Cashew Nut Shell Liquid (CNSL): From Cashew Processing By-Product to Reactive Bio-Based Raw Material for Coating Resins

1 Material Positioning of Cashew Nut Shell Liquid (CNSL)

1.1 CNSL is a naturally derived reactive phenolic raw material

Cashew Nut Shell Liquid, abbreviated as CNSL, is a dark, viscous liquid extracted from cashew nut shells. It is derived from a non-edible by-product generated during cashew processing. Rich in phenolic compounds, it can be used as a raw material for coating resins, adhesives, friction materials, composites, and functional polymers.

CNSL differs from rosin, shellac, dammar resin, and natural lacquer in its role in coatings. The core value of CNSL lies in its ability to provide reactive phenolic hydroxyl groups, long-chain alkyl groups, and unsaturated bonds. As a naturally derived phenolic raw material, it can be incorporated into epoxy resins, polyurethane resins, phenolic resins, alkyd resins, and other systems to adjust resin hydrophobicity, flexibility, adhesion, and bio-based content.

Comparison Item	CNSL	Traditional Natural Varnish Resins
Source	Cashew nut shell processing by-product	Plant exudates, animal secretions, or natural resin blocks
Main composition	Phenolic compounds such as cardanol, cardol, anacardic acid, and 2-methylcardol	Resin acids, triterpenes, natural polyesters, etc.
Main role	Reactive resin raw material, modifier, curing-agent raw material	Film formation, sealing, gloss enhancement, decoration
Coating value	Improves hydrophobicity, flexibility, adhesion, and bio-based content	Provides transparency, gloss, sealing, or a traditional appearance
Method of use	Mostly requires chemical conversion before use	Can be used directly or after simple dissolution
Key limitations	Color, odor, purity, batch stability, and reaction control	Yellowing, brittleness, insufficient resistance, or aging

1.2 Sources and types of CNSL

CNSL is present in the honeycomb-like structure of cashew nut shells. Its composition varies significantly depending on the extraction and processing method. It is generally classified into natural CNSL, technical CNSL, and distilled CNSL.

Type	Production Method	Compositional Characteristics	Application Characteristics
Natural CNSL	Cold pressing or solvent extraction	High anacardic acid content; contains cardol, 2-methylcardol, and a small amount of cardanol	Suitable for further separation and chemical conversion
Technical CNSL	Heat treatment, roasting, or hot extraction	Anacardic acid is decarboxylated to form cardanol, increasing the cardanol content	More commonly used in industrial applications
Distilled CNSL	Distillation and refining of technical CNSL	Higher cardanol content and fewer impurities	Suitable for preparing high-performance resin raw materials

Anacardic acid in natural CNSL readily decarboxylates into cardanol during heating. Therefore, technical CNSL and distilled CNSL often contain cardanol as the main component.

1.3 Main value of CNSL in coating resins

The value of CNSL in coatings comes from its unique structure. It contains phenolic hydroxyl groups, long-chain alkyl groups, and unsaturated bonds, allowing it both to participate in reactions and to improve resin hydrophobicity and flexibility.

Coating Value	Specific Contribution
Natural origin	Derived from cashew processing by-products, helping increase the proportion of renewable content
Phenolic hydroxyl reactivity	Can participate in the design of phenolic, epoxy, polyurethane, and other systems
Long-chain alkyl groups	Provide hydrophobicity, flexibility, and an internal plasticizing effect
Unsaturated bonds	Can participate in oxidation, addition, epoxidation, or crosslinking reactions
Aromatic ring structure	Helps improve resin cohesion and heat resistance
Chemical convertibility	Can be used to prepare polyols, epoxy diluents, curing agents, phenolic resins, and alkyd resin modifiers

2 Core Structure–Property Relationships of CNSL

2.1 Main components: cardanol, cardol, anacardic acid, and 2-methylcardol

CNSL is a mixture of various substituted phenolic compounds, mainly including cardanol, cardol, anacardic acid, 2-methylcardol, and small amounts of other components. Cardanol is one of the important industrial derivatives of CNSL and is usually a mixture of monophenolic homologues containing C15 saturated side chains or side chains with different degrees of unsaturation.

Component	Structural Characteristics	Significance for Coating Resins
Cardanol	Monophenolic structure, usually containing a C15 saturated side chain or side chains with different degrees of unsaturation	Moderate reactivity; suitable for preparing epoxy-, phenolic-, and polyurethane-related raw materials
Cardol	Diphenolic structure with a C15 unsaturated long chain	Higher reactivity; can improve crosslinking or curing capability
Anacardic acid	Contains both a carboxyl group and a phenolic hydroxyl group, with a C15 unsaturated long chain	High content in natural CNSL; can decarboxylate into cardanol upon heating
2-Methylcardol	Substituted diphenolic structure with a long-chain alkyl group	Affects reactivity, color, and compositional stability
Polymers and heavy components	Formed during heat treatment or storage	Affect color, viscosity, odor, and reaction stability

2.2 Phenolic hydroxyl groups and reactivity

The phenolic hydroxyl groups in CNSL molecules are key structural units that allow CNSL to participate in resin synthesis. Phenolic hydroxyl groups can participate in phenolic condensation, epoxy ring-opening, and amination reactions. They can also serve as starting points for preparing curing agents, reactive diluents, and polyols.

Reaction Direction	Significance for Coating Resins
Phenolic condensation	Can be used to prepare CNSL-modified phenolic resins
Epoxidation reaction	Can be used to prepare cardanol-based epoxy diluents or epoxy resins
Amination or Mannich reaction	Can be used to prepare epoxy curing agents or curing-accelerating structures
Hydroxylation or polyol formation	Can be used to prepare bio-based polyols for polyurethane
Salt formation or emulsification modification	Helps with the design of waterborne systems

2.3 Long-chain alkyl groups, hydrophobicity, and flexibility

CNSL derivatives usually contain C15 long-chain alkyl groups. This long-chain structure is an important reason why CNSL differs from ordinary phenol. It can reduce resin polarity, improve hydrophobicity, and positively influence coating-film flexibility and impact resistance.

Structural Role	Effect on Coating-Film Performance
Improved hydrophobicity	Reduces water sensitivity and improves water resistance and moisture resistance
Improved flexibility	Reduces excessive resin rigidity and lowers the risk of brittleness and cracking
Internal plasticizing effect	Improves coating-film toughness and application flow
Improved substrate wetting	Helps wet metals, wood, and some low-polarity substrates
Reduced brittleness from excessive crosslinking	Helps adjust toughness in epoxy and phenolic systems

2.4 Unsaturated bonds and further modification

The side chains of CNSL contain different degrees of unsaturation. Naturally derived cardanol is usually a mixture of components with different degrees of unsaturation, including saturated, monoene, diene, and triene structures. Unsaturated bonds bring two types of effects:

Function	Positive Effect	Risk
Oxidative crosslinking	Can improve film formation and curing capability	May cause color darkening or storage deterioration
Epoxidation	Can be used to prepare epoxidized cardanol derivatives	Requires strict reaction control
Addition reaction	Can introduce new functional groups	Product composition may become complex
Polymerization	Can increase molecular weight and coating-film cohesion	May lead to viscosity increase or gelation
Retention of hydrophobic side chains	Improves flexibility and water resistance	Excessive amounts may reduce hardness and heat resistance

3 Main Modification Routes of CNSL

3.1 CNSL-modified phenolic resins

CNSL contains phenolic structures and can partially replace phenol in the synthesis of phenolic resins. Because CNSL molecules contain long-chain alkyl groups, CNSL-modified phenolic resins usually show better flexibility, hydrophobicity, and impact resistance.

Modification Effect	Significance for Coating Applications
Improved hydrophobicity	Improves water resistance, moisture resistance, and corrosion-protection-related performance
Improved flexibility	Reduces the brittleness of conventional phenolic resins
Improved adhesion	Helps bonding to metals and porous substrates
Improved chemical resistance	Aromatic phenolic structures and crosslinked structures provide a basis for resistance
Use of renewable raw materials	Reduces partial dependence on petrochemical phenolic raw materials

3.2 CNSL-modified epoxy resins

CNSL derivatives can be used in epoxy systems. Common approaches include preparing cardanol-based epoxy diluents, epoxy resin modifiers, epoxy curing agents, or curing accelerators. The long-chain structure of CNSL can improve the flexibility and impact resistance of conventional epoxy systems.

Application Form	Main Function
Cardanol-based epoxy diluent	Reduces system viscosity and improves application properties
CNSL-modified epoxy resin	Improves hydrophobicity, flexibility, and adhesion
CNSL-based epoxy curing agent	Improves toughness, wet adhesion, and water resistance
CNSL-based Mannich base	Improves low-temperature curing and applicability on damp surfaces
Raw material for waterborne epoxy curing agents	Used in the design of waterborne protective coating systems

3.3 CNSL-based polyurethane polyols

CNSL itself is not a typical polyol, but CNSL-based hydroxyl-containing polyols can be prepared through phenolic resin formation, hydroxylation, epoxide ring-opening, Mannich reaction, or other methods, and then used in polyurethane resins. Polyurethane, or PU, is an important resin system widely used in coatings, adhesives, sealants, and elastomers. Functionally modified CNSL-based polyols can be used in PU coatings, adhesives, and foam materials.

Note: Raw CNSL or cardanol usually cannot be directly regarded as equivalent to conventional polyether or polyester polyols. In actual PU systems, hydroxylation, epoxide ring-opening, phenolic resin formation, Mannich reaction, or other functionalization methods are generally required to increase hydroxyl functionality and improve reaction controllability.

CNSL Structural Contribution	Effect on PU Systems
Long-chain alkyl groups	Improve flexibility and hydrophobicity
Phenolic aromatic structure	Improves heat resistance and cohesion
Adjustable hydroxyl value	Controls soft/hard segment structure and crosslink density
Natural origin	Increases the proportion of renewable content
Internal plasticizing effect	Improves low-temperature flexibility and coating-film toughness

3.4 CNSL-modified alkyd resins

Alkyd resins are usually prepared from polyols, polyacids, and fatty acids, and are important film-forming resins in traditional coatings. CNSL or cardanol can be used to modify alkyd resins, using their phenolic hydroxyl groups, aromatic rings, and long-chain unsaturated structures to improve coating-film performance.

Modification Direction	Possible Effect
Introduction of hydrophobic long chains	Improves water resistance and flexibility
Introduction of phenolic structures	Improves adhesion and cohesive strength
Use of unsaturated side chains	Participates in oxidative drying or subsequent crosslinking
Partial replacement of oils or phenolic raw materials	Increases bio-based content
Adjustment of drying and hardness	Affects surface drying, through drying, and final film properties

4 Application Directions of CNSL in Coatings

4.1 Protective coatings, epoxy flooring, and industrial coatings

CNSL derivatives are widely used in protective coatings, epoxy flooring, and industrial coatings. The main reason is that their hydrophobic long chains, phenolic structures, and reactive groups help improve coating-film adhesion, water resistance, flexibility, and application properties.

Application Requirement	Role of CNSL Derivatives
Application properties	CNSL-based reactive diluents can reduce viscosity and improve leveling and high-solids application
Wet adhesion	CNSL-based curing agents help improve adhesion to complex substrates or damp surfaces
Flexibility	C15 long chains can reduce brittleness in epoxy systems
Water resistance	Hydrophobic side chains reduce water sensitivity
Corrosion protection	Improves barrier properties, adhesion stability, and coating-film integrity
Curing adjustment	CNSL-based curing agents can change curing speed and pot life
Bio-based content	Increases the proportion of renewable content in the resin

4.2 PU coatings, adhesives, and sealants

CNSL-based polyols can be used in PU coatings, adhesives, and sealants. Their long-chain structures help improve flexibility and hydrophobicity, making them suitable for systems that require water resistance, toughness, and adhesion. For CNSL-based PU materials, attention should also be paid to hydroxyl value, functionality, viscosity, isocyanate reactivity, and final crosslink density.

Application Direction	Key Performance Concerns
PU coatings	Adhesion, flexibility, water resistance, abrasion resistance
Adhesives	Initial tack, cohesive strength, water resistance, and flexibility
Sealants	Low-temperature flexibility, water resistance, and durability
Elastomeric coatings	Elongation, recovery, and crack resistance

4.3 Applications in waterborne coatings

CNSL derivatives can also be used in waterborne coating systems, especially waterborne epoxy curing agents, waterborne polyurethane dispersions, and emulsified modified resins. Because CNSL itself is hydrophobic, direct use in waterborne systems usually leads to dispersion and stability issues. Hydrophilic modification, emulsification, or salt formation is therefore required.

Waterborne Application Direction	Key Requirements
Waterborne epoxy curing agents	Water dispersibility, amine value, curing speed, and wet adhesion
Waterborne PU dispersions	Hydroxyl value, hydrophilic groups, particle size, and stability
Waterborne protective coatings	Flash-rust prevention, water resistance, adhesion, and coating-film integrity
Waterborne wood coatings	Transparency, color tone, water resistance, and stain resistance

5 Limitations and Risks in CNSL Applications

5.1 Color and odor

CNSL is usually dark in color and may have a distinctive odor. Even after distillation and refining, some derivatives may still affect light-colored coatings, transparent coatings, and indoor low-odor coatings. CNSL derivatives are more suitable for dark protective coatings, industrial coatings, or systems with less stringent color requirements. When used in light-colored systems, high-purity, low-color products should be selected, and yellowing resistance and odor should be evaluated.

Risk	Effect on Coatings
Dark color	Not suitable for highly transparent, light-colored, or white systems
Noticeable odor	Affects indoor coatings, furniture coatings, and consumer-product coatings
Color darkening during heat treatment	Color may further darken during reaction or processing
Impurity-related appearance issues	May cause darkening, gloss loss, or coating-film defects

5.2 Composition and batch stability

The composition of CNSL is affected by extraction method, heat-treatment conditions, degree of distillation and refining, origin, and storage conditions. Natural CNSL, technical CNSL, and distilled CNSL have different compositions, which can lead to differences in reactivity, viscosity, color, and final resin performance.

Influencing Factor	Possible Result
Extraction method	Different ratios of anacardic acid, cardanol, and cardol
Degree of heat treatment	Changes in decarboxylation degree and polymerized by-product content
Distillation and refining	Changes in cardanol content, color, and odor
Storage conditions	Oxidation, viscosity increase, or color darkening
Origin differences	Variations in side-chain unsaturation and impurity content

5.3 Difficulty of reaction control

CNSL contains phenolic hydroxyl groups, unsaturated bonds, and long-chain structures, allowing it to undergo multiple types of reactions. However, this also makes reaction control more complex. If reaction conditions are not properly controlled, abnormal viscosity, gelation, color darkening, or functionality deviation may occur. When CNSL derivatives are used in reactive coatings, hydroxyl value, amine value, epoxy value, acid value, viscosity, color, volatile content, and active component content should be clearly defined.

Reaction Risk	Possible Effect
Unstable functionality	Affects curing speed and crosslink density
Side reactions	Cause color darkening, viscosity increase, or gelation
Oxidation of unsaturated bonds	Affects storage stability and coating-film appearance
Fluctuations in hydroxyl value or amine value	Affect PU or epoxy system formulation ratios
Incomplete reaction	Causes residual free components and odor problems

5.4 Performance balance issues

The long-chain structure of CNSL is usually beneficial for flexibility and hydrophobicity, but it may also reduce hardness, glass transition temperature, and heat resistance. The aromatic phenolic structure is beneficial for cohesive strength and reactivity, but it may also cause color and yellowing issues.

Improvement Direction	Possible Side Effect
Improved flexibility	Hardness and heat resistance may decrease
Improved hydrophobicity	Dispersion in waterborne systems becomes more difficult
Reduced viscosity	Chemical resistance and crosslink density may change
Increased bio-based content	Cost, color, and odor need to be reassessed
Increased reactivity	Storage stability and pot life may become shorter

6 Selection and Validation Methods for CNSL

6.1 Raw material indicators

Indicator	Evaluation Significance
Cardanol content	Determines reactivity and product grade
Anacardic acid content	Affects acid value, reaction route, and stability
Cardol and 2-methylcardol content	Affects reactivity, color, and batch stability
Color	Determines suitability for light-colored or transparent systems
Viscosity	Affects application, reaction, and formulation processing
Acid value	Affects water resistance, reactivity, and storage stability
Hydroxyl value	Important for PU polyols and reactive resin design
Amine value	Important for epoxy curing agent design
Epoxy value	Important for epoxidized CNSL derivatives
Moisture and volatile content	Affect curing, odor, and storage stability

6.2 Formulation compatibility

Whether CNSL derivatives can be used in coatings depends mainly on their compatibility with the main resin, curing agent, pigments and fillers, solvent, or waterborne system.

Compatibility Item	Evaluation Criteria
Compatibility with the main resin	Whether turbidity, precipitation, phase separation, or gloss reduction occurs
Matching with the curing agent	Whether curing speed, pot life, and hardness development are appropriate
Compatibility with pigments and fillers	Whether dispersion, settling, and anticorrosive pigment stability are affected
Compatibility with solvents	Whether complete dissolution occurs and whether application viscosity is affected
Compatibility with waterborne systems	Particle size, pH, freeze–thaw stability, heat-storage stability, and dilution stability

Although the hydrophobic long chains of CNSL derivatives are beneficial for water resistance, they may also cause dispersion difficulties in waterborne systems. When CNSL derivatives are used in waterborne coatings, hydrophilic modification and emulsion stability are particularly important.

6.3 Coating-film performance validation

Whether CNSL derivatives are suitable for coatings ultimately needs to be confirmed through coating-film performance testing.

Test Item	Evaluation Purpose
Drying or curing time	Evaluates application rhythm and complete curing
Hardness	Evaluates crosslink density and surface scratch resistance
Flexibility	Evaluates toughness improvement brought by long-chain structures
Adhesion	Evaluates substrate bonding and intercoat bonding
Water resistance	Evaluates whether the hydrophobic structure and film compactness are effective
Salt-spray resistance	Evaluates corrosion resistance of protective coatings
Chemical resistance	Evaluates resistance to acids, alkalis, solvents, and oils
Yellowing resistance	Evaluates color and long-term appearance stability
Storage stability	Evaluates whether thickening, phase separation, precipitation, or discoloration occurs

6.4 Unsuitable application scenarios

CNSL offers advantages in natural origin and reactivity, but it is not suitable for all coating scenarios.

Unsuitable Scenario	Main Reason
High-whiteness and colorless transparent coatings	CNSL has relatively high color and yellowing risks
Extremely low-odor indoor coatings	Odor and residual components need to be strictly controlled
Unmodified waterborne systems	CNSL is hydrophobic and has insufficient dispersion stability
High-hardness and high-heat-resistance systems	Long-chain structures may reduce hardness and heat resistance
High-standard electronic or optical coatings	Color, impurities, and ionic control are relatively difficult
Mass production without sufficient quality control	Batch fluctuations may affect reaction behavior and coating-film performance

7 Representative Chemical Products Related to Cashew Nut Shell Liquid (CNSL)

Note: Some products listed in the tables are high-purity reference standards, saturated homologues, or reaction model compounds representing typical CNSL components. They are suitable for structural studies, analytical comparison, and formulation validation. Natural CNSL is generally a complex mixture of homologues with different degrees of unsaturation and various phenolic components.

Table 1 Representative CNSL Components and Phenolic Reaction Raw Materials

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Representative CNSL component	16611-84-0	A275817	Anacardic acid	Moligand™, ≥98%	Used for compositional analysis of cashew nut shell liquid, structural studies of anacardic acid, research on decarboxylation to cardanol, and studies of bio-based phenolic resins
Representative CNSL component	3158-56-3	P339807	5-Pentadecylresorcinol, saturated homologue of cardol-type compounds	≥95%	Used as a saturated structural reference for cardol-type compounds, for compositional analysis of cashew nut shell liquid, studies of phenolic reaction activity, and research on bio-based resin modification
Representative CNSL component	501-24-6	P1373804	3-Pentadecylphenol / Hydrogenated cardanol	≥90% (mixture of isomers)	Used for structural studies of hydrogenated cardanol, modification with saturated hydrophobic phenolic compounds, epoxy resin modification, and research on phenolic resin and polyurethane raw materials
Phenolic resin raw material	108-95-2	P100770	Phenol	≥99.5% (GC)	Used as a reference for CNSL-modified phenolic resins, phenolic condensation reactions, resin curing, and coating-film resistance studies
Phenolic / Mannich reaction raw material	50-00-0	F111936	Formaldehyde solution	ACS, 37 wt.% in H₂O, contains 10–15% methanol as stabilizer	Used for CNSL phenolic condensation, Mannich base preparation, epoxy curing-agent raw materials, and bio-based resin synthesis studies
Phenolic / Mannich reaction raw material	30525-89-4	C104188	Paraformaldehyde	AR	Used for CNSL phenolic resins, Mannich reactions, preparation of curing-agent intermediates, and reaction-condition studies
Amine raw material for Mannich reaction	124-40-3	D298752	Dimethylamine (DMA)	Moligand™, 30% solution in methanol	Used for CNSL-based Mannich bases, epoxy curing-agent intermediates, amination reactions, and low-temperature curing system studies
Amine raw material for Mannich reaction	100-46-9	B108477	Benzylamine	AR, ≥99%	Used for CNSL phenalkamine curing agents, Mannich reactions, epoxy curing systems, and wet-adhesion performance studies

Table 2 Products Related to Epoxy Resins, Epoxidation, and Amine Curing Systems

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Epoxidation reaction raw material	106-89-8	E108184	Epichlorohydrin	≥99.5% (GC)	Used for cardanol glycidyl ether, CNSL-based epoxy diluents, epoxy resin synthesis, and reactive diluent studies
Epoxy resin reference raw material	80-05-7	B108652	Bisphenol A	Moligand™, ≥99% (GC)	Used as a reference for bisphenol A epoxy resins, performance comparison of CNSL-based epoxy materials, and resin structure studies
Epoxy resin reference standard	1675-54-3	B131786	Bisphenol A diglycidyl ether (BADGE)	Moligand™, ≥85%	Used as a reference for epoxy resin curing, evaluation of CNSL-based epoxy modification, crosslink density, and coating-film resistance studies
Epoxy curing-agent raw material	107-15-3	E112643	Ethylenediamine, regulated explosive precursor	Rectified grade, ≥99.5%	Used for epoxy curing agents, CNSL-based phenalkamine systems, amine value comparison, and coating-film curing reaction studies
Epoxy curing-agent raw material	111-40-0	D100059	Diethylenetriamine	≥99%	Used for epoxy curing agents, CNSL-modified curing systems, low-temperature curing, and water-resistant adhesion studies
Epoxy curing-agent raw material	112-24-3	T103762	Triethylenetetramine (TETA)	Chemically pure (CP), ≥68%	Used for epoxy resin curing, CNSL-based curing-agent references, pot life, and hardness development studies
Epoxy curing-agent raw material	2855-13-2	A104545	Isophorone diamine, mixture of cis/trans isomers (IPDA)	≥99%	Used for epoxy curing agents, CNSL-modified protective coatings, water resistance, chemical resistance, and low-color systems
Epoxy curing-agent raw material	1477-55-0	X107227	m-Xylylenediamine (MXDA)	≥99%	Used for epoxy curing agents, CNSL-based protective coatings, wet adhesion, chemical resistance, and fast-curing systems

Table 3 Products Related to Polyurethane and Waterborne Systems

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Polyurethane polyol	25322-69-4	P103212	Polypropylene glycol (PPG)	Average molecular weight 4000	Used for CNSL-based polyurethane blending, flexible coatings, adhesives, sealants, and elastomeric coating-film studies
Polyurethane chain extender	110-63-4	B1508458	1,4-Butanediol (BDO)	Anhydrous grade, ≥99%	Used for polyurethane chain extension, hard-segment adjustment in CNSL-based polyurethane, elastomeric coatings, and adhesive studies
Polyurethane chain extender	107-21-1	E103322	Ethylene glycol	≥99% (GC)	Used for polyurethane chain extension, polyester polyol synthesis, structural adjustment of CNSL-based resins, and coating-film performance studies
Aliphatic cyclic isocyanate	4098-71-9	I109582	Isophorone diisocyanate, mixture of isomers (IPDI)	≥99%	Used for CNSL-based polyurethane coatings, waterborne polyurethane dispersions, weather-resistant coatings, and low-yellowing systems
Aromatic isocyanate	101-68-8	M106783	4,4′-Methylenebis(phenyl isocyanate) (MDI)	≥98%	Used for CNSL-based polyurethane, adhesives, elastomeric materials, hard-segment structures, and mechanical performance studies
Internal emulsifying monomer for waterborne polyurethane	4767-03-7	B104539	2,2-Bis(hydroxymethyl)propionic acid (DMPA)	≥98%	Used for CNSL-based waterborne polyurethane, introduction of hydrophilic groups, emulsion stability, and waterborne coating-film studies
Neutralizing agent for waterborne systems	121-44-8	T140677	Triethylamine	Anhydrous grade, ≥99.5%, water ≤50 ppm	Used for DMPA neutralization, waterborne polyurethane dispersion, CNSL-based waterborne resins, and emulsion stability studies
Neutralizing agent / amino alcohol for waterborne systems	108-01-0	D109080	N,N-Dimethylethanolamine (DMEA)	Rectified grade, ≥99.5%	Used for neutralization of waterborne resins, CNSL-based waterborne epoxy or polyurethane systems, dispersion stability, and acid value adjustment
Amino alcohol for waterborne systems	105-59-9	M105603	N-Methyldiethanolamine	≥99%	Used for waterborne polyurethane, cationic resins, CNSL-based waterborne systems, and neutralizable reactive resins

Table 4 Products Related to Alkyd, Polyester, and Polyol Modification

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Alkyd / polyester anhydride raw material	85-44-9	P116466	Phthalic anhydride	Guaranteed reagent, ≥99%	Used for CNSL-modified alkyd resins, polyester resins, and studies of coating-film hardness, gloss, and drying performance
Alkyd / polyester anhydride raw material	108-31-6	M116389	Maleic anhydride	AR, ≥99% (GC)	Used for CNSL-modified alkyd resins, introduction of unsaturated structures, waterborne modification, and reactive resin studies
Polyester / alkyd dibasic acid	124-04-9	A108266	Adipic acid	Ultra-pure grade, ≥99.5% (HPLC)	Used for polyester polyols, flexible alkyd resins, CNSL-based polyurethane, and coating-film toughness adjustment studies
Alkyd / polyester polyol	56-81-5	G358402	Glycerol	≥99%	Used for CNSL-modified alkyd resins, polyester polyols, esterification reactions, and structural adjustment of coating resins
Alkyd / polyester polyol	77-99-6	T110597	Trimethylolpropane (TMP)	≥98%	Used for CNSL-modified alkyd resins, polyurethane polyols, crosslink density adjustment, and coating-film hardness studies
Alkyd / polyester polyol	115-77-5	P103696	Pentaerythritol, regulated explosive precursor	AR, ≥98%	Used for CNSL-modified alkyd resins, high-functionality polyester resins, and studies of hardness and water resistance

Note: The products listed above are representative Aladdin products. For more product specifications, please search by “product name / CAS / catalog number” on the Aladdin website.

References

[1] Kyei S. K., Eke W. I., Nagre R. D., Mensah I., Akaranta O. A Comprehensive Review on Waste Valorization of Cashew Nutshell Liquid: Sustainable Development and Industrial Applications. Cleaner Waste Systems, 2023, 6, 100116.

[2] Kumar P. P., Paramashivappa R., Vithayathil P. J., Subba Rao P. V., Srinivasa Rao A. Process for Isolation of Cardanol from Technical Cashew (Anacardium occidentale L.) Nut Shell Liquid. Journal of Agricultural and Food Chemistry, 2002, 50(16), 4705–4708.

[3] Ocasio-Malavé C., et al. Isolation of Cardanol Fractions from Cashew Nutshell Liquid (CNSL): A Sustainable Approach. Sustainable Chemistry, 2024, 5(2), 6.

[4] Rojtman E., Denis M., Sirvent C., Lapinte V., Caillol S., Briou B. Polyols from Cashew Nut Shell Liquid (CNSL): Corner-Stone Building Blocks for Innovative Polyurethanes. Polymer Chemistry, 2024.

[5] Cardolite Corporation. Cashew Nutshell Liquid-Based Epoxy Products: Curing Agents, Diluents and Modifiers for Protective and Industrial Coatings. Technical Literature.

[6] Denis M., Totée C., Le Borgne D., Caillol S., Negrell C. Cardanol-Modified Alkyd Resins: Novel Route to Make Greener Alkyd Coatings. Progress in Organic Coatings, 2022, 172, 107087.

[7] Baroncini E. A., Yadav S. K., Palmese G. R., Stanzione J. F. Recent Advances in Bio-Based Epoxy Resins and Bio-Based Epoxy Curing Agents. Journal of Applied Polymer Science, 2016, 133(45), 44103.

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