Rubber & tires
- Process role: Co-activator with ZnO; processing/lubricity aid depending on formulation
- Critical parameters: C18/C16; acid value; iodine value; titer; ash; color
OGSCM / TECHNICAL PROCUREMENT INTELLIGENCE
Stearic Acid (C18:0)
Oleochemical Raw Material for Rubber Compounding, Lubricants, Personal Care and Industrial Formulation
Stearic acid (octadecanoic acid) is a C18 saturated fatty acid. Commercial 'stearic acid' is often a controlled C18/C16 fatty-acid blend rather than chemically pure C18 material, so procurement should be based on composition and functional tests - especially acid value, iodine value, titer, color and moisture - not on the product name alone.
High Adsorption Performance
Consistent Quality
Reliable Supply
Flexible Supply Options
Trusted by industries across GCC & MENA
Laboratory & HPLC
Chemical Synthesis
Agrochemicals
Extraction & Purification
CHEMISTRY, MANUFACTURING CONTEXT & MATERIAL BEHAVIOUR
Stearic acid is a long-chain saturated monocarboxylic acid. Commercial material is commonly produced by hydrolysis/splitting of fats or oils followed by hydrogenation and fractionation. In rubber compounding it is particularly important as a co-activator with zinc oxide: zinc stearate species formed in situ participate in sulfur-vulcanization activation and can also influence processing, dispersion and lubrication. This functional role should be stated explicitly for tire and rubber buyers.
PROCESS-ENGINEERING & GRADE-SELECTION CONSIDERATIONS
- For rubber grades, specify fatty-acid distribution (C18/C16), acid value, iodine value, titer, color, moisture/volatile matter and ash. These are more procurement-relevant than a single pure-compound melting point.
- Low iodine value indicates low residual unsaturation and generally better oxidative/color stability for demanding formulations.
- Personal-care, food and pharmaceutical applications require application-specific grade and documentation; industrial rubber grade must not be represented as automatically suitable.
- Storage should prevent contamination, excessive heat and moisture. In hot GCC warehouses, control conditions to avoid caking, deformation of flakes/prills and packaging deterioration.
◎ Technical Specifications
| Property | Value |
|---|---|
Formula | C₁₈H₃₆O₂ |
CAS | 57-11-4 |
Molar mass | 284.48 g/mol |
Appearance | White waxy solid, flakes, beads or powder depending on grade |
Melting point | ~69.3°C for pure stearic acid; commercial grades show grade-dependent titer/melting range |
Density | ~0.94 g/cm³ at 20°C (reference) |
Solubility | Practically insoluble in water; soluble in many organic solvents |
Key commercial distinction | C18/C16 distribution varies by grade |
Typical supply forms | Flakes, beads/prills, powder; 25 kg bags are common but supplier-specific |
INDUSTRIAL APPLICATION MATRIX
PVC / plastics & lubricants
- Process role: Lubricity, release and metal-soap feedstock
- Critical parameters: Purity; color; thermal stability; metal impurities
Personal care & cosmetics
- Process role: Structuring / consistency and surfactant-system raw material
- Critical parameters: Cosmetic grade; odor/color; purity; regulatory documentation
Food / pharma
- Process role: Application-specific excipient or processing uses
- Critical parameters: Only compliant food/pharma grade with required monographs/certificates
Candles / wax / specialty formulations
- Process role: Hardness and melting-behaviour modifier
- Critical parameters: Titer; fatty-acid profile; color
QUALITY CONTROL, COA PARAMETERS & TEST FOCUS
- Acid value | Method/evidence: Titration | Why it matters: Available carboxylic acid / grade consistency
- Iodine value | Method/evidence: Validated titration | Why it matters: Residual unsaturation / oxidative stability
- Titer / solidification point | Method/evidence: Standard producer method | Why it matters: Thermal behaviour and grade identity
- C18 / C16 fatty-acid profile | Method/evidence: GC | Why it matters: Functional grade and batch consistency
- Moisture / volatile matter | Method/evidence: Gravimetric / Karl Fischer as applicable | Why it matters: Storage and processing
- Color | Method/evidence: Lovibond / APHA / producer method | Why it matters: Appearance-sensitive applications
- Ash / inorganic residue | Method/evidence: Gravimetric | Why it matters: Contamination control
STORAGE, HANDLING, MATERIALS COMPATIBILITY & HSE
Stearic acid is comparatively low-hazard under normal industrial use, but molten material can cause thermal burns and fine powder can create nuisance-dust exposure. Use good ventilation, housekeeping, eye protection and gloves appropriate to the physical form and temperature. For food, cosmetic or pharmaceutical use, hygiene and contamination-control requirements are as important as conventional HSE.
PACKAGING, TRANSPORT & SUPPLY PLANNING FOR GCC / MENA
Common industrial packs include lined 25 kg bags, cartons or other producer-specific formats. For GCC/MENA supply, confirm physical form (flakes/prills/powder), palletization, liner, warehouse temperature, protection from contamination and lot traceability.
FREQUENTLY ASKED QUESTIONS
No. Many commercial grades are mixtures rich in stearic and palmitic acids; the fatty-acid profile must be specified.
It works with ZnO in the vulcanization-activation system and can also affect processing and dispersion.
For many industrial grades: fatty-acid profile, acid value, iodine value, titer, color, moisture and ash.
Not by assumption. The intended sector requires the appropriate grade, impurity limits and documentation.
