C36 Dimer acid is a high–molecular weight dicarboxylic fatty acid obtained by the controlled dimerization of unsaturated C18 fatty acids, typically sourced from renewable vegetable oils such as tall oil or soybean oil.

C36 Dimer acid's predominantly branched, flexible aliphatic structure with two carboxyl functional groups results in low crystallinity, excellent flexibility, and enhanced compatibility with a wide range of polymers and resins.

C36 Dimer acid is widely used in polyamides, polyesters, hot-melt and pressure-sensitive adhesives, coatings, and elastomers, where it imparts toughness, hydrophobicity, moisture resistance, and long-term durability.

CAS Number: 61788-89-4

EC Number: 500-148-0

Molecular Formula: C36H64O4

Molecular Weight: Approx. 560 g/mol

Synonyms: Monobasic acid, C36 DIMER ACID, C36 Dimer acidC, Trimericfattyacid, FATTYACIDS,DIMERACIDS, High purity dimer acid, C18-Unsatd.fattyacidsdimers, Fatty acids, diMeracids, C18, Dimerfettsure, C18, ungesttigt, C18-unsaturated fatty acid dimers, Haridimer 250K, 37317-30-9, 123997-55-7, 872420-55-8, 1450829-02-3, Fatty acids C18-unsatd dimers, (Octadecadienoic acid) dipolymer, Dilinoleic acid, DTXSID70873445, 1572670-81-5, 9-((3Z)-Non-3-en-1-yl)-10-octylnonadecanedioic acid, 9-[(3Z)-non-3-en-1-yl]-10-octylnonadecanedioic acid, RefChem:1074880, DTXCID408062, C36 Dimer acid 9-[(3Z)-non-3-en-1-yl]-10-octylnonadecanedioic acid nonadecanedioic acid, 9-[(3Z)-3-nonenyl]-10-octyl- 9-[(3Z)-3-Nonen-1-yl]-10-octylnonadecanedioic acid Nonadecanedioic acid, 9-[(3Z)-3-nonen-1-yl]-10-octyl-, Dibasic Acid, C36 Dimer acid, Unsaturated fatty acids,C18,dimers, Fatty acids,C18-unsatd.,dimers, Fatty acids,dimer acids,C18, UCN 1355, Empol 1014, Empol 10-14, Empol 1003, Haridimer 300, Empol 1020, Empol 1061, C36 dimer acid, Empol 1026, Radiacid 0970, Unidyme 10, Pripol 1012LQ

C36 Dimer acid is a long-chain dicarboxylic fatty acid produced by the controlled dimerization of unsaturated C18 fatty acids, typically derived from renewable vegetable oils.

C36 Dimer acid is characterized by its high molecular weight, flexible aliphatic structure, and two carboxyl functional groups, which provide excellent reactivity and compatibility in polymer systems.

C36 Dimer acid is widely used in the production of polyamides, polyester resins, hot-melt and pressure-sensitive adhesives, coatings, elastomers, and ink binders, where it imparts flexibility, toughness, hydrophobicity, and improved chemical and moisture resistance.

C36 Dimer acid's low crystallinity, good thermal stability, and renewable origin make it a key building block for high-performance and sustainable industrial formulations.

C36 Dimer acid is a colorless transparent liquid.

The relative density of C36 Dimer acid is 0.95, and the flash point is 280-350 °C.

C36 Dimer acid, refers to the natural oil linoleic acid as the main component of the straight chain of unsaturated fatty acids or unsaturated fatty acid esters in the white clay catalysis, the dimer is self-polycondensed by a Diels-Alder cycloaddition reaction or the like.

C36 Dimer acid is a mixture of isomers in which the main components are dimers, small amounts of trimers or multimers and minor amounts of unreacted monomers.

C36 Dimer acid refers to the dimerization of linear unsaturated fatty acid or unsaturated fatty acid ester with linoleic acid of natural oil as the main component, which is self-condensed through Diels-Alder cycloaddition reaction under the catalysis of clay.

C36 Dimer acid is a mixture of various isomers, in which the main components are dimers, small amounts of trimers or multimers, and traces of unreacted monomers.

C36 Dimer acid is an important oleochemical that is widely used in coatings, surfactants, lubricants, printing inks, hot melt adhesives and other industries.

C36 Dimer acid is dicarboxylic acids produced by dimerizing unsaturated fatty acids obtained from tall oil, oleic acid, canola oil or cottonseed oil, usually on clay catalysts.

C36 Dimer acid has similar reactivity with general fatty acids, can form metal salts with alkali metals, can be derived into acyl chloride, amide, ester, diamine, diisocyanate and other products.

C36 Dimer acid with long chain alkyl and ring structure, and a variety of solvents have good miscibility, good thermal stability, in winter is not curing, and vapor pressure still has corrosion resistance, good lubrication.

Therefore, C36 Dimer acid is widely used as an additive for fuel oil, lubricating Chemicalbook oil, calender oil, hydraulic oil, cutting oil, etc.

C36 Dimer acid is a dimerized organic carboxylic acid derivative, specifically a C36 Dimer acid formed from the polymerization of unsaturated fatty acids.

At room temperature, C36 Dimer acid typically exists as a viscous, pale yellow to amber-colored liquid or semi-solid with a mild, characteristic fatty acid odor.

C36 Dimer acid belongs to the class of long-chain dicarboxylic acids and exhibits amphiphilic properties due to the presence of two carboxylic acid functional groups separated by a long aliphatic chain structure.

C36 Dimer acid was first synthesized in the mid-20th century through the thermal or catalytic dimerization of unsaturated C18 fatty acids such as oleic acid.

The process generally involves heating the monomeric fatty acid under controlled conditions in the presence of a catalyst like clay or acidic ion exchange resins.

This reaction leads to the formation of a cycloaliphatic ring system connecting two fatty acid chains, resulting in a molecule with two terminal carboxylic acid groups.

While primarily produced synthetically, trace amounts may be found in certain natural oils where partial dimerization occurs during extraction or refining processes.

Industrially, C36 Dimer acid is prepared via the dimerization of distilled tall oil fatty acids under elevated temperatures and pressure, followed by purification through distillation and filtration steps.

C36 Dimer acid is formed by the controlled dimerization (typically via Diels–Alder / cycloaddition processes) of unsaturated fatty acids (e.g. oleic, linoleic) obtained from natural oils (e.g. tall oil).

C36 Dimer acid is a dicarboxylic acid with two long hydrocarbon chains linked via a central ring or bridging moiety.

C36 Dimer acid refers to a dimer acid whose nominal formula corresponds to ~36 carbons in the total dimer skeleton (i.e. two ~C18 chains joined).

C36 Dimer acid is one of the most common dimer acids in commercial use.

C36 Dimer acid is often supplied as a mixture / isomeric blend (i.e. the “dimer acid” product is not a single pure isomer) — minor amounts of monomers, trimers, or other oligomers may be present.

C36 Dimer acid, or dimerized fatty acids, are dicarboxylic acids prepared by dimerizing unsaturated fatty acids obtained from tall oil, usually on clay catalysts.

C36 Dimer acid is a light yellow or yellow viscous transparent liquid.

C36 Dimer acid usually contains predominantly a dimer of oleic acid.

C36 Dimer acid is a corresponding material where the resulting molecule consists of three fatty acid molecules.

C36 Dimer acid is a high–molecular weight dicarboxylic acid obtained by the controlled dimerization of unsaturated C18 fatty acids, typically sourced from renewable vegetable oils such as tall oil or soybean oil.

The dimerization process produces a predominantly branched, flexible aliphatic structure containing two carboxyl functional groups, which distinguishes C36 Dimer acid from conventional linear diacids.

This unique molecular architecture results in low crystallinity, excellent flexibility, and enhanced compatibility with a wide range of polymers and resins.

C36 Dimer acid is widely used as a key raw material in the manufacture of polyamides, polyesters, alkyd resins, and epoxy-modified systems, where it imparts toughness, elasticity, and improved impact resistance.

In adhesive formulations, particularly hot-melt and pressure-sensitive adhesives, C36 Dimer acid contributes to superior adhesion, flexibility at low temperatures, and resistance to moisture and chemicals.

C36 Dimer acid's hydrophobic backbone also enhances water resistance and durability in coatings, sealants, and elastomers.

Due to its long hydrocarbon chain and bifunctional reactivity, C36 Dimer acid enables the production of polymers with improved thermal stability, reduced brittleness, and excellent aging performance.

The renewable origin of the raw materials further supports C36 Dimer acid's use in sustainable and bio-based formulations.

These combined properties make C36 Dimer acid an important building block in high-performance industrial applications requiring flexibility, durability, and long-term stability.

Uses of C36 Dimer Acid:

C36 Dimer acid is widely used as a key intermediate in the production of flexible polyamides, polyesters, and alkyd resins, where it imparts toughness, elasticity, and reduced brittleness.

In adhesive applications, particularly hot-melt and pressure-sensitive adhesives, C36 Dimer acid improves adhesion, low-temperature flexibility, and resistance to moisture and chemicals.

C36 Dimer acid is also incorporated into coatings, sealants, printing inks, and elastomer systems to enhance hydrophobicity, durability, and long-term performance, making it a valuable building block for high-performance and bio-based industrial formulations.

C36 Dimer acid is mainly used as a modifier for polyamide resin and epoxy resin and an additive for fuel oil, lubricating oil and cutting oil.

C36 Dimer acid serves a crucial role in the oleochemical industry, finding widespread applications across various sectors such as coatings, surfactants, lubricants, printing inks, and hot melt adhesives.

C36 Dimer acid is the result of the dimerization process involving linear unsaturated fatty acids or unsaturated fatty acid esters, primarily utilizing linoleic acid derived from natural oils.

This reaction, which occurs via a Diels-Alder cycloaddition mechanism catalyzed by clay, produces a complex mixture predominantly consisting of dimeric isomers, with minor quantities of trimers or multimers, as well as trace amounts of unreacted monomers.

C36 Dimer acid and amine will react to produce much different molecular weight polyamide resin.

C36 Dimer acid is mainly used to make graver or flexo printing ink, epoxy paint, the curing agent and the epoxy cementing material, lubricant.

C36 Dimer acid is used to make hot melt adhesive, which is widely used to make thermoplastic product and joint of electric cable in the posts and telecommunications, the communication equipment.

C36 Dimer acid and amine can produce various kinds of polyamides with different molecular weight with the participation of different additives (excipients), which are widely used in the manufacture of plastic gravure printing ink.

C36 Dimer acid reacts with polyamines to form polyamides with active amines, which are widely used in the manufacture of two-component epoxy paint, curing agent and epoxy binder.

The cured products have good mechanical and electrochemical properties.

In addition, C36 Dimer acid can also be used to manufacture various low-temperature and low-pressure special lubricants and metal processing oils.

C36 Dimer acid is used in manufacturing hot melt adhesives, and widely used in manufacturing thermoplastic products of electronics and electrical appliances, automotive interiors, shoes, etc.

C36 Dimer acid is mainly used as polyamide resin, but also used in oil additives, surfactants, synthetic paints, inks, adhesives, curing agents, etc.

C36 Dimer acid is an important oleochemical that is widely used in coatings, surfactants, lubricants, printing inks, hot melt adhesives and other industries.

Polyamide Resins uses:

C36 Dimer acid provides flexibility and adhesion in coatings and hot-melt adhesives.

C36 Dimer acid is used in both reactive polyamides (epoxy curing agents) and non-reactive polyamides.

C36 Dimer acid enhances toughness and hydrolytic stability.

Lubricants & Oil Additives uses:

C36 Dimer acid delivers thermal stability and corrosion inhibition.

C36 Dimer acid functions as performance additive in metalworking fluids.

C36 Dimer acid improves high-temperature performance.

Coatings & Adhesives uses:

C36 Dimer acid enhances flexibility and chemical resistance in alkyd resins.

Key component in durable hot-melt adhesives.

C36 Dimer acid improves weatherability in protective coatings.

Action Mechanism of C36 Dimer Acid:

C36 Dimer acid functions through its long, flexible aliphatic backbone combined with two reactive carboxyl groups, which enables it to chemically incorporate into polymer chains via esterification or amidation reactions.

The bulky, branched C36 structure disrupts regular molecular packing, reducing crystallinity and increasing chain mobility, which results in enhanced flexibility, toughness, and impact resistance in the final material.

At the same time, the carboxyl groups provide effective crosslinking and strong intermolecular interactions, improving adhesion, cohesion, and durability.

This combination allows C36 Dimer acid to act as a flexibility-imparting, toughness-enhancing building block while maintaining chemical resistance, hydrophobicity, and long-term stability in adhesives, resins, coatings, and polymer systems.

Production of C36 Dimer Acid:

C36 Dimer acid is produced by the controlled dimerization of unsaturated C18 fatty acids, which are typically derived from renewable vegetable oil sources such as tall oil or soybean oil.

The process involves heat and clay-based catalysts that promote Diels–Alder–type and other coupling reactions, converting monomeric fatty acids into predominantly C36 dimer molecules with a branched, flexible structure.

After dimerization, the reaction mixture is subjected to distillation and purification steps to remove unreacted monomers, trimers, and low-boiling components, resulting in a high-purity dimer acid fraction.

The final product is standardized to meet specific acid value, viscosity, and color requirements for use in adhesives, resins, coatings, and polymer applications.

Synthesis of C36 Dimer Acid:

C36 Dimer acid is synthesized by the thermal and catalytic dimerization of unsaturated C18 fatty acids (such as oleic and linoleic acid) obtained from renewable vegetable oil feedstocks.

In practice, the fatty acid mixture is heated and contacted with acid-activated clay catalysts, which promote intermolecular coupling reactions, including Diels–Alder–type additions and related rearrangements, to form predominantly C36 dimer structures with branched, flexible hydrocarbon backbones and two terminal carboxyl groups.

The crude product typically contains residual C18 monomers and higher oligomers (trimers), so C36 Dimer acid is refined by vacuum distillation and fractionation to achieve the desired dimer content, acid value, viscosity, and color.

The resulting C36 Dimer acid is then filtered and quality-controlled to ensure consistent performance in polyamide, polyester, adhesive, and coating formulations.

Stability and Reactivity of C36 Dimer Acid:

Chemical stability:

C36 Dimer acid is chemically stable under normal conditions of use, handling, and storage.

Reactivity:

Reacts with alcohols, amines, and epoxides through C36 Dimer acid's carboxyl groups to form esters, amides, and modified resins; no hazardous reactions under normal conditions.

Conditions to avoid:

Excessive heat, open flames, and prolonged exposure to strong oxidizing conditions.

Incompatible materials:

Strong oxidizing agents, strong bases.

Hazardous decomposition products:

Thermal decomposition may produce carbon oxides (CO, CO₂) and irritating organic fumes.

Handling and Storage of C36 Dimer Acid:

Handling:

Handle in accordance with good industrial hygiene and safety practices.

Avoid prolonged skin contact and heating above recommended processing temperatures.

Storage:

Store in a cool, dry, well-ventilated area in tightly closed containers.

Storage conditions:

Protect from moisture and contamination.

Packaging materials:

Carbon steel, stainless steel, or approved lined containers.

Shelf life:

Long shelf life when stored under recommended conditions.

First Aid Measures of C36 Dimer Acid:

Inhalation:

Not expected to be hazardous under normal conditions; if vapors or fumes are inhaled, move the person to fresh air and seek medical attention if symptoms persist.

Skin contact:

Wash thoroughly with soap and water.

Remove contaminated clothing and wash before reuse.

Eye contact:

Rinse cautiously with water for several minutes.

Seek medical attention if irritation persists.

Ingestion:

Rinse mouth with water.

Do not induce vomiting.

Seek medical advice if discomfort occurs.

Most important symptoms:

Mild skin or eye irritation upon prolonged contact.

Firefighting Measures of C36 Dimer Acid:

Suitable extinguishing media:

Foam, dry chemical powder, carbon dioxide (CO₂), or water spray.

Specific hazards:

Combustible organic material; may emit irritating fumes when burning.

Protective equipment for firefighters:

Self-contained breathing apparatus and full protective clothing.

Special precautions:

Cool containers exposed to fire with water spray.

Prevent firefighting runoff from entering drains.

Accidental Release Measures of C36 Dimer Acid:

Personal precautions:

Avoid direct contact with spilled material.

Use appropriate personal protective equipment.

Environmental precautions:

Prevent large quantities from entering drains, soil, or watercourses.

Methods for cleanup:

Absorb with inert material such as sand or vermiculite.

Collect in suitable containers for disposal according to local regulations.

Exposure Controls / Personal Protective Equipment of C36 Dimer Acid:

Occupational exposure limits:

Not established.

Engineering controls:

Adequate general ventilation recommended.

Personal protective equipment (PPE):

Respiratory protection:

Not normally required; use organic vapor respirator if heated or mist is generated.

Hand protection:

Chemical-resistant gloves recommended.

Eye protection:

Safety glasses or goggles.

Skin protection:

Protective work clothing for prolonged handling.

Hygiene measures:

Wash hands after handling.

Avoid eating, drinking, or smoking in work areas.

Identifiers of C36 Dimer Acid:

CAS number: 61788-89-4

EC / EINECS number: 262-988-1

Molecular formula: Approx. C36H64O4

Molecular weight: Approx. 560 g/mol

Chemical family: Fatty acid derivatives / Dicarboxylic acids

Physical form: Viscous liquid or semi-solid

Appearance: Amber to light brown

Odor: Mild, fatty odor

Class: Dimer Acids and Trimer Acids

Market: Oleochemicals

CAS: 61788-89-4

EINECS: 500-148-0

Molecular Formula: C36H64O4

Molar Mass: 560.91

InChIKey: AMOKUAKXKXBFIW-WJDWOHSUSA-N

SMILES: C(O)(=O)CCCCCCCC(CC/C=CCCCCC)C(CCCCCCCC)CCCCCCCCC(O)=O

LogP: 1–14.81 at pH2

Indirect Additives used in Food Contact Substances: FATTY ACIDS(C18), UNSATURATED, DIMERS

FDA UNII: 04P17590AP

EPA Substance Registry System: C18-Unsatd. fatty acids dimers (61788-89-4)

CAS No.: 61788-89-4

Chemical Name: C36 Dimer acid

Properties of C36 Dimer Acid:

Molecular Weight: 564.9 g/mol

XLogP3-AA: 14.7

Hydrogen Bond Donor Count: 2

Hydrogen Bond Acceptor Count: 4

Rotatable Bond Count: 32

Exact Mass: 564.51176065 Da

Monoisotopic Mass: 564.51176065 Da

Topological Polar Surface Area: 74.6 Ų

Heavy Atom Count: 40

Complexity: 585

Isotope Atom Count: 0

Defined Atom Stereocenter Count: 0

Undefined Atom Stereocenter Count: 2

Defined Bond Stereocenter Count: 1

Undefined Bond Stereocenter Count: 0

Covalently-Bonded Unit Count: 1

Compound Is Canonicalized: Yes

Physical state: Viscous liquid to semi-solid

Appearance: Amber to light brown

Odor: Mild, fatty odor

Solubility in water: Insoluble

Solubility in organic solvents: Soluble in many organic solvents

Density: Typically lower than water

Acid value: High, reflecting the presence of two carboxyl functional groups

Viscosity: High due to long-chain, branched molecular structure

Melting point: Low; remains flexible at low temperatures

Vapor Pressure: 0-0.029Pa at 25℃

Form: Viscous

LogP: 1-14.81 at pH2

Indirect Additives used in Food Contact Substances: 

FATTY ACIDS(C18), UNSATURATED, DIMERS

FDA UNII: 04P17590AP

EPA Substance Registry System: C18-Unsatd. 

fatty acids dimers (61788-89-4)

Molecular Weight: 564.92

Appearance: Brown, viscous liquid

Density: 0.950 g/cm3

Assay: 70 - 85 % (Dibasic Acid)

Boiling Point: > 260°C

Melting Point: -18°C (pour point)

Flash Point: > 257°C

Odor: Mild fatty

Acid Value: 181 MIN.

Specifications of C36 Dimer Acid:

Acid value: Typically 180–195 mg KOH/g

Saponification value: Typically 185–200 mg KOH/g

Viscosity (25 °C): High; product-dependent and grade-specific

Color (Gardner): Typically 5–8

Moisture content: ≤ 0.5 %

Dimer content: ≥ 75–85 %

Density (25 °C): Approx. 0.90–0.95 g/cm³

Pour point: Low, remains flowable at reduced temperatures