End-side hydrogenated silicone oil (i.e. α,ω-dihydrogen-terminated polymethylhydrogensiloxane, usually with the chemical formula H-(Si(CH₃)(H)O)ₙ-H) is a type of silicone polymer containing active silicon-hydrogen bonds (Si-H) at both ends of the molecular chain and/or on the side chains. Its highly reactive Si-H bonds give it a wide range of application value, especially in the fields of cross-linking, modification and functional materials. The following is a detailed analysis of its core application areas:
1. Silicone rubber crosslinker
Action mechanism:
The Si-H bond in the end-side hydrogenated silicone oil can react with the vinyl silicone oil (containing CH=CH₂) under the action of platinum catalyst (Pt) to form a three-dimensional network structure, achieving room temperature or heating curing.
Application scenarios:
Addition liquid silicone rubber (LSR): used for medical devices (such as catheters, nipples), electronic packaging (LED potting glue), etc., with the characteristics of non-toxicity, high temperature resistance, good elasticity, etc.
High temperature vulcanized silicone rubber (HTV): as an auxiliary crosslinker, improves vulcanization efficiency and mechanical properties.
2. Textile finishing agent
Hydrophobic/soft finishing:
Si-H bonds react with hydroxyl groups (-OH) on the fiber surface under the action of catalysts (such as titanate) to form a hydrophobic film, giving the fabric waterproof, anti-fouling and anti-wrinkle properties.
Combined with amino silicone oil, it can enhance the soft feel and is used for high-end clothing and home textile fabrics.
Flame retardant enhancement:
Hydrogen-containing silicone oil is used in conjunction with flame retardants (such as phosphorus compounds) to form a silica protective layer through the thermal decomposition of Si-H bonds to improve flame retardancy.
3. Surface treatment and coating
Glass/ceramic anti-fog coating:
Through Si-H bond reaction with the hydroxyl group on the substrate surface, a strong siloxane film is formed to prevent water vapor condensation (such as car rearview mirrors, glasses).
Metal anti-corrosion:
Form a hydrophobic protective layer on the metal surface to block water and oxygen contact (need to be used with a coupling agent).
4. Personal care and cosmetics
Film formers and conditioners:
Used in conditioners and shampoos, the Si-H bonds are hydrolyzed to form a siloxane film, which improves the smoothness and gloss of hair.
Used as a hydrophobic agent in sunscreen to enhance water resistance.
Safety: Low molecular weight components need to be controlled to avoid skin irritation.
5. Electronic and optoelectronic materials
Packaging and bonding:
As a crosslinking agent for encapsulation glue of LED and photovoltaic modules, resistant to ultraviolet light and high temperature (above 180°C).
Compounded with conductive filler (silver powder) for conductive glue.
Optical devices:
Prepare highly transparent silicone lenses or optical waveguide materials through Si-H bond curing.
6. Special material modification
Plastic toughening:
Blending with polyolefins (such as PP) to improve compatibility and impact resistance through Si-H bond grafting.
Paper anti-sticking:
Coated on the surface of release paper as the release layer of silicone pressure-sensitive adhesive (such as label backing paper).
7. Other emerging fields
New energy batteries:
Used in lithium-ion battery separator coating to improve high temperature resistance and electrolyte wettability.
3D printing:
As a cross-linking component of photocurable silicone resin, it can achieve high-precision flexible device printing.
Key advantages and challenges
Advantages:
High reactivity (Si-H bond), low viscosity (easy to process), excellent weather resistance.
Environmentally friendly (solvent-free products comply with RoHS/REACH).
Challenges:
The amount of catalyst must be strictly controlled (platinum catalysts are expensive and easily poisoned).
Storage stability (Si-H bonds are easily hydrolyzed and require moisture-proof sealing).
