Silicon-based Monomers for Adhesives and Sealants

HMS -064 by Gelest (Mitsubishi Chemical) is 5-7% (Methylhydrosiloxane) and 93-5% (dimethyl-siloxane copolymer). This trimethylsiloxy terminated hydride functional polymer undergoes three main classes of reactivity: hydrosilylation, dehydrogenative coupling and hydride transfer. HMS -064 has more readily controlled reactivity than the homopolymers which results in tougher polymers with lower cross-link density. The preferred catalysts for the reactions are platinum complexes such as SIP6830.3 and SIP6832.2. In principle, the reaction of hydride functional siloxanes with vinyl functional siloxanes takes place at 1:1 stoichiometry. HMS -064 is used in encapsulant applications.

Dynasylan® SILBOND® EG by Evonik is tetraethyl orthosilicate. It has 99.8% of the active content and contains low water content. It is an excellent source of high purity silica. It gets hydrolyzed in water. Dynasylan® SILBOND® EG is an excellent source of high-purity silica for sol-gel processes

HMS -301 by Gelest (Mitsubishi Chemical) is 25-35% (methylhydrosiloxane) 65-70% (dimethylsiloxane) copolymer. This trimethylsiloxy terminated hydride functional polymer undergoes three main classes of reactivity: hydrosilylation, dehydrogenative coupling and hydride transfer.

• It has more readily controlled reactivity than the homopolymers which results in tougher polymers with lower cross-link density.
• The preferred catalysts for the reactions are platinum complexes such as SIP6830.3 and SIP6832.2.
• In principle, the reaction of hydride functional siloxanes with vinyl functional siloxanes takes place at 1:1 stoichiometry.
• HMS -301 is used in encapsulant applications.

Dynasylan® SILBOND® 40 by Evonik is an ethyl polysilicate liquid with low viscosity. It is a concentrated form of available silica. It is a partially hydrolyzed mixture of monomers, dimers, trimers and higher polymers. Average -Si-O-Si- chain length is approximately five. Dynasylan® SILBOND® 40 is used in the manufacture of less concentrated or more highly hydrolyzed binders. It has a minimum shelf life of 12 months.

Dynasylan® SILBOND® 50 by Evonik is ethyl polysilicate. It is one of the most concentrated forms of available silica. It is a partially hydrolyzed mixture of monomers, dimers, trimers, and higher polymers. It is hydrolyzed in water and miscible with organic solvents. Dynasylan® SILBOND® 50 is used in the manufacture of less concentrated, more highly hydrolyzed binders.

Silquest™ A-137 Silane by Momentive Performance Materials is a monomeric alkyl alkoxysilane. It reduces efflorescence and staining of surface. It provides excellent protection for bricks, stone, masonry, wood and other substrates. Silquest™ A-137 Silane enhances the performance, dispersibility and compatibility of filler and pigment particles in sealants. The particulate surface is made more hydrophobic and organic-like and becomes more compatible with adhesive and sealant vehicles.

DMS -H41 by Gelest (Mitsubishi Chemical) is hydride terminated polydimethylsiloxane. This polymer undergoes three main classes of reactivity: hydrosilylation, dehydrogenative coupling and hydride transfer. The silanol terminated polydimethylsiloxanes react with hydride functional siloxanes to produce foamed silicone materials. In addition to the formal chemistry described above, the presence of oxygen and moisture also influences cross-link density and foam structure. It is chain extender for vinyl-addition silicones, enabling low viscosity, high elongation formulations. DMS -H41 is used in encapsulant applications.

DMS -V35R by Gelest (Mitsubishi Chemical) is vinyl terminated polydimethylsiloxane. This polymer is employed in addition cure (platinum cure) which provides an extremely flexible basis for formulating silicone elastomers. The vinylmethylsiloxane copolymers are mostly employed in peroxide activated cure systems which involve peroxide induced free radical coupling between vinyl and methyl groups. The formulation of addition cure silicones must address the strength, hardness, consistency, temperature of cure, work time (speed of cure), shelf life and compounding. This reduced volatility grade does not form any by product which allows fabrication of parts with good dimensional stability. Its relatively low viscosity is employed as grafting additives to EPDM elastomers in the wire and cable industry to improve electrical properties. DMS -V35R is also used in sealants and encapsulants applications.

DMS -H31 by Gelest (Mitsubishi Chemical) is Poly (dimethylsiloxane) hydride terminated. This polymer undergoes three main classes of reactivity: hydrosilylation, dehydrogenative coupling and hydride transfer. The silanol terminated polydimethylsiloxanes react with hydride functional siloxanes to produce foamed silicone materials. In addition to the formal chemistry described above, the presence of oxygen and moisture also influences cross-link density and foam structure. It is chain extender for vinyl-addition silicones, enabling low viscosity, high elongation formulations. DMS -H31 is used in encapsulant applications.

DMS -H21 by Gelest (Mitsubishi Chemical) is poly (dimethylsiloxane), hydride terminated. It undergoes three main classes of reactivity: hydrosilylation, dehydrogenative coupling and hydride transfer. The silanol terminated polydimethylsiloxanes react with hydride functional siloxanes to produce foamed silicone materials. In addition to the formal chemistry described above, the presence of oxygen and moisture also influences cross-link density and foam structure. It is chain extender for vinyl-addition silicones, enabling low viscosity, high elongation formulations. DMS -H21 is used in encapsulant applications.