Technical Specifications
| Price Driver | 2024 Direction | Impact on 350cs Cost |
|---|---|---|
| Silicon metal (China) | ↓ Oversupply | Mild deflationary |
| Methyl chloride | Stable | Neutral |
| D4/D5 environmental compliance (EU) | ↑ Tightening | Moderate inflationary |
| Chinese export capacity utilization | ↑ High (>85%) | Competitive CFR pricing |
| EU/US trade barriers on Chinese PDMS | ↑ Increasing | Premium for Western-origin material |
Price Dynamics & Global Trade Flows
PDMS 350cs spot pricing tracks M2 contract prices, correlated with silicon metal, chlorine, and methanol costs. Benchmark CFR Asia: USD 2,200–2,800/MT (2023–2024), compressing in Q4 2024 as Chinese producers operated above 85% capacity. China accounts for over 60% of global PDMS trade volume. EU anti-dumping and US tariff exposure have partially redirected flows toward Korean and German-origin material in premium markets. Long-term contracts achieve 5–8% below spot.
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Frequently Asked Questions
Chemistry & Thermal Stability
PDMS 350cs (CAS 63148-62-9) is a linear polydimethylsiloxane at 350 cSt / 25°C. Si-O backbone delivers −50°C to 200°C continuous service, surface tension ~20.9 mN/m, flash point >300°C, evaporation loss <0.2 wt% at 150°C/3 hr. Chemically inert to most plastics, rubbers, and metals.
Upstream Supply Chain: From Silicon Metal to PDMS
Production begins with silicon metal (Si ≥98.5%) smelted in China's Yunnan, Sichuan, and Xinjiang (65–70% of global output). Muller-Rochow direct process yields dimethyldichlorosilane (M2, ~80%), which is hydrolysed and polymerised through D4/D5 intermediates to target molecular weight. Supply tightness propagates to PDMS spot pricing within 4–8 weeks.
Downstream Demand: Four Core Application Segments
Personal care (25–30%) — skin emollients, hair conditioners, sunscreen spreaders. Industrial mold release (30–35%) — automotive composites, tire manufacturing, rubber molding. Textile processing — softener at 0.3–1.0% on fabric weight. Hydraulic damping — gyroscopes, accelerometers, precision dashpots requiring viscosity-temperature stability.
+Q: What is dimethyl silicone fluid 350cs and what is its CAS number?
A: Linear PDMS, CAS 63148-62-9, 350 cSt at 25°C. Operates −50°C to 200°C, flash point >300°C. Used for mold release, hydraulic damping, textile softening, and cosmetic emollients.
+Q: How does PDMS 350cs differ from 100 cSt or 1000 cSt grades?
A: 350 cSt balances film-forming ability with pumpability. 100 cSt suits spray/volatile-carrier applications; 350 cSt is preferred for mold release and textile baths; 1000+ cSt provides thicker films for heavy-load bearings.
+Q: What are the primary supply chain risks when sourcing PDMS 350cs?
A: Silicon metal availability from China (65–70% of global output). Energy rationing or export controls tighten supply within 4–8 weeks. Maintain 60–90 days safety stock and consider dual-sourcing.
+Q: Is PDMS 350cs approved for cosmetic and personal care formulations?
A: Yes — approved under EU Cosmetics Regulation and FDA 21 CFR for indirect food contact. Non-toxic, non-comedogenic, biocompatible per ISO 10993. Confirm APHA ≤20 and total metals <1 ppm on CoA. INCI: Dimethicone.
+Q: What viscosity-temperature behavior should I expect for precision hydraulic damping?
A: Viscosity index >200 (vs petroleum VI 100–120). From −20°C to 100°C, viscosity varies ~5-fold vs 30–50-fold for mineral oil. No wax crystals or gels at low temperature; no hydrolytic degradation.
+Q: What packaging and export documentation is available for PDMS 350cs?
A: 200 kg steel drums, 1,000 kg IBCs, bulk tank containers. SGS-certified CoA, SDS, UN packaging documentation. Lead time 7–14 days for stock grades; 1 kg samples available. HS code 3910.00.
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