Degreasing Agents from a Molecular-Structure Perspective: How AEO, APG, and Related Surfactants Can Replace Nonylphenol Ethoxylates (NPE)

1. The Essence of Degreasing Agents: Regulating the Interfacial Relationships Among Oil, Water, and Surfaces

In household and personal-care cleaning products, “degreasing” does not simply mean dissolving oily soils. Instead, surfactants change the interfacial relationships among oil, water, and the surface being cleaned. As a result, oily soils originally attached to the surface can be wetted, penetrated, detached, emulsified, dispersed, and ultimately carried away by water. Oily soils are difficult to remove with water alone mainly for three reasons:

Why oily soils are difficult to clean	Requirements for a degreasing system
Oil and water are immiscible	The oil–water interfacial tension needs to be reduced
Oily soils readily adhere to substrate surfaces	Wetting, penetration, and detachment capability are required
Detached oily soils may redeposit on the surface	Emulsification, dispersion, and anti-redeposition capability are required

Surfactants can perform degreasing functions because their molecules have an “amphiphilic structure”: one end is oil-affinitive, while the other end is water-affinitive.

Molecular structural part	Functional logic
Hydrophobic end	Approaches the oily soil, enters the oil phase, or adsorbs onto the surface of the oily soil
Hydrophilic end	Interacts with the aqueous phase, allowing the oily soil to be carried by water
Overall amphiphilic structure	Arranges at the oil–water interface and reduces interfacial tension

Therefore, the degreasing process can be understood as a continuous process of interfacial regulation: wetting and spreading → penetration/roll-up → emulsification and dispersion → partial micellar solubilization or mixed-micelle stabilization → rinsing/wiping away. To judge whether a degreasing agent is effective, it is necessary to consider whether its molecular structure can efficiently enter the oil–water interface, whether it matches the target oily soil, and whether it can work synergistically with other components in the formulation.

2. Why Nonylphenol Ethoxylates Were Once Effective

Nonylphenol ethoxylates (NPE) are nonionic surfactants belonging to the alkylphenol ethoxylates (APEO) family. They were once used in cleaners, detergents, textile auxiliaries, industrial cleaning, and other fields mainly because they provided good wetting, emulsification, dispersion, and solubilization performance, while also offering a relatively favorable balance between cost and performance.

2.1 Typical Structure of NPE

NPE can be represented by the following simplified general formula:

C₉H₁₉–C₆H₄–O–(CH₂CH₂O)n–H

Commercial NPE products are usually not single pure compounds, but mixtures containing different nonyl isomers and distributions of different ethylene oxide addition numbers.

Structural unit	Meaning	Function
C₉H₁₉–C₆H₄–	Nonylphenyl hydrophobic end	Approaches oily soils and provides oil affinity and interfacial adsorption capability
–O–(CH₂CH₂O)n–H	Polyoxyethylene hydrophilic chain	Provides water solubility and enables the molecule to disperse in the aqueous phase
n	Number of ethylene oxide units added	Affects hydrophilicity, cloud point, emulsification ability, and application temperature

The longer the ethylene oxide (EO) chain segment, the stronger the hydrophilicity of the molecule generally becomes; when the EO chain segment is shorter, oil affinity becomes relatively more pronounced. By adjusting the EO number, the wetting, emulsification, cloud point, and water-solubility behavior of NPE can be modified.

2.2 The Degreasing Ability of NPE Comes from Structural Division of Function

The cleaning effect of NPE comes from its amphiphilic structure. During degreasing, the hydrophobic end of NPE approaches the oily soil, while the hydrophilic end remains in the aqueous phase. After the molecules arrange at the oil–water interface, they reduce the oil–water interfacial tension, making it easier for oily soils to detach from the surface being cleaned and then become emulsified, dispersed, or solubilized.

Structural feature	Resulting interfacial behavior	Contribution to degreasing
Nonylphenyl hydrophobic end	Interacts with oily soils	Helps the surfactant approach the oily soil
EO hydrophilic chain	Forms hydration interactions with the aqueous phase	Allows dispersed oily soils to remain in the aqueous phase
Nonionic structure	Usually does not readily form insoluble salts with calcium and magnesium ions, giving it relatively good hard-water tolerance	Helps maintain cleaning stability in complex systems
Adjustable EO number	Changes the hydrophilic–lipophilic balance	Adapts to different oily soils and formulation requirements

Mechanism of NPE: one end captures the oily soil, the other enters the aqueous phase, and the EO chain in between regulates water solubility and emulsification capacity. It is this structure that allows NPE to perform key degreasing actions such as wetting, detachment, emulsification, dispersion, and solubilization.

3. Why Degreasing Agents Based on Nonylphenol Ethoxylates (NPE) Need to Be Replaced

The direct reason for replacing NPE/APEO is the environmental and regulatory risk associated with nonylphenol-related structures. In the environment, NPE may undergo processes such as shortening and oxidation of the ethoxylate chain, forming degradation products including short-chain NPE, nonylphenol carboxylates, and nonylphenol. Among these, NP and some short-chain degradation products have attracted attention due to their aquatic toxicity, persistence, and potential endocrine-disrupting effects.

The EU REACH regulation imposes restrictions on the placing on the market and use of nonylphenol (NP) and nonylphenol ethoxylates (NPE) in specific applications and at specific concentration thresholds. For example, when NP/NPE are present as substances or in mixtures at concentrations equal to or greater than 0.1% w/w in applications such as industrial and institutional cleaning, domestic cleaning, textile and leather processing, metalworking, cosmetics, and personal-care products, they are subject to restrictions. NPE in textile articles that can be washed in water during their normal life cycle is also restricted when the concentration is equal to or greater than 0.01% w/w. China’s List of Key New Pollutants for Control (2023 Edition) has listed nonylphenol as a key controlled substance and clearly prohibits the use of nonylphenol as an auxiliary in the production of pesticide products, the use of nonylphenol to produce nonylphenol ethoxylates, and the use of nonylphenol as a cosmetic ingredient.

Therefore, the essence of replacing nonylphenol-related systems is to use new surfactant structures to accomplish similar interfacial tasks:

① Retain effective functions such as wetting, penetration, emulsification, dispersion, and solubilization;

② Avoid continued reliance on alkylphenol structures;

③ Reduce environmental, regulatory, and restriction-related risks;

④ Build APEO-free systems that are more suitable for the development of household and personal-care cleaning products.

4. Typical Alternative Structures: Why Different Products Can Work

A nonylphenol replacement system is usually not built from a single product that performs all functions. Instead, it is generally constructed from multiple types of surfactants and auxiliaries working together.

Among them, alcohol ethoxylates (AEO) often serve as important nonionic degreasing, emulsifying, and solubilizing components; alkyl polyglucosides (APG) and glucamides are used to improve mildness and emulsion stability; linear alkylbenzene sulfonates (LAS), alcohol ether sulfates (AES), and alpha-olefin sulfonates (AOS) are used to enhance basic cleaning, foam, and soil dispersion; cocamidopropyl betaine (CAPB) and amine oxides are used to improve foam stability, mildness, and system compatibility.

4.1 AEO: Replacing the Alkylphenol Hydrophobic End with a Fatty Alcohol Hydrophobic Chain

AEO is a common direction for NPE replacement in household and personal-care degreasing systems. Its typical structure is:

R–O–(CH₂CH₂O)n–H

Here, R represents the fatty alcohol alkyl chain, and –(CH₂CH₂O)n–H represents the EO hydrophilic chain.

The similarity between AEO and NPE lies in the fact that both have a hydrophobic end and an EO hydrophilic chain, both are nonionic surfactants, and both can arrange at the oil–water interface and reduce interfacial tension. The key difference is that the hydrophobic end of NPE is a nonylphenyl structure, whereas the hydrophobic end of AEO is a fatty alcohol alkyl chain.

Comparison item	NPE	AEO
Simplified structure	C₉H₁₉–C₆H₄–O–(CH₂CH₂O)n–H	R–O–(CH₂CH₂O)n–H
Hydrophobic end	Nonylphenyl	Fatty alcohol alkyl chain
Hydrophilic end	EO chain	EO chain
Surfactant type	Nonionic	Nonionic
Replacement logic	Provides wetting, emulsification, and solubilization capability	Retains the EO-based nonionic structure while replacing the alkylphenol structure with a fatty alcohol chain

AEO can undertake the main degreasing function because its hydrophobic chain can enter the oil phase, while its EO chain can form hydration interactions with the aqueous phase. When the molecule is located at the oil–water interface, it can reduce oil–water interfacial tension, allowing oily soils to detach more easily from the surface and become emulsified. The performance of AEO is not fixed; it is closely related to the hydrophobic-chain length and the EO number.

Structural parameter	Effect on performance
Shorter hydrophobic chain	Better water solubility and faster wetting, but may provide insufficient oil affinity for heavy oily soils
Longer hydrophobic chain	Stronger oil affinity and more favorable interaction with oily soils, but water solubility and low-temperature stability need attention
Lower EO number	Stronger oil affinity and suitable for emulsifying certain oily soils, but water solubility may be weaker
Higher EO number	Stronger hydrophilicity, better water solubility and rinsability, but affinity for certain oily soils may decrease

4.2 APG: Using a Sugar-Based Hydrophilic Head to Improve Mildness and Emulsion Stability

The typical structure of APG can be simplified as:

R–O–(Glu)m

Here, R represents the alkyl hydrophobic chain, Glu represents the glucosyl unit, and m represents the average degree of polymerization. Actual APG products are usually mixtures with different alkyl-chain lengths and different degrees of glycoside polymerization.

The common feature of APG and AEO is that both have an amphiphilic structure consisting of a “hydrophobic end + hydrophilic end.” The difference is that the hydrophilic end of AEO is an EO chain, whereas the hydrophilic end of APG is a sugar-based structure.

Comparison item	AEO	APG
Hydrophobic end	Fatty alcohol alkyl chain	Alkyl chain
Hydrophilic end	EO chain	Sugar-based group
Surfactant type	Nonionic	Nonionic
Main function	Degreasing, emulsification, solubilization	Mildness, emulsion stability, and synergistic cleaning

The sugar-based hydrophilic head of APG has strong hydrophilicity and usually helps improve system mildness and emulsion stability. Actual mildness is still related to alkyl-chain distribution, residual fatty alcohol, pH, dosage, and the overall formulation system. Its hydrophobic alkyl chain can still participate in interactions at the oily-soil interface, so APG can help emulsify and disperse oily soils.

Structural parameter	Effect on performance
Shorter alkyl chain	Better water solubility and foam performance
Longer alkyl chain	Stronger oil affinity and potentially improved ability to emulsify oily soils, but solubility needs attention
Variation in glycoside polymerization degree	Affects hydrophilicity, viscosity, foam, and system compatibility

The value of APG lies in its role as a synergistic component in compound systems, improving emulsion stability, mildness, and overall formulation performance.

4.3 Glucamides: Enhancing Mild Cleaning and Emulsification Synergy Through a Polyhydroxy Structure

Glucamide surfactants are usually composed of a fatty chain, an amide linkage, and a polyhydroxy sugar-derived hydrophilic part. Their simplified structure can be represented as:

R–CO–N(R')–Glu

Here, R represents the fatty chain, and Glu represents an open-chain polyhydroxy hydrophilic structure derived from glucose.

The structural characteristics of glucamides are as follows: the fatty chain provides oil affinity, the polyhydroxy structure provides hydrophilicity, and the amide structure helps improve intermolecular interactions and system compatibility.

Structural feature	Effect on performance
Fatty chain	Participates in interactions at the oily-soil interface
Polyhydroxy hydrophilic structure	Provides hydrophilicity and mildness
Amide linkage	Improves emulsion stability and formulation compatibility

In nonylphenol replacement systems, glucamides usually do not serve as the sole primary degreasing agent. Instead, they are used to improve mild cleaning, emulsion stability, and compound-system performance. They are suitable for combination with AEO, APG, AES, and other surfactants in household and personal-care products that require both mildness and cleaning efficiency.

4.4 LAS: Enhancing Detergency, Foam, and Dispersion Through an Anionic Head Group

The typical structure of LAS can be represented as:

R–C₆H₄–SO₃⁻M⁺

Here, R represents a linear alkyl group, –C₆H₄– is the benzene-ring structure, –SO₃⁻M⁺ is the sulfonate anionic hydrophilic head group, and M⁺ is commonly Na⁺.

LAS is an anionic surfactant. Its hydrophobic end can interact with oily soils or hydrophobic dirt, while the sulfonate head group carries a negative charge in water and has strong hydration ability. The main functional logic of LAS can be summarized in two points:

① The charged head group promotes soil dispersion:

After LAS adsorbs onto the surface of dirt particles or oil droplets, the surface becomes negatively charged. Electrostatic repulsion between particles makes them less likely to reaggregate, helping soils remain dispersed and suspended.

② The anionic structure enhances foam and basic cleaning:

LAS has strong foaming and detergency capabilities and can enhance the basic cleaning performance of dishwashing liquids, detergents, and similar products.

The advantages of LAS lie in foam generation, basic detergency, and soil dispersion. In actual formulations, LAS is often compounded with AEO, APG, CAPB, or amine oxides to balance degreasing, foam, mildness, and cost.

4.5 AES: Combining Foam, Cleaning, and Good Formulation Compatibility

The typical structure of AES can be represented as:

R–O–(CH₂CH₂O)n–O–SO₃⁻M⁺

Here, R represents the fatty alcohol alkyl chain, –(CH₂CH₂O)n– is the EO chain, –O–SO₃⁻M⁺ is the sulfate ester hydrophilic head group, and M⁺ is commonly Na⁺.

AES is an anionic surfactant. Compared with fatty alcohol sulfates, AES introduces an EO chain between the hydrophobic alkyl chain and the sulfate ester head group. This structure brings three effects:

Structural unit	Effect on performance
R–	Provides hydrophobicity and participates in interactions with oily soils and hydrophobic dirt
–(CH₂CH₂O)n–	Improves water solubility and formulation compatibility, and enhances mildness
–O–SO₃⁻M⁺	Provides an anionic hydrophilic head group and enhances foaming, detergency, and dispersion

AES is widely used in dishwashing liquids, hand washes, and cleaning agents because it can provide both foam and basic detergency, while the EO chain improves water solubility and formulation performance. In nonylphenol replacement systems, AES does not primarily take over the nonionic emulsification and solubilization functions of NPE. Instead, it mainly undertakes foam generation, basic detergency, and soil-dispersion functions. When compounded with AEO, AEO focuses more on oily-soil emulsification and solubilization, while AES focuses more on foaming and dispersion. Together, they form a more complete cleaning system.

4.6 AOS: Enhancing Foam and Soil Dispersion

AOS is usually a mixture of alkene sulfonates and hydroxyalkyl sulfonates. It can be simplified as a surfactant with a long-chain hydrophobic group and a sulfonate anionic head group.

Its structural features can be summarized as:

Long-chain hydrophobic group + –SO₃⁻M⁺ sulfonate hydrophilic head group

The functional logic of AOS is similar to that of LAS: the long-chain hydrophobic group participates in interactions with oily soils and hydrophobic dirt, while the sulfonate anionic head group provides water solubility, foaming ability, and dispersion capability. AOS is commonly used in cleaning systems that require foam, cleaning power, and water solubility. In degreasing formulations, AOS more often undertakes basic cleaning, foaming, and dispersion functions rather than serving alone as the primary emulsifying and solubilizing component.

4.7 CAPB: Improving Foam Stability, Mildness, and System Compatibility Through an Amphoteric Structure

The typical structure of CAPB can be represented as:

R–CONH–(CH₂)₃–N⁺(CH₃)₂–CH₂COO⁻

Here, R–CONH– is the fatty amide hydrophobic part. The molecule contains both a quaternary ammonium cationic structure and a carboxylate anionic structure, giving it amphoteric surfactant characteristics.

The function of CAPB is not simply to increase degreasing strength, but to improve the overall performance of the system.

Structural feature	Resulting function
Long-chain fatty amide hydrophobic end	Participates in interactions with oily soils and hydrophobic interfaces
Amphoteric/zwitterionic hydrophilic head	Improves mildness and formulation compatibility
Compounding with anionic surfactants	Improves foam stability, viscosity, and sensory feel

In systems containing anionic surfactants such as AES and LAS, CAPB can improve foam stability through compounding effects and reduce the irritation associated with a single anionic surfactant. For dishwashing liquids, hand-cleaning products, and mild cleaning products, the value of CAPB lies mainly in foam stabilization, improved mildness, and auxiliary thickening.

4.8 Amine Oxides: Enhancing Foam, Emulsification, and Oily-Soil Dispersion

The typical structure of an amine oxide can be represented as:

R–N⁺(CH₃)₂–O⁻

Here, R is a long-chain alkyl group, and –N⁺(CH₃)₂–O⁻ is a strongly polar amine oxide head group.

Amine oxides have pronounced polarity, and their behavior can vary under different pH conditions. They are commonly used in dishwashing liquids and cleaning agents to enhance foam, foam stability, thickening, and oily-soil dispersion.

The functional logic of amine oxides is as follows:

① The long-chain alkyl group provides oil affinity and can participate in interactions at the oily-soil interface;

② The polar head group provides compatibility with the aqueous phase;

③ When compounded with anionic surfactants, it can improve foam stability and system viscosity;

④ It provides auxiliary emulsification and dispersion of oily soils.

Amine oxides are not direct one-to-one replacements for nonylphenol-based materials. Instead, they are performance-modifying components in compound degreasing systems.

5. Functional Division of Different Structures from the Perspective of the Degreasing Process

Degreasing is not an action completed by a single molecule alone. Rather, different structures work together at different stages.

Degreasing stage	Key structure	Typical products	Functional logic
Wetting and spreading	Hydrophilic head group reduces the surface tension of the aqueous phase	AEO, APG, AES	Enables the cleaning solution to quickly contact the oily-soil surface
Penetration and detachment	Hydrophobic chain enters the oily-soil phase	AEO, isomeric alcohol ethoxylates, amine oxides	Weakens the adhesion between oily soils and the substrate
Emulsification of oily soils	Hydrophobic ends surround oil droplets, while hydrophilic ends face the aqueous phase	AEO, APG, glucamides	Converts larger oily soils into relatively stable small oil droplets
Soil dispersion	Charged head groups generate electrostatic repulsion	LAS, AES, AOS	Reduces reaggregation and redeposition of soils
Micellar solubilization	Surfactants form micelles or mixed micelles	AEO, AES, APG compound systems	Stabilizes part of the oil-soluble dirt in the aqueous phase
Foam stabilization and improved usability	Amphoteric or strongly polar head groups participate in compounding	CAPB, amine oxides	Improves foam, mildness, and system stability

From this process, it can be seen that AEO is suitable as a primary degreasing structure because it has a good hydrophilic–lipophilic balance in oil–water interfacial action. APG and glucamides are suitable for improving emulsion stability and mildness. LAS, AES, and AOS are suitable for enhancing foam and soil dispersion. CAPB and amine oxides are suitable for improving foam stability, mildness, and system compatibility.

The key to replacing nonylphenol-based systems is precisely to recombine these structures according to their functions, rather than simply replacing one raw material with another.

6. How to Judge Whether a Replacement System Is Reasonable

6.1 Check Whether the Hydrophobic Chain Matches the Type of Oily Soil

Different types of oily soils have different requirements for hydrophobic chains. Animal and vegetable oils, mineral oils, sebum, and aged heavy oily soils differ significantly in composition. If the hydrophobic chain is too short, it may not interact sufficiently with heavy oily soils; if it is too long, water solubility, low-temperature stability, and rinsability may become concerns. When selecting AEO, APG, amine oxides, and related products, attention should be paid to hydrophobic-chain length and structure.

Type of oily soil	Key considerations
Animal and vegetable oils	Emulsification ability, foam, and rinsability
Mineral oils	Penetration, solubilization, and cosolvent synergy
Sebum soils	Mildness, emulsification, and anti-redeposition
Aged heavy oily soils	Synergy among nonionic surfactants, alkaline agents, and cosolvents
Mixed soils	Multi-structure compounding and dispersion stability

6.2 Check Whether the Hydrophilic Head Group Meets Water-Solubility and Rinsability Requirements

The hydrophilic head group determines the dispersibility of a surfactant in water and also affects foam, irritation, hard-water tolerance, and rinsability.

Type of hydrophilic head group	Typical products	Main effects
EO chain	AEO, AES	Regulates water solubility, cloud point, emulsification, and mildness
Sugar-based group	APG, glucamides	Improves mildness and emulsion stability
Sulfonate head group	LAS, AOS	Provides foaming, dispersion, and basic cleaning power
Sulfate ester head group	AES	Provides foam, detergency, and water solubility
Betaine head group	CAPB	Improves foam stability, mildness, and system compatibility
Amine oxide head group	Amine oxides	Enhances foam, viscosity, and auxiliary emulsification

6.3 Check Whether the HLB Is Suitable for the Target System

The hydrophilic–lipophilic balance (HLB) value is used to indicate the relative strength of a surfactant’s hydrophilicity and lipophilicity. If the HLB is too low, the surfactant may have insufficient water solubility; if the HLB is too high, its affinity for the oil phase may be insufficient. For degreasing systems, the HLB should match the type of oily soil, product form, use temperature, pH, and electrolyte content.

HLB is suitable as an initial screening indicator for nonionic emulsifiers. For anionic, amphoteric, and nonionic compound systems, it should also be evaluated together with CMC, cloud point, interfacial tension, foam, detergency, pH, electrolytes, and storage stability.

6.4 Check Whether the EO Number and Cloud Point Are Suitable for the Formulation

For products containing EO chains, such as AEO and AES, the EO number affects water solubility, cloud point, emulsification ability, foam performance, and low-temperature stability. When the EO number is lower, the product is relatively more lipophilic and may be more favorable for acting on certain oily soils, but water solubility and clarity need attention. When the EO number is higher, water solubility increases, but affinity for certain oily soils may decrease.

Cloud point is also important. Under certain temperature conditions, nonionic surfactants may become cloudy or undergo phase separation, affecting the appearance, storage stability, and actual cleaning performance of the formulation. Therefore, when replacing NPE, degreasing power, low-temperature stability, heat stability, clarity, and storage performance all need to be considered.

6.5 Check Whether Compounding Creates Synergy

The purpose of compounding is to allow different structures to undertake different tasks. A reasonable nonylphenol replacement system should simultaneously meet requirements for degreasing, foam, rinsability, stability, mildness, and cost, rather than pursuing only a single performance indicator.

Formulation task	Suitable products
Primary degreasing, emulsification, solubilization	AEO, isomeric alcohol ethoxylates
Mildness and emulsion stability	APG, glucamides
Foam and basic cleaning	AES, LAS, AOS
Foam stabilization, thickening, and reduced irritation	CAPB, amine oxides
Softening and penetration of heavy oily soils	Alkaline agents, cosolvents
Hard-water resistance and stable cleaning performance	Chelating agents, nonionic surfactants

7. Formulation Concepts for Typical Household and Personal-Care Degreasing Products

7.1 Dishwashing Liquid

Dishwashing liquid deals with tableware grease, animal and vegetable oils, and some mixed soils. It not only needs to remove grease, but also requires foam, rinsability, and mildness for hand contact.

A common formulation concept is:

AEO/APG + AES/LAS/AOS + CAPB/amine oxide

In this system, AEO undertakes primary degreasing and emulsification; APG improves mildness and emulsion stability; AES, LAS, or AOS provides foam and basic cleaning; and CAPB or amine oxide improves foam stability, viscosity, and user experience.

7.2 Kitchen Heavy-Duty Degreasing Cleaners

Kitchen heavy oily soils usually contain aged grease, oxidized oils, dust, and carbonized residues. They have strong adhesion, and ordinary foam-type cleaning systems may not be sufficient.

A common formulation concept is:

AEO/isomeric alcohol ethoxylate + cosolvent + alkaline agent + chelating agent

In this system, AEO or isomeric alcohol ethoxylate is responsible for wetting and emulsification; the cosolvent helps penetrate and soften oily soils; the alkaline agent promotes saponification of fatty-acid-type soils; and the chelating agent reduces the negative impact of hard-water ions on cleaning performance. Kitchen heavy-duty degreasing cleaners do not necessarily require high foam. Instead, they require rapid wetting, penetration, emulsification, and easy wiping.

7.3 Hard-Surface Cleaners

Hard-surface cleaners emphasize low residue, easy wiping, non-tacky feel, and a clean, polished surface. Excessive foam may instead increase the burden of wiping.

A common formulation concept is:

Low-foam AEO/low-foam nonionic surfactant + cosolvent + chelating agent

These systems should prioritize wetting, low residue, clarity and stability, and easy wiping, rather than simply pursuing high foam.

7.4 Mild Cleaning Products

If a product emphasizes mildness, the proportion of sugar-based surfactants such as APG and glucamides can be increased, and they can be compounded with AEO, AES, CAPB, and other surfactants.

A common formulation concept is:

APG/glucamide + AEO + mild anionic surfactant + CAPB

The focus of such products is not simply to pursue the strongest removal of heavy oily soils, but to achieve a balance among cleaning power, mildness, foam, rinsability, and formulation stability.

8. High Cost-Effectiveness Comes from Structural Matching, Not the Lowest Unit Price

In household and personal-care degreasing formulations, high cost-effectiveness does not mean using the cheapest raw material. True cost-effectiveness depends on the cost per unit of cleaning performance. The following factors should be considered comprehensively:

① Active matter content;

② Effective dosage;

③ Removal efficiency for the target oily soil;

④ Low- and high-temperature storage stability;

⑤ Foam, rinsability, and residue feel;

⑥ Compatibility with pH, electrolytes, fragrance, and preservative systems;

⑦ Regulatory and restriction risks;

⑧ Supply stability and batch-to-batch consistency.

Replacing nonylphenol ethoxylates (NPE) is not a simple one-to-one substitution of one raw material with another. Instead, it involves using an alkylphenol-free surfactant system to reconstruct interfacial functions such as wetting, penetration, emulsification, dispersion, solubilization, and rinsing.

Fatty alcohol ethoxylates such as AEO can serve as important nonionic degreasing and emulsifying components. APG and glucamides can improve mildness, emulsion stability, and formulation compatibility. Anionic surfactants such as AES, LAS, and AOS can enhance foam, basic detergency, and soil dispersion. CAPB and amine oxides help improve foam stability, viscosity adjustment, reduced irritation, and system stability. In practice, a replacement system should be comprehensively selected based on oily-soil type, HLB/cloud point, pH, electrolytes, foam, storage stability, regulatory restrictions, and the cost per unit of cleaning performance.

9. Representative Chemicals Related to Nonylphenol Replacement in Degreasing Agents from a Molecular-Structure Perspective: AEO, APG, and Related Products

Table 1. Nonylphenol-Related Reference Materials and Background Substances for Replacement Studies

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Nonylphenol-related reference material	9016-45-9	N1372295	Nonylphenol Ethoxylate (Tergitol NP-40)	Mixture of isomers, white flakes	Used for reference studies on the structure, nonionic surface activity, emulsification performance, and replacement systems of nonylphenol ethoxylates
Nonylphenol-related reference material	25154-52-3	N770913	Nonylphenol (mixture of isomers)	≥99.5%	Used for research on nonylphenol-related environmental risks, regulatory replacement background, and analytical methods

Table 2. Core Degreasing and Alternative Surfactants

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Primary nonionic degreasing surfactant	68131-39-5	A304365	Alcohol Ethoxylate	Mw 400–500	Contains a fatty alcohol hydrophobic chain and a polyoxyethylene hydrophilic chain; used in studies on wetting, emulsification, solubilization, and primary degreasing in nonylphenol replacement systems
Nonionic emulsifying and solubilizing surfactant	68439-49-6	C196296	Ceteareth-13	100%	Contains a long-chain fatty alcohol structure and a polyoxyethylene chain; used in studies on oily-soil emulsification, formulation solubilization, interfacial behavior, and nonionic surface activity
Sugar-based nonionic surfactant	58846-77-8	D112862	Decyl Glucopyranoside	Biochemical reagent	Contains an alkyl hydrophobic chain and a sugar-based hydrophilic head; used in studies on sugar-based surfactant structure, mild cleaning, emulsion stability, and formulation synergy
Sugar-based nonionic surfactant	68515-73-1	T476404	Decyl Glucoside (APG)	Moligand™, 60% in H₂O	Contains an alkyl chain and a sugar-based hydrophilic structure; used in APEO-free cleaning systems, mild cleaning, and emulsification-synergy studies
Sugar-based nonionic surfactant	110615-47-9	L196324	Lauryl Glucoside	≥40%	Contains a relatively long alkyl chain and a sugar-based hydrophilic head; used in studies on oily-soil emulsification, foam regulation, mild cleaning, and sugar-based surfactant compounding

Table 3. Representative Surfactants for Compounding Synergy and Mechanistic Studies

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Anionic surfactant	151-21-3	S432157	Sodium Dodecyl Sulfate (SDS)	Anhydrous, ACS, ≥99%	Contains a long-chain alkyl group and a sulfate ester hydrophilic head; used in studies on foaming, detergency, micellar behavior, and anionic surfactant reference systems
Anionic surfactant	25155-30-0	S592217	Sodium Dodecylbenzenesulfonate (SDBS)	Anionic active matter, 85%	Contains an alkylbenzene hydrophobic end and a sulfonate hydrophilic head; used in studies on basic detergency, foam, soil dispersion, and surface activity
Anionic surfactant	68439-57-6	S304377	Sodium Alpha-Olefin Sulfonate	≥92%	Contains a long-chain hydrophobic group and a sulfonate hydrophilic head; used in studies on foaming, dispersion, detergency, and anionic surfactant compounding in cleaning systems
Anionic surfactant	9004-82-4	S196294	Sodium Polyoxyethylene Lauryl Ether Sulfate	≥25%	Contains an alkyl chain, a polyoxyethylene chain, and a sulfate ester head group; used in studies on foam cleaning, oily-soil dispersion, and synergy with nonionic surfactants
Amphoteric surfactant	61789-40-0	C665446	Cocamidopropyl Betaine	Active content 28%–32% in water	Contains a fatty amide hydrophobic chain and a betaine amphoteric head group; used in studies on foam stabilization, mildness improvement, system thickening, and compounding with anionic surfactants
Amine oxide surfactant	1643-20-5	N755731	N,N-Dimethyldodecylamine N-Oxide (DDAO)	BioReagent, ≥99%	Contains a dodecyl hydrophobic chain and an amine oxide polar head group; used in studies on foam stabilization, auxiliary emulsification, micelles, and degreasing compound systems

Table 4. Representative Auxiliaries, Chelating Agents, Alkaline Agents, and Cosolvents for Cleaning Systems

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Chelating agent	51981-21-6	T303874	Tetrasodium N,N-Bis(carboxymethyl)-L-glutamate	Effective content ≥47%	Used in studies on calcium and magnesium ion chelation, cleaning stability under hard-water conditions, phosphate-free cleaning systems, and degreasing formulation auxiliaries
Chelating dispersant	527-07-1	G104995	Sodium D-Gluconate	Pharmaceutical grade, PharmPure™	Used in studies on metal-ion chelation, dispersion in alkaline systems, hard-water tolerance, and auxiliary cleaning of heavy oily soils
Chelating buffer	68-04-2	T774745	Trisodium Citrate	Anhydrous, USP	Used in studies on buffering, complexation of calcium and magnesium ions, adjustment of cleaning-system stability, and mild degreasing formulations
Alkaline agent	1310-58-3	P431767	Potassium Hydroxide	Anhydrous, ≥99.95% metals basis	Used in studies on alkaline cleaning systems, saponification of fatty-acid-type oily soils, acid–base adjustment in liquid cleaners, and heavy oily-soil treatment
pH adjuster	102-71-6	T478536	Triethanolamine	Reagent grade, ≥98%	Used in studies on acid–base adjustment, surfactant-system compatibility, auxiliary solubilization, and liquid cleaning formulations
Alkaline builder	6834-92-0	S102095	Sodium Metasilicate, Anhydrous	SiO₂, 44%–47%	Used in studies on strongly alkaline degreasing, hard-surface cleaning, oily-soil softening, builder systems, and metal-surface cleaning
Alkaline agent	497-19-8	S141342	Sodium Carbonate, Anhydrous	≥99.5%	Used in studies on providing alkalinity, promoting oily-soil emulsification, improving cleaning power under hard-water conditions, and builder systems
Alkaline agent	1310-73-2	S580606	Sodium Hydroxide	≥98%, granules	Used in studies on strongly alkaline degreasing, aged oily-soil treatment, saponification of fatty-acid-type soils, and acid–base adjustment in cleaning systems
Cosolvent	5131-66-8	B151801	Propylene Glycol Butyl Ether	≥99% (GC)	Used in studies on oily-soil penetration, dissolution of hydrophobic dirt, hard-surface cleaning, and degreasing spray formulations
Cosolvent	34590-94-8	D108833	Dipropylene Glycol Methyl Ether	≥98%	Used in studies on surfactant cosolvency, oily-soil penetration, low-temperature stability, and hard-surface cleaning systems
Naturally derived cosolvent	5989-27-5	L106923	(R)-(+)-Limonene	≥95%, contains 0.03% alpha-tocopherol as stabilizer	Used in studies on greasy-soil dissolution, fragrance-type cleaning systems, terpene cosolvents, and degreasing formulations
Chelating agent	164462-16-2	T161558	Trisodium N-(1-Carboxyethyl)iminodiacetate	≥95% (T)	Used in studies on calcium and magnesium ion chelation, hard-water cleaning stability, phosphate-free builder systems, and degreasing formulations
Alkaline builder	10213-79-3	S100563	Sodium Metasilicate Pentahydrate	≥95%	Used in studies on alkaline degreasing, hard-surface cleaning, oily-soil softening, builder systems, and heavy-duty degreasing systems
Cosolvent	64-17-5	E111963	Ethanol	Pharmaceutical grade, PharmPure™, ≥99.5%	Used in studies on cosolvency in cleaning systems, quick drying, surface cleaning, fragrance dissolution, and volatile solvent systems
Cosolvent	67-63-0	I112011	Isopropanol (IPA)	AR, ≥99.7%	Used in studies on hard-surface cleaning, quick drying, auxiliary soil removal, surface degreasing, and solvent-based cleaning systems

Note: The products listed above are representative Aladdin products for scientific research and formulation studies. For more product specifications, grades, and COA information, please search by “product name/CAS/catalog number” on the Aladdin official website. These products are suitable for laboratory studies on surface activity, micelles, detergency, or replacement-system comparisons. Actual large-scale household and personal-care cleaning formulations still need to be re-screened based on product regulations, industrial-grade supply, active matter content, impurity control, irritation potential, cost, and application testing.

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