Amino silicone oil is a fundamental component specifically used in textile softening agents. It offers excellent adsorption, compatibility, and easy emulsification properties. When processed with mixers or homogenizers, amino silicone oil can be readily emulsified by suitable surfactants into stable, transparent microemulsions. It can be used alone or combined with other silicones or organic softeners to formulate specialized softening agents suitable for softening various types of textiles. 
Introduction
Amino silicone oil is a fundamental component specifically used in textile softening agents. It exhibits excellent adsorption, compatibility, and emulsifiability. When processed with mixers or homogenizers, amino silicone oil can be easily emulsified into stable, transparent microemulsions using suitable surfactants. It can be used alone or blended with other silicones or organic softeners to create customized softening agents suitable for various textiles. The amine value of amino silicone oil ranges from 0.2 to 1.2; higher amine values result in better softness and smoothness, but also increase the risk of yellowing. 
Preparation method 
Aminoalkyl silane is prepared by reacting cyanopropyl methyl dichlorosilane (or alkoxy silane) and chloropropyl methyl dichlorosilane (or alkoxy silane) with diethylamine, followed by hydrolysis and copolymerization with cyclic tetrasiloxane. 
Application
Amino silicone oil, when emulsified with an emulsifier, forms a commonly used emulsion as a textile finishing agent that significantly improves softness, wrinkle resistance, elasticity, and tear strength. It is also applied as a polishing agent for instruments and furniture, paper treatment agent, coating antifreeze, and rust and corrosion inhibitor for metals. Additionally, amino silicone oil serves as an additive in hair care products such as hair oils and hair waxes, making hair soft and shiny. 
Features 
Excellent softness, smoothness, and consistent texture. 
Enhance the fabric's tear strength and wrinkle resistance. 
Improve the fabric's elasticity. 
Water and dry clean resistant. 
Easy to emulsify, can form stable microemulsions. 
Excellent compatibility, compatible with most organic softeners and other textile auxiliaries. 
Select 
Under normal circumstances and according to standard requirements, the selection of amino silicone oil for different fabrics is as follows: 
① For pure cotton and blended knitted or woven fabrics, which are primarily soft to the touch, amino silicone oil with a 0.6 amine value is recommended; 
② Pure polyester fabric, primarily with a smooth hand feel, can use amino silicone oil with an ammonia value of 0.3; 
③ Silk knits and woven fabrics primarily require a smooth hand feel with higher gloss requirements; thus, amino silicone oil with an amine value of 0.3 is mainly selected, combined with other softening agents to enhance luster. 
④ Wool and its blends require a soft, smooth, and elastic hand feel with minimal color and luster variation. A blend of amino silicone oils with 0.6 and 0.3 amine values can be selected; for certain types, a combination with a lubricant may enhance elasticity and gloss. 
⑤ Cashmere sweaters and cashmere fabrics have a superior overall hand feel compared to woolen fabrics, making high-concentration blended products a suitable choice. 
⑥ Nylon socks, primarily featuring a smooth feel, should use high-elasticity amino silicone oil; 
⑦ Acrylic Raschel blankets and acrylic or blended yarns, primarily requiring softness with high elasticity demands, can use amino silicone oil with a 0.6 amine value to meet both softness and elasticity requirements; 
⑧ Linen fabrics (flax, ramie) are primarily smooth, so amino silicone oil with a 0.3 ammonia value is mainly selected; 
⑨ Rayon and viscose fabrics are primarily soft to the touch, so an amino silicone oil with a 0.6 ammonia value can be selected; 
⑩ Polyester fabric with reduced alkali content, primarily aimed at enhancing fabric hydrophilicity, can be treated with polyether-modified silicone oil (CGF), which is synthesized through hydrosilylation between methyl hydrogen silicone oil and polyethers such as polyethylene glycol or polypropylene glycol bearing unsaturated end groups. However, the softness of the fabric is relatively poor. New polyether-modified silicone oils introduce reactive epoxy groups onto the siloxane chain, thereby improving both fabric hand feel and durability. 
Amino silicone softeners are substances that enhance the softness of fiber materials. High-performance softeners can also impart special hand-feel to fibers, give products distinctive finishing styles, improve quality and added value, and increase garment comfort. Industrially used softeners can be classified into four main types based on their primary active ingredients: oil-based, surfactant-based, reactive, and polymer-based. The first three types were predominantly used in earlier periods, but since the 1970s, the development and application of polymer-based softeners have rapidly gained attention and become the mainstream in softening finishing. Among polymer-based softeners, organosilicone softeners—primarily composed of polyorganosiloxanes—exhibit the best performance and highest production volume. Statistics indicate that approximately 150,000 tons of siloxane are globally used annually in textile finishing auxiliaries, with softeners accounting for 70% to 80% of this amount. 
Polyether silicone oil 
Silicone oils containing polyoxyethylene or polyoxypropylene groups, or fatty alcohol polyoxyethylene-polyoxypropylene ether groups on their side chains are known as polyether-modified silicone oils. These were developed to address the shortcomings of first- and second-generation organosilicone softeners, such as poor shear stability of silicone emulsions during use and low moisture absorption in finished fabrics. Polyether-modified silicone oils can be synthesized either by an addition reaction between hydrogenated silicone oil and unsaturated polyether under platinum catalysis, or through ring-opening reactions between epoxy silicone oils and polyethers, or esterification reactions between hydroxyl-modified silicone oils and bifunctional carboxylic acids or polyethers. The introduction of hydrophilic polyether side chains increases the water affinity of the silicone oil, sometimes transforming it from hydrophobic to water-soluble. As a result, these oils do not suffer from emulsion breaking or oil floating during application. Moreover, the incorporation of polyether groups enhances the moisture absorption, antistatic properties, and stain release of treated fibers or fabrics, making polyether-modified silicone oils widely used in cosmetics and shampoos. However, these oils generally exhibit weak self-crosslinking film-forming ability and poor adhesion to fibers. This issue can be resolved by introducing or retaining some epoxy groups along the silicone backbone during synthesis. For example, silicone oils with structure (I) not only retain all the advantages of polyether-modified silicone oils but also provide softer, more wrinkle-resistant, wash-durable, and highly hairy-finished textiles. Therefore, polyether/epoxy silicone oils represent the most widely used and effective class of reactive organosilicone softeners prior to the successful development of cationic amino silicone softeners. 
Performance Features Structure 
Structurally, polyorganosiloxanes have the following characteristics: 
(1) The main chain consists of inorganic Si—O—Si bonds, while the side chains are organic groups, making it a typical semi-inorganic, semi-organic polymer. 
(2) The bond angle (∠SiOSi) of the Si—O—Si bonds in the main chain ranges from 130° to 145°, with a bond length of 0.163 nm to 0.164 nm and a bond energy of 367.8 kJ/mol. Compared to carbon oxides in the same group (bond angle ∠COC = 108°, C—O bond length = 0.142 nm, bond energy = 357.4 kJ/mol), the polysiloxane main chain exhibits larger bond angles, longer bond lengths, and higher bond energy. 
(3) The bond angle of the side chain C—Si—O is 160°, and the C—Si bond length is 0.188 nm, resulting in a low activation energy of only 8 kJ/mol required for rotation of the methyl group around the Si—O bond. 
(4) The dipole-dipole interactions between the Si—O bonds in the polysiloxane backbone and the interactions among the side-chain Si—CH₃ groups cause polyorganosiloxane molecules to exist in a specific α-helical structure with methyl groups facing outward and siloxane bonds oriented inward. This unique structure results in weak intermolecular forces, large molar volume, and low surface tension. 
(5) Polydimethylsiloxanes with side groups such as Si—H, Si—OR, or Si—OH are all reactive. 
Performance 
Polyorganosiloxane molecules have the following characteristics: 
(1) Excellent electrical insulation, flame retardancy, and weather resistance; 
(2) Ideal physical and chemical inertness, non-toxicity, and no pollution to the ecological environment; 
(3) Low glass transition temperature, excellent resistance to high and low temperatures, and low viscosity-temperature rheological behavior; 
(4) Easy spreading, film formation, defoaming, hydrophobicity, and lubricity due to low surface tension. 
Additionally, modified silicone oils formed by replacing some of the methyl groups in polydimethylsiloxane with other organic groups such as polyether, epoxy, hydroxyl, thiol, carboxyl, phosphate ester, amino, or fluorocarbon groups not only retain the aforementioned general properties but also exhibit additional characteristics imparted by these organic groups. Therefore, when polyorganosiloxane emulsions are used in pad-finishing treatments for fabrics, they effectively isolate fibers, preventing direct fiber-to-fiber contact, while also reducing the surface friction coefficient of fibers, enabling easier relative sliding and thus enhancing softness. 
Fabrics finished with polyorganosiloxane emulsion have the following advantages: 
(1) Comfortable hand feel, ideal softness, smoothness, elasticity, and body; excellent wrinkle resistance and drape. 
(2) Certain water resistance and good breathability; 
(3) The fabric's abrasion resistance and tear strength are improved, and its sewability is enhanced. 
(4) Blended or synthetic fabrics have cotton-like, linen-like, wool-like, or silk-like effects; 
(5) Improves dimensional stability and shrink resistance of cotton, linen, wool, silk, and other fabrics.