SYNTECH

1. Creates stable permanent dyeing sites for cationic dyes

SAS’s covalently bonded −SO3​Na strong acid sulfonate groups stay fully ionized in acidic dye baths (pH 2–7), unlike carboxyl monomers that lose negative charges under acid. They form firm ionic bonds with positively charged cation dyes, greatly boosting color depth, saturation and dark color dyeing performance. Fibers achieve uniform, rich shades without extra dye consumption.

2. Delivers consistent level dyeing & eliminates color defects

Hydrophilic sulfonate groups loosen the tight crystalline structure of PAN polymer chains, raising internal fiber free volume. Dye liquor penetrates fiber rapidly and evenly, avoiding surface floating color, barreling and uneven shade common in unmodified acrylic fiber. Stable dyeing effect is maintained even with industrial hard water containing Ca²⁺/Mg²⁺.

3. Improves textile processing performance

1. Permanent antistatic property: Continuous anionic sulfonate channels reduce static buildup during spinning, weaving and daily wear, less fabric sticking and dust adsorption.
2. Optimized fiber flexibility: Reduces brittleness of pure polyacrylonitrile, delivering soft wool-like hand feel and better crimp retention, ideal for blankets, sweaters and plush fabrics.
3. Lower filament breakage rate in wet spinning: Stabilizes polymerization system, smooths spinning production and lifts yield.

4. Excellent thermal stability to avoid yellowing

SAS modified PAN fibers resist thermal degradation during high-temperature spinning, heat setting and post-dye treatment. It effectively suppresses fiber yellowing, keeping bright, clean fabric color long-term.

5. Balanced polymerization characteristics for mass production

• Mild copolymerization activity, easy to match AN and acrylate second monomers in conventional aqueous suspension polymerization for acrylic fiber.
• Cost-effective with large-scale domestic bulk supply, far lower material cost than SMAS for standard staple fiber production.
• No residual free small-molecule emulsifiers after film/fiber forming; no surface blushing or water resistance decline after repeated washing.

6. Superior color fastness

Ionic binding between sulfonate groups and cation dyes is stable against washing, rubbing and light exposure. Finished acrylic textiles feature outstanding color fastness and rarely fade after repeated laundering.

7. Wide formula adaptability

Suitable for light, medium and dark color acrylic staple fiber, bulky yarn and carpet fiber. Standard dosage 0.8–1.5 mol% covers most mainstream textile production lines, easy formula tuning without major equipment adjustments.