Amino silicone oil is primarily used as a softening agent in the treatment of clothing fabrics. Its polar amino groups can interact with hydroxyl and carboxyl groups on the fiber surface, causing the silicone oxane main chain to adsorb onto the fiber surface in a directed manner, thereby reducing the friction coefficient between fibers and making it easier for the fibers to slide relative to each other, exhibiting a soft texture. However, amino silicone oil may also cause yellowing of clothing fabrics, and its mechanism of action is complex and multifaceted.

On the one hand, the higher the amine value of amino silicone oil, the better its softness and smoothness typically are, but the more severe the yellowing phenomenon may be. This is because the presence of numerous amino and active hydrogen atoms makes it easy to generate azo groups (--N-N--) under the influence of heat, moisture, and ultraviolet light, which are the main cause of fabric yellowing. This diamine structure has a synergistic effect, accelerating oxidation and facilitating the formation of chromophores, leading to yellowing.

On the other hand, the yellowing phenomenon is also related to the viscosity of amino silicone oil, the choice of emulsifiers, and the type of fabric being treated. For example, in some cases, amino silicone oil can provide good hand feel and low yellowing when used on pure cotton fabrics, whereas on pure polyester fabrics, although higher amino content may result in better hand feel, the yellowing does not show a clear pattern.

Furthermore, the yellowing of clothing fabrics may be influenced by various other factors, such as light-induced yellowing and phenolic yellowing. Light-induced yellowing is caused by exposure to sunlight or ultraviolet light, resulting in surface color yellowing, while phenolic yellowing is caused by chemical reactions between certain components in the fabric raw materials and nitrogen oxides in the air, leading to material yellowing.

Therefore, when using amino silicone oil to treat clothing fabrics, it is necessary to comprehensively consider its softness, yellowing tendency, and other possible influencing factors to select the most suitable treatment plan. At the same time, attention should also be paid to the quality of amino silicone oil, emulsification technology, and its use in combination with other textile auxiliaries to ensure that the treated clothing fabrics have excellent softness and low yellowing tendency.