaging | 25 kg PE-lined kraft bag; 500/1000 kg jumbo bag |
| appearance | White crystalline powder |
| moisture (%) | ≤0.1 |
| active oxygen (%) | ≥5.85 |
| purity K2S2O8 (%) | ≥99.0 |
| pH (1% solution, 25°C) | 3.0-4.5 |
| UN number / hazard class | UN 1492 / Class 5.1 oxidizer |
| solubility in water (20°C, g/100g) | 5.2 |
Applications
- Thermal initiator for emulsion polymerization of acrylic, styrene-acrylic, SBR and PVAc latexes
- Suspension polymerization initiator for PVC, PMMA and copolymer beads
- Redox initiator system component (paired with bisulfite or metabisulfite)
- Textile desizing and bleaching booster in cotton processing
- Starch oxidation and modification for paper sizing and adhesives
- Analytical reagent for COD digestion and total nitrogen determination
Key Features
- Clean thermal decomposition profile for reproducible initiation rates in emulsion polymerization
- Ammonium-free, preferred where NH4+ would interfere (paper coating, food-contact latex)
- Compatible with redox initiator systems for low-temperature initiation
- Lower water solubility than NaPS/APS - suited to slow-release dosing in suspension processes
- Narrow molecular weight distribution and low residual monomer in resulting polymers
- UN 1492 Class 5.1 oxidizer, ocean-shipment ready
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CAS Number
7727-21-1
Category
Polymer Synthesis ChemicalsAvailability
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