In organosilicone-polyurethane (Si-PU) copolymer modification, the "purity of end-group reactivity" and "hydroxy type" directly dictate chain insertion efficiency with isocyanate, moisture permeability vs hydrophobic balance, and long-term hydrolysis resistance. Conventional polyether-modified silicones (PEG/PPG capped) leave unreacted polyether, causing bubbles/yellowing/poor water resistance with NCO; silanol-methyl silicones (Si–CH₂OH) react but weaker thermostability/PU compatibility. As synthetic leather, elastomers, medical films, and high-soft coatings demand "di-carbon-hydroxy, zero polyether residue, Mn3000, copolymerizable non-blocking," sourcing a carbon-hydroxy modified silicone with functionality 2, visc 70cSt, nD 1.41, high purity has become the core gap for domestic Si-PU copolymer intermediate localization.
Addressing this "carbon-hydroxy copolymer" pain point,
Anhui IOTA Silicone Oil Co., Ltd. (IOTA) officially launches
Carbon-Hydroxy Modified Silicone Oil IOTA 28830 (chemical name: carbon-hydroxy modified PDMS). Characterized by "colorless to light yellow transparent/slightly hazy liquid, functionality 2, Mn 3000, visc 70cSt (25℃), nD 1.41, 20L/200L iron drums, 24-month shelf," and backed by "di-carbon-hydroxy pure functionality + zero polyether residue + PDMS mainchain permeable-hydrophobic," it serves as the "silicone-soft anchor" for PU resin modification, synthetic leather topcoat softening, elastomer fold-enhancement, and moisture-permeable membrane copolymerization.
Molecular Architecture: Di-Carbon-Hydroxy + PDMS Backbone Ether-Free Logic
The core competitiveness of IOTA 28830 stems from its "PDMS backbone – both ends –CH₂CH₂OH-type carbon hydroxy" clean structure:
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Di-Carbon-Hydroxy Pure Functionality: Both ends capped with alcoholic hydroxyl (–CH₂–CH₂–OH or equivalent carbon-chain OH), functionality strictly 2, chains with diisocyanate (MDI/TDI/HDI) at n(OH):n(NCO)=1:1~1.05 for precise extension—no mono/tri-end impurities, no gel particles; unlike polyether silicones, no –O–CH₂CH₂– ether repeats, eliminating unreacted PEG tack and yellowing.
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Mn3000 Soft-Segment Fit: Mn3000 ≈ 40 siloxane units—as soft segment in PU, gives PDMS low-Tg (< -50℃) flexibility, yet length moderate enough to avoid excessive phase separation; film soft without creep, MIT fold >100k no crack.
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PDMS Backbone Perm-Hydrophobic: Siloxane inherits low surface energy (water CA >100°), but chain interstices allow water "dissolve-diffuse" (MVTR 30-50% higher vs pure PU)—"outer hydrophobic inner permeable" self-clean & comfort; nD 1.41 near PU (1.45-1.50), blend non-hazy.
Performance Leap: From "Polyether Residual Tack" to "Carbon-Hydroxy Pure Copoly"
Incorporating IOTA 28830 enables qualitative leaps in resin modification:
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PU Soft-Fold Jump: In wet/dry PU synthetic leather 5-15% into prepolymer—leather supple rebound, room-temp fold >200k no crack, -20℃ no brittle, hand near genuine leather.
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Permeable Self-Clean Film: Co-extrude or coat with TPU—MVTR 8000-12000 g/m²·24h, water CA >110°, oil wipe-off, fits sportswear/medical breathable dressings.
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Elastomer Wear-Quiet: In CPU rollers/screens, cuts friction 15-20%, lifts abrasion, silicone segment suppresses static dust.
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Coating Hand Mod: Wood lacquer, leather finish 2-5%—film slip, anti-fingerprint, dry-rub >5000 cycles.
Application Penetration: From Synthetic Leather Topcoat to Medical MVTR Film
IOTA 28830 covers sectors quadruply sensitive to "soft + fold + permeable + copolymerizable":
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Synthetic Leather: Shoe upper, furniture leather, automotive interior PU topcoat mod.
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Elastomers: Cast PU rollers, seals, screens, gear lube mod.
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Films & Coatings: MVTR waterproof membrane, medical dressing, outdoor apparel coat, self-clean glass coat.
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Specialty Resins: Silicone-modified PU adhesive, high-resilience foam stabilizer.
IOTA Technical Guide: Water-Off, No Base, NCO Match
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Copoly Charge: Dehydrate IOTA 28830 with polyol (e.g., PTMG) at 100-110℃ vacuum 2h (water <0.05%), cool to 60℃ add diisocyanate prepolymer, NCO/OH mol 1.02-1.05; silicone oil suggested 10-30% of total prepolymer OH value.
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Post-Blend Mod: If only sensory mod (no chem bond), cold-blend 5-10% into PU solution (DMF/THF) high-shear; but wash-durability weaker than copoly.
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Taboo Red Line: Strictly no long contact with acid/base/amine/tin cat (hydroxy esters with acid, dehydro with base, competes NCO with amine); sealed moisture-proof (end-OH absorbs water consuming NCO→bubbles); away from open flame (silicone alcohol combustible though flash not listed).
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Storage: 20L/200L iron drums, reactive silicone intermediate non-haz; cool dry sealed, 24 months shelf; shake before use, slight surface oxid-yellowing filterable if hydroxy value intact.
Industry experts note that under the dual cycle of "DMF-free high-physics synthetic leather" and medical MVTR film localization, polyether-residue-free carbon-hydroxy silicone is becoming the "clean soft segment" for Si-PU copolymer. IOTA 28830, with its "Mn3000 di-carbon-hydroxy + 70cSt + ether-free pure function" hard metrics,
fills the domestic supply chain gap for carbon-hydroxy modified silicone oil in PU copolymer soft-fold fields, providing a mass-producible path to replace imported Momentive Silwet series, Shin-Etsu modified silanols for downstream resin plants. This confirms domestic modified silicones are advancing steadily along "end-group carbon-hydroxylation → zero polyether residue → Mn designable," with continuously strengthening technical purity in Si-PU copolymer intermediates.
