Hydrogen-terminated silicone oil is a compound composed of a polysiloxane backbone and Si-H bonds on its end groups. These Si-H bonds are highly reactive and can react with a variety of compounds, such as addition reactions with organosilicon compounds and crosslinking reactions with hydrogen-containing polymers. This high reactivity makes hydrogen-terminated silicone oil an ideal starting material for the synthesis of organosilicon-modified block or graft copolymers.
The preparation of hydrogen-terminated silicone oil typically involves two main steps: first, the synthesis of polysiloxanes, and second, end-grouping treatment. Polysiloxanes can be synthesized using various methods, such as direct methods, indirect methods, or ring-opening polymerization. During synthesis, selecting appropriate end-capping agents and catalysts is crucial, as it directly affects the molecular weight of the final product and the Si-H bond content of the end groups. Commercially available catalysts mainly include concentrated sulfuric acid, solid catalysts (rare earth cation exchange resins), and activated clay. The synthesized polysiloxanes are then end-grouped to introduce Si-H bonds, thereby obtaining hydrogen-terminated silicone oil.
Hydrogen-terminated double-headed method: Add DMC or D4 and tetramethyldihydrodisiloxane (hydrogen-terminated double-headed) to a reactor, control the temperature at 30-35℃, start stirring and add catalyst, react at constant temperature for 6-8 h, add sodium carbonate to neutralize to neutral, and finally add anhydrous calcium chloride and stir for 0.5 h, filter to obtain hydrogen-terminated silicone oil.
Good plasticizing properties: Due to the unique molecular structure of hydrogen-terminated silicone oils, they can effectively improve the flexibility and processing properties of other materials, making them easier to mold and process. Excellent hydrosilylation reactivity: The Si-H bonds of hydrogen-terminated silicone oils can undergo addition reactions with a variety of organic compounds, making them a key starting material for the synthesis of organosilicon-modified block or graft copolymers.
Basic intermediates in hydrosilylation reactions: Hydrogen-terminated silicone oils are important intermediates in hydrosilylation reactions, through which various high-performance organosilicon materials can be synthesized.
Key intermediates in block copolymerization reactions: In the synthesis of block copolymers, hydrogen-terminated silicone oils serve as important intermediates, reacting with other polymers to form new materials with special properties.
Chain extenders for addition-type liquid silicone rubbers: In the production of liquid silicone rubber, hydrogen-terminated silicone oils can be used as chain extenders to improve the molecular weight and mechanical properties of the product.
Crosslinking agents for addition-type heat-cured silicone rubbers: Hydrogen-terminated silicone oils act as crosslinking agents in heat-cured silicone rubbers, improving the material's thermal stability and mechanical strength.
Waterproofing agents and softeners: Hydrogen-terminated silicone oils can be applied to the treatment of fabrics, leather, and other materials, imparting excellent waterproofing properties and a soft feel.
Modification of plastic resins: In the production of plastic resins, hydrogen-terminated silicone oils can be used as modifiers to improve the heat resistance, weather resistance, and mechanical properties of plastics.
