Because of its excellent structural properties, silicone oil is widely used in textile soft finishing. Its main varieties include first-generation hydroxy silicone oil, hydrogen-containing silicone oil, second-generation amino silicone oil and third-generation multi-stage silicone oil. With the improvement of people's demand, silicone oil has been continuously improved for decades.
1. Hydroxy Silicone Oil
The main structure of hydroxy silicone oil is a linear polymer with hydroxyl main chain as silicon at both ends. The common synthesis method is made by hydrolysis of dimethyldichlorosilane. Its surface energy and polarization degree are low and the antioxidant capacity of the substrate surface is weak. The traditional application of hydroxy silicone oil needs high molecular weight to produce better application effect. Therefore, the molecular weight of hydroxy silicone oil which is usually used for the division after the fine method is a polymer with high molecular weight. The disadvantage is that due to the low surface energy of silicone oil and the water dispersibility is very poor, the resulting emulsification requires a higher proportion of emulsifier and a highly dispersed shear dispersant to disperse it into a better microemulsion. However, the stability in the process is still poor. In the long run, emulsification stratification will still occur.
2. Hydrogen-containing Silicone Oil
The main structure of hydrogen-containing silicone oil is polysiloxane. The side groups of silicone chain are evenly distributed with silicon-hydrogen groups. The common synthesis method is methyl hydrogenolysis polyoctyl polycrystalline and hydrogen-containing silicon-oxygen ring-opening polymerization. Because of poor stability of silicon-hydrogen bond and easy dehydrogenation, it is easy to adsorb with polar group and react with textile materials, so it has good adsorption performance and good application performance in cellulose fiber and protein fiber. But its effect on chemical fiber is not good. Like hydroxy silicone oil, its emulsifying property and stability are not good. If the hydrogen content is too high, it will easily lead to high hydrogen content, which will cause certain risks in the high temperature environment of the setting environment.
3. Amino Silicone Oil
The main structure of amino silicone oil is to form a kind of polysilane with amino polysilane as transverse direction after polymerization of polysiloxane, which is formed because amino acids have better adsorption and binding ability to fabric and better polarity, greatly improving the soft property and water dispersion of polysilane. Especially in the application of fiber fabrics, it has excellent effect. By adjusting the ammonia value, the type of aminosilane coupling agent and the molecular weight of amino silicone oil, rich application effect can be achieved. However, because its main chain structure is still siloxane structure, its emulsifier performance still needs more emulsifiers to achieve better emulsifying effect. In addition, the amino silicone oil has high ammonia activity and is on the side group, so it is absorbed by the fabric and difficult to clean. Sometimes in the fabric dyeing process, cleaning wrinkles and silicone oil spots are hard to remove. Its emulsifying ability to resist hard water and alkaline water is weak.
4. Insert Silicone Oil
The main structure of silicone oil in the ninth stage is that the hydrophilic property and emulsification of silicon is improved by forging some hydrophilic polyester chains, forging with amino chains and embedding forging copolymerization. By adjusting the proportion, type and molecular weight of three-chain forging, a large number of products can be mixed. Through its better hydrophilic permeability, it is more suitable for the soft finishing of chemical fiber fabrics with better decolorization. Yellowing is not easy to occur. In today's modification study, it is also a very popular softener category.