Synthesis
3-Glycidoxypropyltrimethoxysilane is synthesized by hydrosilylation of trimethoxysilane with allyl glycidyl ether. The reaction equation is as follows:
This hydrosilylation is a coordination addition, and its reaction mechanism is the Chalk-Harrod mechanism (see figure below). This reaction mechanism uses traditional oxidative addition and reductive elimination steps to explain how the hydrosilylation proceeds. The reaction process consists of three steps, which can be illustrated by the following reaction equation:
That is, the first step: hydrosilane oxidative addition to form a six-coordinate intermediate complex (1); the second step: hydrogen migration to obtain a 6-complex (2); the third step: reductive elimination to obtain the addition product (3).
[1] Jiang Zhiqi, Zhu Xiaoying, Wang Yugang, et al. [J]. Zhejiang Chemical Industry, 2011, 42(08):10-14.
Silane Coupling Agents KH-560
KH-560 is the first widely used coupling agent and has been used for 40 years. One end of its structure with reactive groups such as amino and vinyl, can react with epoxy, phenolic, polyester and other synthetic resin molecules. The other end is alkoxy (such as methoxy, ethoxy etc.) or chlorine atoms which is connected with silicon. These groups can be transformed into silanol in the hydrolysis in water solution or damp air. And the formed silanol is able to react with surface hydroxyl of glass, minerals and inorganic filler. Therefore, silane coupling agent is commonly used in silicate-filled epoxy, phenolic, polyester resin and other systems. In addition, it can also be used for FRP production, in order to improve its mechanical strength and resistance to wet environment. The organic groups of the silane coupling agent are selective about the reaction of the synthetic resin. Generally, these organic groups lack sufficient reactivity with synthetic resins such as polyethylene, polypropylene and polystyrene, and thus the coupling effect for them is poor. In recent years, new varieties of silane coupling agents with better coupling for polyolefins have been developed, but are limited in cost and other properties and are not yet widely used.
Silane coupling agent is also known as silane treatment agent. Its general formula is Y (CH2) nSiX3. Wherein n is an integer of 0 to 3; X is a hydrolyzable group such as chlorine, methoxy, ethoxy and acetoxy; Y is an organic functional group such as a vinyl, an amino, an epoxy group, a methacryloyloxy group and sulfydryl.
Physicochemical Properties
Colorless transparent liquid;
Soluble in a variety of organic solvents;
Easy to hydrolysis;
Able for condensation to form polysiloxanes;
Easy to polymerize in the presence of overheating, light and peroxide.
Molecular Structure
Fig: Molecular structure
Uses
3-Glycidoxypropyltrimethoxysilane is an epoxy-functional silane, it is a clear, light straw liquid. 3-Glycidoxypropyltrimethoxysilane may be used as a coupling agent in polysulfide and polyurethane caulks and sealants, in mineral-filled or glass-reinforced thermosets and thermoplastics, and in glass roving size-binders. It is particularly employed as an adhesion-promoting additive in waterborne systems, e.g. improving the adhesion of acrylic latex sealants.
Applications:
- 3-Glycidoxypropyltrimethoxysilane may improve dry and wet strength in cured composites reinforced with glass fiber rovings
- Enhance wet electrical properties of epoxy-based encapsulate and packaging materials.
- Eliminate the need for a separate primer in polysulfide and urethane sealants.
- Improve adhesion in waterborne acrylic sealants and in urethane and epoxy coatings.
Application
- It is mainly used in unsaturated polyester composites to improve the mechanical properties, electrical properties and light transmission properties of the composites, especially to improve their performance in wet environment.
- In wire and cable industry, when used to treat EPDM system stuffed by pottery clay and crosslinked by peroxide, it can improve consumption factor and specific inductance captance.
- Used for its copolymerization with monomers like vinyl acetate and acrylic acid or methacrylic, to form the polymers widely used in coatings, adhesives and sealants, providing excellent adhesion and durability.
Handling and Storage
Normal measures for preventive fire protection.
Keep container tightly closed in a dry and well-ventilated place. Recommended storage temperature is 2-8 °C.
Fire-fighting measures
Flammable properties
Flash point: 135 °C (275 °F)-closed cup
Ignition temperature: 400 °C (752 °F)
Suitable extinguishing media
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special protective equipment for fire-fighters
Wear self-contained breathing apparatus for fire-fighting if necessary.
Toxicological Information
Acute toxicity: LD50 Oral-rat-8,030 mg/kg
LD50 Dermal-rabbit-4,248 mg/kg
Irritation and corrosion:
Eyes-rabbit-Mild eye irritation
Chemical Properties
Colorless transparent liquid
Uses
Pre-treatment of carbon steel with 3-(Glycidoxypropyl)trimethoxysilane enhances the dry and wet adhesion while reducing the cathotic disbondment rate of an epoxy coating
Uses
(3-Glycidoxypropyl)trimethoxysilane is used in the production of carbon steel and its pre treatment favors the dry and wet adhesion of epoxy coating. It is also used to prepare epoxy-functionalized silica nanoparticles, which gives a reactive surface for one-step and high-density protein immobilization. It serves as a coupling agent and adhesion promoter.
General Description
(3-Glycidyloxypropyl)trimethoxysilane (GPTMS) is a bifunctional organosilane with three methoxy groups on one side and an epoxy ring on the other. The methoxy groups bind well with glass substrates creating a 3D matrix. The epoxy group is reactive with amides, alcohols, thiols and acids. GPTMS is highly reactive in water and can be used as a linking agent between the surface of the silica and the polymeric matrix.
Flammability and Explosibility
Not classified
