The structure of fatty amine polyglycol ether surfactants is illustrated in the diagram below. The hydrophilic moiety is composed of hydroxyl groups and ether linkages. However, the alternation of hydroxyl groups and ether linkages differs from the predominantly ether linkage structure of polyoxyethylene ether non-ionic surfactants. When dissolved in water, fatty amine polyglycol ether surfactants exhibit enhanced water solubility compared to the latter. This is attributed to the fact that, in addition to forming weaker hydrogen bonds through the oxygen atoms in the ether linkages with hydrogen atoms in water, they can also interact with water through hydroxyl groups. Consequently, fatty amine polyglycol ether surfactants achieve good water solubility with a lower degree of ethoxylation, making their hydrophilicity significantly stronger than that of polyoxyethylene ether surfactants. Additionally, the surfactants possess an organic amine structure, endowing them with characteristics of both non-ionic and cationic surfactants. At lower degrees of ethoxylation, cationic surfactant properties, such as acid resistance and limited alkaline tolerance, are evident. As the degree of ethoxylation increases, non-ionic characteristics become more prominent. In alkaline solutions, they no longer precipitate, and their surface activity remains intact. The increase in non-ionic characteristics and decrease in cationic properties result in reduced incompatibility with anionic surfactants, allowing for their combination.
The chemical structural formula for fatty amine polyglycol ether surfactant
The diverse properties of fatty amine polyglycol ether surfactants are reflected in their different degrees of ethoxylation: at lower degrees, cationic surfactant characteristics are observed, enhancing solubility at low temperatures and providing effective washing capabilities over a wide temperature range. At higher degrees of ethoxylation, non-ionic characteristics prevail, preventing precipitation in alkaline solutions and maintaining surface activity. With increased non-ionic characteristics and decreased cationic properties, these surfactants, when co-formulated with anionic surfactants, significantly reduce surface tension, improving emulsification and wetting abilities. Similar to polyoxyethylene chains, their hydrophilic nature and steric hindrance effectively inhibit the precipitation or coagulation of detergents. Additionally, fatty amine polyglycol ether surfactants exhibit certain softening and antistatic properties, addressing tactile issues in fiber products after washing.
Fatty amine polyglycol ether surfactants not only exhibit excellent emulsifying properties as non-ionic surfactants but also possess some bactericidal and disinfectant properties due to their cationic structure. As a "multi-functional" mixed surfactant, they enhance the adaptability of pesticide microemulsions to temperature variations. The efficiency of these surfactants in forming O/W microemulsions is high, allowing for a significant reduction in surfactant dosage and cost.
Fatty amine polyglycol ether surfactants, through the formation of a continuous water film on fiber surfaces via hydroxyl group bonding and hydrogen bonding with water molecules, exhibit excellent hygroscopic and conductive properties. They also reduce fiber friction and static electricity generation by forming a hydrophobic oil film on fiber surfaces, resulting in a soft and smooth effect. Moreover, the hydrophilic and hydrophobic parts of fatty amine polyglycol ether surfactants, similar to fatty amine polyoxyethylene ether, exhibit stronger hygroscopic and conductive properties due to the inclusion of glycerol in the ethoxylation process, rather than ethylene oxide. Additionally, the toxicity and irritation of fatty amine polyglycol ether surfactants are significantly lower than those of cationic surfactants, making them a promising candidate for superior antistatic agents.
In the process of preparing fatty amine polyglycol ether surfactants using glycerol as the starting material, the alternating arrangement of ether linkages and hydroxyl groups in the structure avoids the generation of dioxane, resulting in higher safety compared to polyoxyethylene ether surfactants. The significant presence of hydroxyl groups in fatty amine polyglycol ether surfactants enhances their hydrophilicity, reduces irritation, and makes them gentler on the skin. Therefore, fatty amine polyglycol ether surfactants are suitable for formulating mild personal care products, especially for infants and toddlers.
Research has shown that fatty amine-type non-ionic surfactants exhibit favorable effects in the surface treatment of phthalocyanine green pigments. The efficacy of this treatment arises from the ability of these surfactants to form hydrogen bonds with the nitrogen on the surface of the phthalocyanine green pigment, utilizing one hydrogen (H) from one hydroxyl (OH) and one nitrogen (N) from the amine group. This interaction leads to the adsorption of the surfactant onto the pigment surface, creating an adsorption layer with the hydrophobic carbon-hydrogen chains, forming a protective coating. The resulting coating effectively prevents pigment particle aggregation during the drying process, inhibiting the continued growth of crystals and yielding smaller, finely crystallized pigment particles.
In organic media, the pigment, after undergoing this treatment, rapidly forms a solvated film due to the favorable compatibility between the carbon-hydrogen chains and the organic medium. This solvated film facilitates the dispersion of pigment particles, preventing coagulation when particles come into close proximity. The effectiveness of this action increases with the growth of the carbon-hydrogen chains and the thickening of the solvated film, promoting finer particle sizes and a narrower particle size distribution.
Fatty amine polyglycol ether surfactants, characterized by stronger hydrophilicity, are capable of forming thicker hydration films. Consequently, pigments treated with these surfactants are more easily dispersed in water, and the particles are smaller. This suggests a promising application prospect for the surface treatment of phthalocyanine green pigments using fatty amine polyglycol ether surfactants.