Potassium Fatty Acid Soaps: Structure and Formulation Applications—Production Processes, Alkalinity, Foam Control, and Low-Foam Cleaning

1 Potassium fatty acid soaps are a class of potassium salts of fatty acids

Potassium fatty acid soaps are potassium salts formed by the reaction of long-chain fatty acids with potassium hydroxide. Their basic structure can be represented as:

RCOO⁻K⁺

Here, R represents the hydrocarbon chain of the fatty acid, which may be derived from lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, coconut fatty acids, and other fatty acid sources. COO⁻K⁺ is the hydrophilic potassium carboxylate head group. Common ingredients used in personal care and household care products, such as potassium cocoate, potassium laurate, potassium oleate, and potassium stearate, are essentially all potassium fatty acid soaps. However, because their fatty acid chain length, degree of saturation, and composition differ, their actual performance can vary significantly.

To understand potassium fatty acid soaps, three further aspects need to be considered:

Evaluation dimension	Impact
Fatty acid source	Determines cleaning power, foam, solubility, skin feel, and low-temperature stability
Degree of neutralization	Affects free fatty acid, free alkali, pH, and irritation potential
Formulation system	Affects foam, turbidity, viscosity, hard-water tolerance, and sensory feel during use

Potassium fatty acid soaps can be used in liquid soaps, hand washes, body cleansing products, shaving creams, hard-surface cleaners, kitchen degreasers, low-foam cleaning systems, and certain industrial cleaning systems. Their value lies in the ability to tune cleaning, emulsification, wetting, foam control, and rheological performance through fatty acid composition and formulation conditions.

2 Production processes for potassium fatty acid soaps

2.1 Oil saponification process

The oil saponification process is the traditional soap-making route. Natural oils or fatty acid triglycerides undergo alkaline hydrolysis with potassium hydroxide to produce potassium fatty acid salts and glycerol:

Oil + KOH → potassium fatty acid soap + glycerol

This route is characterized by a mature processing foundation and is suitable for preparing liquid soaps, soft soaps, paste soaps, and similar products. Because oils themselves are mixtures of fatty acid glycerides, the resulting potassium fatty acid soap is usually also a mixture of potassium fatty acid salts. For example, potassium cocoate formed by saponification of coconut oil may contain potassium laurate, potassium myristate, potassium palmitate, potassium oleate, and other components.

Key control points in the oil saponification process include the degree of saponification, free alkali content, glycerol content, color, odor, transparency, and low-temperature stability. If saponification is incomplete, the system may contain a relatively high amount of unreacted oil or free fatty acids. If alkali is present in excess, the pH may become too high, irritation may increase, and formulation stability may decline.

2.2 Fatty acid neutralization process

The fatty acid neutralization process uses separated or pre-blended fatty acids as raw materials and neutralizes them with potassium hydroxide to form potassium fatty acid soaps:

Fatty acid + KOH → potassium fatty acid soap + water

Compared with the oil saponification process, the neutralization process makes it easier to control the fatty acid composition. For example, when stronger foaming and cleaning performance are desired, the proportions of lauric acid and myristic acid can be increased. When a system is intended to feel milder and more lubricious, produce lower foam, or be more suitable for oil removal and emulsification, the proportions of long-chain fatty acids such as oleic acid, stearic acid, and palmitic acid can be adjusted.

For industrial personal care and household care raw materials, the advantages of the neutralization process include controllable composition, stable batch-to-batch quality, and easier management of free alkali and active matter. For potassium fatty acid soap raw materials that require a clearly defined performance profile, such as low-foam cleaning systems, shaving cream soap bases, and hard-surface degreasing systems, the neutralization process is more suitable for precise formulation design.

3 The physicochemical properties of potassium fatty acid soaps are determined by structure

The performance of potassium fatty acid soaps is jointly determined by the lipophilic hydrocarbon chain, the carboxylate head group, the potassium ion, and the aqueous-phase conditions.

3.1 Amphiphilic structure determines cleaning and emulsifying ability

Potassium fatty acid soaps are a class of anionic surfactants. One end of the molecule is a hydrophobic hydrocarbon chain, which can readily enter oily soil; the other end is a hydrophilic potassium carboxylate head group, which readily interacts with the aqueous phase.

When potassium fatty acid soap is added to water, the molecules orient themselves at the oil-water interface or air-liquid interface, reducing interfacial tension and allowing water to wet oily surfaces more easily. Once the concentration reaches a certain level, surfactant molecules can form micelles. The hydrophobic hydrocarbon chains aggregate in the interior, while the hydrophilic head groups face the water phase, thereby encapsulating, dispersing, and carrying away oily soil. This is the fundamental reason why potassium fatty acid soaps provide cleaning, degreasing, emulsifying, and dispersing functions.

3.2 Fatty acid chain length determines solubility, foam, and skin feel

The fatty acid hydrocarbon chain is a core structural factor affecting the performance of potassium fatty acid soaps. In general, within the common C12–C18 fatty acid soap range, shorter-chain potassium fatty acid soaps have better water solubility, faster foaming, and a more obvious cleaning feel. Longer-chain saturated potassium fatty acid soaps are more hydrophobic, have lower water solubility, and are more prone to low-temperature precipitation, turbidity, or paste-like thickening.

Fatty acid type	Common carbon chain	Performance tendency
Potassium laurate	C12	Relatively good solubility, strong cleaning power and foaming ability
Potassium myristate	C14	Good foam and cleaning power, with a noticeable soap-like feel
Potassium palmitate	C16	Lower water solubility, enhanced structure and paste-like body
Potassium stearate	C18	More likely to form paste-like or structured systems; foam is not necessarily light or airy
Potassium oleate	C18:1	The unsaturated structure provides better flowability and lubricity; commonly used in soft soaps and degreasing systems

Potassium cocoate and potassium laurate generally foam more readily. Potassium oleate, potassium stearate, or potassium soaps with a relatively high proportion of long-chain fatty acids may, in certain systems, provide controlled foam, lubricity, paste-like structure, or less persistent foam.

3.3 Potassium ions affect product form and water solubility

The counterion in a fatty acid salt also affects product form. With the same fatty acid structure, sodium salts are usually more likely to form hard soaps and are more suitable for solid soaps. Potassium salts are usually more likely to form soft soaps, paste soaps, or liquid soap systems. This is why potassium fatty acid soaps are commonly used in personal care and household care formulations to prepare liquid cleansing products. Potassium ions influence crystal packing, hydration ability, hardness or softness, and the final product form.

3.4 Krafft point affects low-temperature stability and effective cleaning

Potassium fatty acid soaps are ionic surfactants, and their solubility is affected by temperature. The Krafft point refers to the temperature range at which the solubility of an ionic surfactant reaches the critical micelle concentration and then increases sharply as temperature rises. It is a key indicator for evaluating low-temperature dissolution, micelle formation, and cleaning effectiveness.

When the use temperature is below the Krafft point of a given potassium fatty acid soap, the solubility of the surfactant molecules is insufficient, making it difficult to form micelles effectively. The product may become turbid, precipitate, thicken into a paste-like state, or show reduced cleaning power. In general, linear long carbon chains reduce water solubility and may increase the risk of poor low-temperature performance. Unsaturated structures disrupt close molecular packing, allowing some long-chain fatty acid salts to retain better flowability and solubility.

Therefore, when designing liquid personal care or household care products, it is not enough to focus only on room-temperature appearance. Low-temperature clarity, low-temperature flowability, redissolution behavior, and actual use temperature should also be considered.

4 Why potassium fatty acid soaps are alkaline

4.1 Alkalinity comes from the hydrolysis of fatty acid salts

The alkalinity of potassium fatty acid soaps is not only due to residual potassium hydroxide from production. Even when free alkali is well controlled, aqueous solutions of potassium fatty acid soaps are usually still alkaline. This is because fatty acids are weak acids, while potassium hydroxide is a strong base. The potassium fatty acid salts formed from them undergo a certain degree of hydrolysis in water, causing the system to appear alkaline.

RCOO⁻ + H₂O ⇌ RCOOH + OH⁻

Carboxylate ions interact with water and generate a small amount of hydroxide ions, so the pH of soap solutions is usually higher than neutral. Aqueous solutions of alkali metal soaps are generally alkaline. Dilute solutions commonly have a pH around 8–9, although actual personal care and household care products vary depending on concentration, fatty acid composition, free alkali, and formulation additives.

4.2 Potassium fatty acid soap systems cannot simply be adjusted to weak acidity

If a potassium fatty acid soap system is forcibly adjusted to a weakly acidic pH, the carboxylate salts will gradually convert into free fatty acids:

RCOO⁻K⁺ + H⁺ → RCOOH + K⁺

Free fatty acids have poor water solubility and can easily cause turbidity, precipitation, phase separation, foam reduction, or weakened cleaning performance. Potassium fatty acid soaps are suitable for neutral-to-alkaline or alkaline systems, rather than typical weakly acidic cleansing systems. This is also an important difference between potassium fatty acid soaps and amino acid surfactants, alkyl polyglucosides, and betaine-type surfactants. The latter can remain stable over a wider pH range, whereas the effective form of potassium fatty acid soaps is relatively more sensitive to pH.

5 Why potassium fatty acid soaps can be used in low-foam cleaning systems

5.1 Low foam is a performance outcome under specific conditions

Potassium fatty acid soaps can be used in low-foam systems. Their foam behavior is jointly determined by fatty acid composition, concentration, temperature, water hardness, electrolytes, pH, and co-surfactants. Foam formation involves at least two processes:

Process	Influencing factors
Foaming	The rate at which surfactants diffuse to and adsorb at the air-liquid interface
Foam stabilization	Drainage rate of the foam film, interfacial film elasticity, molecular arrangement, and resistance to rupture

5.2 Fatty acid chains affect foam generation and foam stability

Whether a potassium fatty acid soap exhibits low-foam characteristics first depends on the fatty acid chain. Short- to medium-chain potassium fatty acid soaps, such as potassium laurate and potassium cocoate, usually have good water solubility and can reach the air-liquid interface relatively quickly, making them more likely to generate foam. Therefore, they are often used in products that require foaming and a cleansing feel, such as hand washes, body cleansers, and liquid soaps.

Long-chain saturated potassium fatty acid soaps, such as potassium stearate and potassium palmitate, have lower water solubility and a stronger tendency toward aggregation and structuring. Under specific water quality, electrolyte, temperature, and formulation conditions, they may show slower foam generation or less persistent foam. Unsaturated potassium fatty acid soaps such as potassium oleate have double-bond structures that affect molecular packing and usually provide better flowability, lubricity, and oil-removal emulsification performance. Their foam, emulsification, and foam-control performance still need to be evaluated together with concentration, pH, water quality, temperature, and the overall formulation system.

The low-foam behavior of potassium fatty acid soaps is the result of both structure and formulation. Structure provides the foundation, while formulation conditions determine the final performance.

5.3 Hard water and electrolytes change foam behavior

The carboxylate head group of potassium fatty acid soaps is sensitive to divalent metal ions such as calcium and magnesium. In hard water, fatty acid soaps react with calcium and magnesium ions to form poorly soluble calcium fatty acid salts and magnesium fatty acid salts. This reduces the amount of soluble soap, lowers foam, and may form soap scum. On the one hand, this characteristic limits the cleaning efficiency of potassium fatty acid soaps under hard-water conditions. On the other hand, it also explains why they may exhibit low foam or unstable foam in certain systems. For household cleaning, machine washing, hard-surface cleaning, or industrial cleaning products, this issue is usually improved through chelating agents, builders, co-surfactants, or water-quality control.

5.4 The real value of low-foam applications is controlled foam

In automatic dishwashing, machine laundry, floor cleaning, spray cleaning, and certain industrial cleaning applications, excessive foam can interfere with spraying, pumping, rinsing, liquid-level detection, and mechanical efficiency. In these cases, low foam does not mean weak cleaning. Instead, the surfactant system must provide sufficient wetting, emulsification, and soil-removal performance during cleaning while avoiding the formation of large amounts of stable foam.

In such systems, potassium fatty acid soaps usually do not provide the entire low-foam performance on their own. Instead, they work together with low-foaming nonionic surfactants, builders, chelating agents, alkaline agents, solvents, or defoaming components. They can provide degreasing, emulsification, wetting, and foam-regulation functions, helping the cleaning system achieve a balance between cleaning power and foam control.

6 Functions of potassium fatty acid soaps in formulations

6.1 Cleaning and degreasing

The most fundamental function of potassium fatty acid soaps is cleaning and degreasing. The hydrophobic hydrocarbon chain enters oily soil, while the hydrophilic carboxylate head group remains compatible with the water phase, allowing oily soil to be dispersed into water and removed during rinsing. In skin cleansing, they remove sebum, sweat, and particulate dirt. In kitchen and hard-surface cleaning, they help disperse animal and vegetable fats, cooking grease, and mixed soils. In laundry and industrial cleaning, they can serve as auxiliary degreasing and emulsifying components.

6.2 Wetting and spreading

Potassium fatty acid soaps can reduce the surface tension of the aqueous phase, allowing the cleaning solution to spread more easily over skin, fabrics, tableware, floors, or metal surfaces. Wetting ability determines whether the cleaning solution can quickly contact the soil and is a prerequisite for soil removal. In low-foam cleaning, wetting is especially important. Low foam does not mean low surface activity. If the system can spread, penetrate, and contact oily soil quickly, it can still maintain effective cleaning.

6.3 Emulsification and dispersion

Potassium fatty acid soaps can disperse oily soil into smaller oil droplets, reducing the likelihood of oil re-aggregation and redeposition. Potassium fatty acid soaps are not the most stable emulsifiers for all emulsion systems, but they have practical value in cleaning formulations, especially in short-contact, rinse-off degreasing systems.

6.4 Foam control

The foam-regulating function of potassium fatty acid soaps depends on fatty acid composition. Potassium laurate and potassium cocoate can enhance foaming and the cleansing feel. Potassium oleate, potassium stearate, potassium palmitate, or mixed long-chain potassium fatty acid soaps can improve foam texture and may, in specific systems, reduce foam lightness or shorten foam persistence.

6.5 Contribution to structure and viscosity

Long-chain potassium fatty acid soaps can participate in the formation of paste-like, translucent, pearlescent, or structured systems. Here, a structured system refers to a paste-like, translucent, or high-viscosity system supported by fatty acid salt aggregates, crystals, or liquid-crystalline structures. These structures can improve product body, slip, wall-cling, and the clean feel after rinsing. In shaving creams, soap-based facial cleansing pastes, soft soaps, and certain hard-surface cleaning pastes, potassium fatty acid soaps are not only cleansing components but also important structuring components that influence product form.

6.6 Alkaline cleaning assistance

Potassium fatty acid soap systems are usually alkaline. A mildly alkaline environment helps disperse, saponify, and remove oily soils, especially saponifiable fatty soils, and is practically valuable in kitchen heavy-duty degreasing, floor cleaning, equipment cleaning, and related products. However, alkalinity also limits their usage level and application scope in products for sensitive skin, weakly acidic facial cleansing, and skin care for compromised skin barriers. Formulation design needs to balance cleaning power, pH, irritation potential, and stability.

7 Why potassium fatty acid soaps can still be relatively mild despite being alkaline

7.1 Mildness is not determined by pH alone

In actual personal care and household care products, irritation is not determined only by pH. It is also related to the following factors:

Influencing factor	Impact on mildness
Active matter concentration	The higher the concentration, the stronger the degreasing power and potential irritation
Free alkali content	Excessive free alkali significantly increases irritation
Contact time	Rinse-off products have shorter contact time and lower risk than leave-on products
Rinse-off residue	Easy rinsing and low residue help reduce irritation
Fatty acid composition	Different chain lengths and degrees of saturation affect degreasing power, skin feel, and residue
Formulation system	Amphoteric surfactants, nonionic surfactants, glycerol, polyols, and oils can improve skin feel
Application area	Hands, body, scalp, and face have different tolerance levels to cleansing-related irritation

Potassium fatty acid soaps can show relative mildness when reasonably designed. Their mildness does not come from a weakly acidic pH, but from formulation control.

7.2 Relative mildness comes from four control points

To reduce irritation in potassium fatty acid soap products, four aspects are critical.

① Control free alkali.

Excessive free potassium hydroxide can cause obvious irritation and must be controlled through neutralization endpoint management, aging, testing, and pH management.

② Control fatty acid composition.

An excessively high proportion of strongly degreasing short-chain fatty acid soaps may bring strong cleaning power and a tight afterfeel. Proper incorporation of oleic acid, stearic acid, or conditioning components can improve the after-rinse skin feel.

③ Control the formulation system.

Amphoteric surfactants, nonionic surfactants, humectants, polyols, and oil-based conditioning agents can reduce the dry, harsh feel of a single soap-based system.

④ Control the method of use.

Potassium fatty acid soaps are more suitable for products with short contact time and thorough rinsing. They are not suitable as the main surfactant in leave-on products.

7.3 Potassium fatty acid soaps follow a different logic from weakly acidic mild surfactants

Amino acid surfactants, alkyl polyglucosides, betaine-type surfactants, and synthetic detergent systems can function under conditions closer to the weakly acidic pH of the skin. Potassium fatty acid soaps, however, rely on the carboxylate form to perform their cleaning function, so the system usually needs to remain neutral-to-alkaline or alkaline. The mildness of potassium fatty acid soaps can be achieved under rinse-off conditions with appropriate concentration, controlled free alkali, moderated formulation design, and low residue.

8 Comparison with ingredients of similar structural relevance

Ingredient type	Structural characteristics	Difference from potassium fatty acid soaps	Formulation implications
Sodium fatty acid soap	RCOO⁻Na⁺	Harder; usually lower water solubility than potassium soaps; more suitable for solid soaps	The counterion affects product form and solubility
TEA fatty acid soap, where TEA refers to triethanolamine	Fatty acid salt formed with triethanolamine	Commonly used in creams, shaving products, and emulsifying systems; different skin feel and viscosity	The same fatty acid can show different performance when neutralized with different bases
Potassium laurate	C12 potassium fatty acid salt	Relatively strong solubility and foaming power	Potassium soaps are not necessarily low-foaming
Potassium oleate	C18:1 potassium fatty acid salt	More associated with soft soap, lubricity, and oil-removal emulsification	Unsaturated long chains affect flowability and foam stability
SLES	Sodium laureth sulfate	Sulfate ester salt head group; rich foam; different pH adaptability	Head-group structure determines acid/alkali tolerance and foam characteristics
LAS	Linear alkylbenzene sulfonate	Sulfonate head group; strong detergency; commonly used in detergents	Carboxylate soaps and sulfonate surfactants differ in hard-water tolerance
APG	Alkyl polyglucoside	Nonionic sugar-based head group; relatively broad pH adaptability	Low irritation, foam modulation in blends, and broad pH adaptability can be achieved through a nonionic structure
Amino acid surfactants	Contain amino-acid-derived head groups	Can be used in weakly acidic systems; softer skin feel	The logic of mildness differs from that of soap-based systems
EO/PO low-foaming nonionics	Ethylene oxide/propylene oxide polyether structure	Cloud point and low-foaming properties are often regulated through the polyether structure	Low foam can be achieved through nonionic polyether structures

9 Classification Tables of Representative Chemicals Related to Potassium Fatty Acid Soaps

Table 1 Fatty Acid Raw Materials and Fatty Acid Salts

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Unsaturated fatty acid raw material	112-80-1	O108485	Oleic Acid	Moligand™, ≥99% (HPLC)	Used for research on the preparation of unsaturated fatty acid salts such as potassium oleate and sodium oleate; suitable for evaluating the effects of double-bond structures on the flowability, emulsifying properties, lubricity, and foam stability of soft soaps
Unsaturated sodium fatty acid salt	143-19-1	S104196	Sodium Oleate	Moligand™, ≥97% (T)	Used for comparative studies of sodium soaps and potassium soaps; suitable for analyzing the effects of counterions on the solubility, emulsification behavior, soap-base form, and interfacial properties of fatty acid salts
Saturated fatty acid raw material	57-10-3	P753896	Palmitic Acid	Stearic acid ≤0.5%	Used for research on palmitate systems; suitable for analyzing the effects of carbon chain length on soap-base structure, paste body support, foam texture, and low-temperature stability
Medium-chain fatty acid raw material	143-07-7	L110736	Lauric Acid	GR, ≥99%	Used for research on the preparation of fatty acid salts such as potassium laurate and sodium laurate; suitable for evaluating the foaming, cleaning, solubility, and degreasing characteristics of short- to medium-chain fatty acid salts
Long-chain saturated fatty acid raw material	57-11-4	S754992	Stearic Acid	≥98.5% (GC), Grade I	Used for research related to potassium stearate, sodium stearate, and triethanolamine stearate; suitable for soap-based pastes, shaving systems, emulsion structures, and foam-control systems
Medium-chain fatty acid raw material	544-63-8	M108283	Myristic Acid	Moligand™, ≥98%	Used for research on the preparation of fatty acid salts such as potassium myristate; suitable for analyzing changes in foam, soap-like feel, and dissolution behavior as the carbon chain changes from lauric acid to stearic acid
Short- to medium-chain fatty acid raw material	124-07-2	O108279	n-Octanoic Acid	AR, ≥99%	Used for model studies of short- to medium-chain fatty acid salts; suitable for comparing the effects of carbon chain length on water solubility, interfacial activity, and low-temperature performance in cleaning systems
Medium-chain fatty acid raw material	334-48-5	D109192	n-Decanoic Acid	Moligand™, chemically pure (CP), ≥98%	Used for research on decanoate systems; suitable for gradient experiments on fatty acid chain length, solubility, emulsifying ability, and foam behavior
Potassium fatty acid soap	143-18-0	P100097	Potassium Oleate	Chemically pure (CP)	A typical unsaturated potassium fatty acid soap; used in research on soft soaps, degreasing, emulsification, and lubricating cleaning systems; suitable for analyzing the effects of unsaturated structures on soap-base flowability and foam behavior
Sodium fatty acid soap	822-16-2	S108362	Sodium Stearate	PharmPure™, USP	A typical long-chain saturated sodium fatty acid soap; used for comparison between sodium soaps and potassium soaps; suitable for studying the effects of counterions on hard-soap structure, solubility, and system form
Potassium fatty acid soap	593-29-3	P112436	Potassium Stearate	AR, ≥98%	A typical long-chain saturated potassium fatty acid soap; used in paste soaps, shaving soap bases, structured cleaning systems, and foam-regulation studies
Potassium fatty acid soap	13429-27-1	P768713	Potassium Myristate	≥99%	A C14 potassium fatty acid soap; used to compare the differences in solubility, foam, and soap-like feel among potassium laurate, potassium myristate, and potassium stearate
Potassium fatty acid soap	2624-31-9	P1062057	Potassium Palmitate	≥98%	A C16 potassium fatty acid soap; used for research on palmitate systems; suitable for analyzing the paste structure, foam texture, and low-temperature stability of long-chain potassium fatty acid soaps
Potassium fatty acid soap	10124-65-9	P731198	Potassium Laurate	≥98%	A C12 potassium fatty acid soap; used for research on foaming, cleaning, wetting, and micellar behavior; suitable for demonstrating that the foam behavior of potassium fatty acid soaps is related to carbon chain length

Table 2 Raw Materials for Saponification, Neutralization, Alkaline Building, and Water-Quality Control

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Alkali source for saponification and neutralization	1310-73-2	S111498	Sodium Hydroxide	Guaranteed reagent, ≥96%	Used for preparing sodium fatty acid soaps; suitable for comparative experiments on the form, solubility, hardness, and cleaning performance of sodium soaps and potassium soaps
Chelating and hard-water control additive	527-07-1	G278703	Sodium D-Gluconate	≥99%	Used for calcium and magnesium ion control and alkaline cleaning systems; suitable for improving soap scum, turbidity, and foam fluctuations of fatty acid soaps in hard water
Chelating and buffering additive	6132-04-3	S116311	Sodium Citrate Dihydrate	AR, ≥99%	Used in water-quality control and buffer systems; suitable for studying the effects of calcium and magnesium ions, pH, and formulation stability on the performance of potassium fatty acid soaps
Alkaline builder	497-19-8	S755926	Sodium Carbonate, Anhydrous	BioReagent, ≥99%	Used in alkaline cleaning and degreasing systems; suitable for studying the effects of alkalinity on oil-soil dispersion, fatty acid salt stability, and hard-surface cleaning performance
Alkaline builder	584-08-7	P485463	Potassium Carbonate	Anhydrous grade, high-purity, reagent grade, ≥99%	Used in potassium-salt alkaline cleaning systems; suitable for pH adjustment, degreasing assistance, and formulation studies of liquid cleaning systems
Alkali source for saponification and neutralization	1310-58-3	P431767	Potassium Hydroxide	Anhydrous grade, ≥99.95% metals basis	A key alkali source for preparing potassium fatty acid soaps; suitable for fatty acid neutralization, saponification endpoint control, free alkali control, and potassium soap formation experiments
Organic amine neutralizer	102-71-6	T478536	Triethanolamine	Reagent grade, ≥98%	Can form triethanolamine fatty acid soaps with fatty acids; used to compare the effects of potassium salts, sodium salts, and organic amine salts on emulsification, skin feel, viscosity, and product form
Strong alkaline builder	10213-79-3	S100563	Sodium Metasilicate Pentahydrate	≥95%	Used in heavy-duty degreasing, hard-surface cleaning, and equipment cleaning systems; suitable for studying alkaline building, corrosion inhibition, degreasing, and the cleaning performance of fatty acid soap blends

Table 3 Comparative and Blending Surfactants

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Sulfate anionic surfactant	151-21-3	S432157	Sodium Dodecyl Sulfate (SDS)	Anhydrous grade, ACS, ≥99%	A typical high-foaming anionic surfactant; used for comparison with potassium fatty acid soaps in terms of head-group structure, foam generation, detergency, and irritation differences
Amino-acid-based anionic surfactant	137-16-6	N476195	Sodium N-Lauroylsarcosinate	UltraBio™, molecular biology grade, ultrapure grade, ≥99% (HPLC)	Used for research on mild cleansing systems; suitable for comparison with potassium fatty acid soaps in weakly acidic cleansing, foam, degreasing power, and skin-cleansing performance
Nonionic glycoside surfactant	68515-73-1	T476404	Decyl Glucoside (APG)	Moligand™, 60% in H₂O	Used in nonionic mild cleansing and blended systems; suitable for comparing differences between glycoside head groups and carboxylate head groups in pH adaptability, foam, and skin feel
Sulfonate anionic surfactant	25155-30-0	S592217	Sodium Dodecylbenzenesulfonate (SDBS)	Anionic active matter, 85%	Used in detergent cleaning and interfacial activity studies; suitable for comparison with potassium fatty acid soaps in hard-water tolerance, foam, degreasing, and differences in anionic head groups
Amphoteric co-surfactant	61789-40-0	C665446	Cocamidopropyl Betaine	Actives content 28%–32% in water	Used in blends with soap bases and anionic surfactants; suitable for improving foam texture, reducing dry or harsh skin feel, and enhancing the sensory performance of rinse-off cleansing systems
Amino-acid-based anionic surfactant	29923-31-7	S339866	Sodium Lauroyl Glutamate	≥95%	Used for research on weakly acidic mild cleansing systems; suitable for comparison with potassium fatty acid soaps in pH adaptability, skin feel, foam, and cleaning power
Nonionic glycoside surfactant	110615-47-9	L196324	Dodecyl Glucoside	≥40%	Used for mild cleansing, thickening in blends, and foam regulation studies; suitable for comparison with potassium fatty acid soaps in terms of the effects of nonionic head groups on foam and skin feel
Polyether sulfate anionic surfactant	9004-82-4	S196294	Sodium Polyoxyethylene Lauryl Ether Sulfate	≥25%	Commonly used in cleaning and foaming systems; suitable for comparison with potassium fatty acid soaps in terms of polyether structure, sulfate ester head group, foam stability, and pH adaptability

Table 4 Low-Foam/Foam-Control, Polyether-Structure, and Functional Auxiliary Materials

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Silicone oil foam-control additive	63148-62-9	S433164	Silicone Oil	Viscosity 5 cSt (25°C)	Used in foam-control and low-foam cleaning systems; suitable for studying defoaming, foam suppression, and surface-spreading behavior in potassium fatty acid soap blend systems
Polyether nonionic surfactant / solubilizing and structure-modifying material	9003-11-6	K434429	Kolliphor® P 407	Oxyethylene content 71.5%–74.9%	A poloxamer-type EO/PO block polyether; can be used in studies of solubilization, wetting, emulsification, micellar behavior, and gel structures; can serve as a comparative material for studying polyether structure, rheology, and interfacial behavior in potassium fatty acid soap blend systems
Polyether foam-control additive	25322-69-4	P103212	Polypropylene Glycol (PPG)	Average molecular weight 4000	Used in low-foam, foam-suppression, and interfacial-regulation systems; suitable for analyzing the effects of polyether structure on foam persistence and wetting performance in potassium fatty acid soap systems
Inorganic structuring and carrier material	7631-86-9	S433694	Silicon Dioxide	Nanoparticles, mesoporous; outer diameter 450–550 nm, pore size 2–4 nm	Used in carrier, rheology, and interfacial-structure studies; suitable for silicone-based foam-control systems, structured cleaning pastes, and loading of functional components

Note: The products listed above are representative Aladdin products related to scientific research and formulation studies. They can be used for research on the structure, preparation, blending, and performance comparison of potassium fatty acid soaps. Specific catalog numbers, packaging, specifications, stock availability, and COA/SDS information should be confirmed on the real-time product pages of the Aladdin website. Searches may be performed by product name, CAS number, or catalog number.

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