Gelest Silanes, Silicones, Metal-Organics and Acrylates

Selection and quotation of Gelest materials: silane coupling agents and dipodal silanes, SIVATE blends, reactive and inert silicones, ExSil elastomers, metal alkoxides, CVD precursors and Bimax acrylates.

Silane Coupling Agents for Adhesion and Composites

Gelest silanes enhance adhesion, increase mechanical properties of composites and improve dispersion of pigments and minerals. The diamino silane SIA0591.1 (98%) boils at 140 °C at 15 mmHg, and the epoxy silane SIG5839.0 is a coupling agent for latex polymers.

SIA0591.1: purity 98%, 6.5 cSt
SIA0591.1: flash point 150 °C
SIG5839.0: bp 124 °C at 3 mmHg
SIG5839.0: density 1.00 g/mL

Dipodal Silanes and Metal Primers

Dipodal silanes are adhesion promoters with hydrolytic stability up to about 10,000 times greater than conventional silanes. They serve epoxy, urethane, polysulfide and silicone systems. SIB1817.0 is used in corrosion resistant coatings and primers for steel and aluminum.

Hydrolytic stability up to ~10,000x
SIB1817.0: bp 96 °C at 0.3 mmHg
SIB1817.0: purity 97%
SIB1817.0: density 0.957 g/mL

SIVATE Functional Silane Blends

SIVATE blends are silane blends chosen for enhanced reactivity, bonding or surface properties. A610 is an activated amine-functional blend, E610 an enhanced amine blend for corrosion resistance of metal substrates, and A200 an activated acrylate blend. A610 and A200 need no moisture activation.

SIVATE A610: activated amine blend
SIVATE E610: metal substrates
SIVATE A200: activated acrylate blend
A610, A200: no moisture activation

Reactive Silicones for Platinum Addition Cure

Gelest reactive silicones are formulated into coatings, membranes, cured rubbers and adhesives. Vinyl terminated DMS-V31 (1,000 cSt, 28,000 g/mol) is a base polymer for 2-part addition cure elastomers, and the HMS-301 copolymer with 25-35% methylhydrosiloxane serves as the crosslinker.

DMS-V31: 1,000 cSt
DMS-V31: 0.18-0.26 wt.% vinyl
HMS-301: 25-35 cSt
HMS-301: MW 1,900-2,000 g/mol

Inert DMS and FMS Silicone Fluids

Gelest inert silicones serve heat transfer, lubricating, dielectric and optical applications, with viscosities from 0.65 to 2,500,000 cSt. DMS-T21 (100 cSt) has a flash point of 315 °C and pour point of -65 °C; the FMS-123 fluorosilicone flashes at 260 °C and pours at -47 °C.

Range: 0.65 to 2,500,000 cSt
DMS-T21: dielectric constant 2.75
DMS-T21: flash 315 °C, pour -65 °C
FMS-123: density 1.25 g/mL

ExSil and PP2-TC High Elongation Silicones

ExSil 100 is a two-component molding grade elastomer with 4,000-6,000% elongation and 6-7 MPa tensile strength, and ExSil 50 with 6,000% elongation was developed for medical applications. PP2-TC01 is a thermally conductive adhesive for electronic assemblies, PP2-TC02 and PP2-TC03 are gap fillers.

ExSil 100: mix 100:1, 4 h at 80 °C
ExSil 50: durometer 5 Shore A
PP2-TC02: elongation 1,200%
PP2-TC02: specific gravity 2.47

Metal Alkoxides and CVD Precursors

Gelest metal-organics act as catalysts in synthetic reactions, and metal alkoxides such as AKA010 aluminum n-butoxide and AKT885 titanium n-propoxide serve sol gel processes. CVD precursors cover Co, Zr, Ru, Hf and Ta; INCO032 cobalt tricarbonyl nitrosyl is a liquid.

AKA010: aluminum n-butoxide
AKT885: titanium n-propoxide
INCO032: 26 Torr at 0 °C
INCO032: decomposes above 66 °C

Bimax Acrylates and Specialty Monomers

Bimax is the Gelest line of specialty acrylic monomers and polymers formulated into coatings, adhesives, resins and latexes for optical, electronic and industrial applications. The monomers are used in contact lenses, 3D printing photoresins, water treatment flocculants and thickeners.

BIMAX BETA-C (9021): flash 93.5 °C
BIMAX BETA-C: melting point -60 °C
BIMAX BEM 25/100 (9109): mp 50 °C
BIMAX BEM 25/100: flash 110 °C

Choosing a Silane Coupling Agent by Polymer

In the manufacturer selection chart the coupling agent is chosen by functional group for the matrix.

For epoxy, primary screening starts with the amino silane SIA0591.0, the epoxy silane SIG5840.0 and the dipodal SIB1834.0; for urethane with SIA0610.0, SIM6500.0, the isocyanate silane SII6455.0 and the mercapto silane SIM6476.0; for UV cure acrylates with SIA0200.0 and SIM6487.4.

Polycarbonate lists SIA0591.0 and SIA0610.0, polysulfide sealants SIG5840.0, SIB1825.0 and SIM6476.0, and hydroxyl-terminated silicone SIA0605.0, SIA0589.0 and the dipodal SIB1824.0.

Silane Deposition: Concentration, pH and Cure

From aqueous alcohol: a 95% ethanol and 5% water solution is adjusted to pH 4.5-5.5 with acetic acid, silane is added to a 2% final concentration and five minutes are allowed for hydrolysis; the layer cures for 5-10 minutes at 110 °C or 24 hours at room temperature.

For fiberglass the alkoxysilane is dissolved at 0.5-2.0% in water and cured at 110-120 °C for 20-30 minutes. Anhydrous deposition typically takes 4-12 hours at 50-120 °C. Fillers are treated by spraying a 25% silane solution in alcohol.

Formulating a Platinum Addition Cure Silicone

Addition cure forms no byproducts, so parts keep good dimensional stability. Vinyl terminated base polymers typically range from 1,000 to 60,000 cSt, the crosslinker is a copolymer with 15-50 mole % methylhydrosiloxane, and the catalyst is a platinum complex at 5-10 ppm.

By convention part A holds the vinyl silicone and the catalyst, part B the hydride siloxane. Cure below 50 °C runs at room temperature, from 50 to 130 °C at low temperature and above 130 °C at high temperature. Hexamethyldisilazane-treated fumed silica is used for reinforcement.

Choosing a Silicone Fluid by Viscosity and Temperature

DMS-T21 at 100 cSt has a viscosity temperature coefficient of 0.6, a pour point of -65 °C, a flash point of 315 °C, surface tension of 20.9 mN/m and a dielectric constant of 2.75.

The FMS-123 fluorosilicone at 300-350 cSt has a coefficient of 0.84, a pour point of -47 °C, a Tg of -74 °C and a dielectric constant of 6.95.

Inert silicone viscosities in the range run from 0.65 to 2,500,000 cSt, so a fluid is selected by working temperature range and required viscosity per the TDS.

Gelest and model names are trademarks of their respective owners and are used only to identify the equipment for which we source parts. SpareX is not an official dealer, distributor or representative of Gelest and is not affiliated with the trademark owner. Origin, documents and warranty are stated for each item in the quotation.