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Hydrophilic silicones differ from conventional silicones by demonstrating a much greater compatibility with aqueous systems. They have slight to complete solubility in water. They are composed of dimethylsiloxane molecular backbones in which some of the methyl groups are replaced by polyalkylenoxy or pyrrolidone groups linked through a propyl group to the silicon atom.

They are widely used as surfactants and emulsifiers. By altering the amounts of hydrophile and lipophile, the desired surfactant properties may be balanced. The higher the alkylene oxide content, the higher the hydrophilicity. Materials with ethylene oxide contents of 75% and higher are freely soluble in water.

DBE-712 is the lowest molecular weight material containing 6-8 EO units and is miscible with water in all concentrations. It is used as an anti-fog treatment for glass and optical surfaces. It is also used to facilitate wetting and spread of developers on lithographic plates. At the other extreme, DBE-224 is a water-insoluble copolymer used as a lubricant in plastic on metal wear applications and as a lubricant for fibers. Anti-tack and mar resistance are imparted to urethane coatings. High molecular weight copolymers, such as DBE-224, are excellent emulsifiers. DBE-821  reduces static charge generation during fiber processing. It has also been incorporated into rolling oil formulations for metal drawing and stamping. DBE-712 and DBP-732 provide slip in flexographic and gravure inks. CMS-832 is a high refractive index fluid that provides gloss and smooth touch in polishes.

Polyalkylene Oxide Silicones

Hydrophilic Silicones (R=OMe): Dimethylsiloxane-Ethylene Oxide Block/Graft Copolymers

Product codeWt% non-siloxaneGlycol cappingViscosity (cSt)Molecular weightDensityRefractive indexPour point (°C)Water solubilitySurface tensionCASComments
DBE-22425OMe40010,0001.021.414-29-23.868938-54-5~10 mole% EO-substituted
DP ~100
DBE-31130-35OMe10800-1,2000.971.425-----68938-54-5R&D only
DBE-41145-50OMe5-10400-5000.941.425-----68938-54-5R&D only
DBE-62150-55OMe1002,5001.031.434-15+/-23.168938-54-5~25% EO-substituted;
DP ~15
DBE-71260-70OMe206001.011.4420+23.627306-78-1reduced volatility grades available
DBE-73265-70OMe180020,0001.021.446-50+2267762-85-0EO/PO (40/60)
DBE-71375OAc30600-7501.031.446--+--125997-17-3--
DBE-81480OMe40-501,0001.041.452-14+26117272-76-1reduced volatility grades available
DBE-82180-85OMe100-1204,4001.071.4540+2768938-54-5reduced volatility grades available
DBE-92185-90OMe100-1205,0001.081.4510+37.368938-54-5-

Hydroxylic Silicones (R=OH)

Product codeWt% non-siloxaneGlycolGlycol cappingViscosity (cSt)Molecular weightDensityRefractive indexCAS
CMS-22120-25EOOH125-1504,0001.001.419[68937-54-2]
CMS-22220POOH150-2005,500-6,5000.981.411[68957-00-6]
DBP-C2245-55POOH400-3002,500-3,2000.991.434[161755-53-9]
DBE-53455EO/PO (60/40)OH4,00030,0000.981.414[68937-55-3]
CMS-832*50-60EOOH1,000-2,0002,000-5,0001.091.505[200443-93-2]
DBE-C2560EOOH400-4503,500-4,5001.071.450[68937-54-2]
CMS-62665EOOH550-6504,500-5,5001.091.458[68937-54-2]
*(Hydroxypolyethyleneoxypropyl)methylsiloxane-(3,4-Dimethoxyphenylpropyl)methylsiloxane-Dimethylsiloxane terpolymer

Polar silicones are utilized in specialty applications where readily swellable materials such as soft rubber have poor dimensional stability in contact with other lubricants. Pyrrolidone-functional silicones are the most hydrophilic silicones that are not derived from polyethylene glycols (PEGs). Furan-functional silicones are hydrophilic and have compatibility with most conventional silicones. Cyanoalkylsilicones have even less tendency to swell substrates than fluorosilicones and, in thin films, facilitate ion transport. Fluorosilicones are the most common polar silicones, but are usually considered as a class by themselves.

(N-Pyrrolidonepropyl)methylsiloxane-dimethylsiloxane copolymer, carboxylate substitution

(N-Pyrrolidonepropyl)methylsiloxane-dimethylsiloxane copolymer, dimethylaminopropylcarboxamide substitution

(N-Pyrrolidonepropyl)methylsiloxane-Dimethylsiloxane Copolymers

Product codePyrrolidone SubstitutionViscosity (cSt)DensityWater solubilityRefractive indexCAS
YAD-122dimethylaminopropylcarboxamide150-3000.96--1.406[179005-02-8]
YBD-125carboxylate400-6000.98--1.405[179005-03-9]

Tetrahydrofurfuryloxypropylmethylsiloxane

Tetrahydrofurfuryloxypropylmethylsiloxane

Product codeMole % Tetrahydrofurfuryloxypropyl-methylsiloxaneViscosity (cSt)DensityWater solubilityRefractive indexCAS
DCF-40510050.93--1.426[1361237-41-3]

Cyanopropylmethylsiloxane

Cyanopropylmethylsiloxane

Product CodeMole % CyanopropylmethylsiloxaneViscosity (cSt)DensityWater solubilityRefractive indexCAS
YMS-T31100800-1,4001.07--1.459[67762-86-1]

Silicone fluids which are both hydrophilic and olephilic are said to be amphiphilic. This is in distinction to the more general definition that considers an amphiphile to be a material which is both hydrophilic and hydrophobic. Amphiphilic silicones have the ability to form stable water-in-oil emulsions allowing formulation of a wide range of gels and creams. They are also useful as surface treatments for dispersion of polar particles in hydrocarbon media.

Dodecylmethylsiloxane-Hydroxypolyalkyleneoxypropylmethylsiloxane Copolymer, CAS: [145686-74-4]

Product CodeViscosity (cSt)Molecular weightMole % hydroxypolyalkyleneoxy-propylmethylsiloxaneActive %Density
ABP-2631,000-4,0001,800-2,00030-4080-850.85
contains 15-20% isostearyl alcohol