Hydroxysilicone oil, also known as dimethyl hydroxysilicone oil, is a type of organic silicon compound with a specific chemical structure. Its structural formula is
HO[(CH3)2SiO]nH， Manifested as a linear polymer with repeated silicon oxygen bonds as the main chain, methyl as the side group, and hydroxyl terminated. Hydroxysilicone oil has various excellent properties and is widely used in multiple fields.

1、 Physical and chemical properties
Hydroxysilicone oil typically appears as a colorless, transparent, odorless, and tasteless oily liquid in its physical form. It is soluble in organic solvents such as carbon tetrachloride, benzene, chloroform, ether, and toluene, but insoluble in water and ethanol. It is worth noting that low viscosity hydroxy silicone oil has a certain solubility in water. Its viscosity can range from very small to tens of thousands of pascals per second, with hydroxyl content ranging from a few tens of thousands to over ten percent. The typical viscosity of hydroxyl silicone oil is ≤ 40 millipascals per second (25 ° C), and its refractive index is in the range of 1.4000~1.4100 (25 ° C).

2、 Preparation method
There are various methods for preparing hydroxy silicone oil, mainly including the following approaches:
1. Silane hydrolysis method: It is synthesized by reacting silane with water. Sodium hydroxide (NaOH) or potassium hydroxide (KOH) is commonly dissolved in water to prepare a solution containing hydroxide ions, which is then reacted with raw materials such as dimethyldichlorosilane to produce hydroxy silicone oil.
2. Ring opening degradation method: It is formed by the ring opening and water degradation of octamethylcyclotetrasiloxane (D4) under the action of acid or base.
3. Silicone rubber degradation method: It is formed by adding water and catalyzing the degradation of silicone rubber in an autoclave.
4. Degradation method of high molecular weight polydimethylsiloxane: It is obtained by catalytic water addition with potassium hydroxide under high pressure.

3、 Main purpose
Hydroxysilicone oil has shown significant application value in multiple fields due to its unique chemical structure and properties
1. Silicone rubber processing: Low viscosity hydroxy silicone oil is an excellent structural control agent in silicone rubber processing, which can replace diphenylsilanol and simplify the process
Art, improve process performance.
2. Fabric finishing: Hydroxysilicone oil is widely used in fabric finishing, which can significantly improve the softness, smoothness, and sewing performance of fabrics, while endowing fabrics with waterproof and water repellent properties. In the process of fabric finishing, hydroxyl silicone oil needs to be prepared into lotion to improve its stability and adaptability.
3. Leather and paper processing: As a waterproof, softening, and anti sticking agent for leather and paper, hydroxyl silicone oil can effectively improve the surface properties of these materials.
4. Other fields: Hydroxysilicone oil is also widely used in coatings, electronics and electrical, biomedicine, food, and personal care. In terms of polyurethane modification, the copolymerization of hydroxyl silicone oil and polyurethane can overcome the defects of single polymers and endow the copolymer with excellent properties such as flexibility, water resistance, and biocompatibility.

4、 Market prospects
With the advancement of technology and the development of the industry, the market demand for hydroxyl silicone oil continues to grow. Especially in high-end textiles, functional materials, and emerging application fields such as biomedicine and electronics, the application prospects of hydroxyl silicone oil are very broad. It is expected that in the coming years, the global market for dimethyl hydroxy silicone oil will maintain a stable growth trend, and the Chinese market will also play an increasingly important role.
In summary, hydroxyl silicone oil, as a high-performance organic silicon compound, has demonstrated significant application value and development potential in multiple fields. With the continuous advancement of technology and the continuous expansion of the market, the application prospects of hydroxyl silicone oil will be even broader.