Products›Silicone Materials›Defoamers Hub›MeFoam-PE Low-MW
MeFoam-PE Low-MW (Polyether-Modified Silicone Defoamer, Low Molecular Weight): Fast-Acting Defoamer for Water-Based Coatings and Inks
SEMITECH MeFoam-PE Low-MW is the fast-acting polyether-modified silicone defoamer for water-based coatings, printing inks, and air-entrained construction systems where quick foam knockdown matters more than long-term persistence. 25 kg HDPE pail, 2–4 week ex-China lead time.
Contents
| Polyether-PDMS | 0.05–0.3% | 25 kg |
|---|---|---|
| Chemistry | Typical loading | MOQ (HDPE pail) |
Chemistry & Specifications
Polyether-grafted PDMS, 30–50 cP viscosity, hydrophobic silica nucleator, glycol carrier; spreads fast on aqueous foam.
Low-MW PDMS backbone (Mw 5,000–15,000) with polyether side chains at 5–15 mol%. Viscosity 30–50 cP (substantially lower than High-MW at 200–500 cP). Active content 100% in glycol carrier with 1–3% hydrophobic silica nucleator. The polyether modification provides emulsion stability in waterborne formulations while the silicone backbone delivers the surface-tension differential (~20 mN/m vs 35–60 mN/m for foam) that drives spreading.
Defoaming Mechanism: Fast Spreading + Bubble Film Rupture
Spreads on bubble film, displaces surfactant via lower surface tension, hydrophobic silica nucleates rupture.
Foam knockdown in 5–15 seconds in standard 0.5% SDS test. The trade-off is persistence: Low-MW re-disperses into bulk over time, requiring re-dosing after 2+ hours.
- Loading 0.05–0.15% — water-based coatings; clear-coat and pigmented architectural emulsions
- Loading 0.10–0.20% — flexographic and roto-gravure printing inks
- Loading 0.15–0.30% — air-entrained construction (concrete admixture, cement grout)
- Loading 0.05–0.15% — adhesive emulsions (PVAc, EVA copolymer)
Pairing strategy: dose 0.10% Low-MW at let-down for fast defoaming, then 0.05% High-MW after 30 min for sustained persistence during shipping and end-use.
▶Show full content (5 sections)
Applications & Formulation Guidance
Water-based coatings (largest), printing inks, construction admixtures, polymer emulsions, water-treatment.
Waterborne coatings (largest) — emulsion paints, waterborne wood coatings at 0.05–0.15%. Printing inks — flexo and gravure at 0.10–0.20%; fast kinetics critical since foam-bubble defects are immediate rejects. Concrete admixtures — 0.15–0.30% for air content control. Polymer emulsion manufacture — 0.05–0.15% during polymerisation. Avoid for sustained anti-foam in long-storage applications — specify High-MW or MeFoam-S.
Procurement, Storage and Quality Control
CoA per shipment; 25 kg HDPE pail; 12-month sealed shelf life; tolerates ambient handling; non-flammable.
CoA per batch: viscosity (30–50 cP), silicone content (≥98%), silica (1–3%), water (≤0.5%). MOQ 25 kg. Lead time 1–2 weeks Asia, 4–6 weeks Europe/North America. Non-flammable; avoid freezing (breaks silica-PDMS dispersion irreversibly). Compatibility testing mandatory before production-scale dosing. REACH-registered; FDA 21 CFR 175.300 for indirect food-contact.
MeFoam-PE Low-MW Specification Sheet
SEMITECH stocked grade; CoA per batch.
| Property | Specification | Test Method |
|---|---|---|
| Chemistry | Polyether-modified PDMS + hydrophobic silica | — |
| Form | 100% active in glycol carrier | — |
| PDMS Mw (typical) | 5,000–15,000 g/mol | GPC |
| Active silicone content | ≥98% | Solvent extraction |
| Hydrophobic silica content | 1–3% | Ash analysis |
| Appearance | Cloudy white to off-white liquid | Visual |
| Density (25°C) | 0.97–1.00 g/cm³ | ASTM D1475 |
| Viscosity (25°C) | 30–50 cP | Brookfield |
| Surface tension (1% aq.) | 22 ± 2 mN/m | Du Noüy ring |
| pH (1% aq.) | 6.0–8.0 | pH meter |
| Water content | ≤0.5% | Karl Fischer |
| Flammability | Non-flammable (flash point >150°C) | ASTM D93 |
| Solubility | Self-emulsifies in water; soluble in glycols, esters | — |
| Packaging | 25 kg / 200 kg HDPE pail or drum | — |
| Shelf life | 12 months sealed below 30°C | — |
FAQ
+When should I choose Low-MW over High-MW?
Choose Low-MW when kinetics matter more than persistence: production-line foam knockdown (5–15 sec), printing inks (consumed within minutes), construction admixtures. Choose High-MW for shelf-stable retail paint and long-running process water systems. Common pairing: 0.10% Low-MW + 0.05% High-MW.
+Will MeFoam-PE Low-MW cause fish-eyes on my waterborne paint?
Properly compatibility-tested, no. The polyether modification reduces incompatibility versus non-modified PDMS. Surface defects occur when loading exceeds 0.3% or the substrate has very low surface energy. Run a draw-down test on actual substrate before scaling.
+Low-MW vs alkyl-silicone defoamers in waterborne paints?
Polyether-modified outperforms pure alkyl-silicone 2–3x on surface-defect frequency. Alkyl-silicone is ~40% cheaper but phase-separates in 4–8 weeks. Use polyether for retail paint; alkyl-silicone for industrial coatings consumed within 1–2 weeks.