SINOMER® SMA (Stearyl Methacrylate, also known as Octadecyl Methacrylate, CAS No 32360‑05‑7) is a long‑chain alkyl methacrylate monomer that delivers exceptional hydrophobic properties, flexibility, and low shrinkage. Its C18 side chain imparts unique surface characteristics – low surface energy, excellent water repellency, and superior weatherability – making it an essential building block for high‑performance polymers in coatings, adhesives, textiles, and specialty materials.
SINOMER® SMA is supplied as a white solid to light yellow liquid with high purity (≥98%) and low acid value, ensuring consistent performance in demanding formulations.
| Feature | Benefit |
|---|---|
| Long C₁₈ Hydrophobic Chain | Imparts excellent water repellency, low surface energy, and anti‑soiling properties |
| Low Shrinkage & Low Volatility | Ensures dimensional stability and minimal VOC emissions during processing |
| High Flexibility | Provides outstanding film flexibility and crack resistance |
| Excellent Weather Resistance | Delivers long‑term durability against UV, moisture, and temperature fluctuations |
| Good Adhesion | Enhances bonding to various substrates in adhesive and coating formulations |
| High Purity (≥98%) | Ensures consistent polymerization and reliable end‑product performance |
| MEHQ Stabilized (≤200 ppm) | Provides excellent storage stability |
| Parameter | Specification |
|---|---|
| Chemical Name | Stearyl Methacrylate / Octadecyl Methacrylate |
| CAS No. | 32360‑05‑7 |
| Molecular Formula | C₂₂H₄₂O₂ |
| Molecular Weight | 338.57 g/mol |
| Appearance | White solid to light yellow liquid |
| Assay | ≥ 98% |
| Acid Value | ≤ 0.5 mg KOH/g |
| Inhibitor (MEHQ) | ≤ 200 ppm |
| Melting Point | ~18–20°C |
| Density | ~0.864 g/mL at 25°C |
| Flash Point | ~191°C |
SINOMER® SMA is a versatile monomer used across a wide range of industries:
Architectural & Industrial Coatings – Improves durability, water resistance, and corrosion protection
Release Coatings – Provides low‑surface‑energy release properties
High‑Performance Inks – Enhances flexibility and adhesion
Waterproof & Oil‑Proof Agents – Imparts durable water repellency to fabrics
Textile Finishing Auxiliaries – Improves softness and hand feel
Leather Auxiliaries – Enhances flexibility and water resistance
Pressure‑Sensitive Adhesives – Provides flexibility and tack balance
Structural Adhesives – Improves toughness and weatherability
Lubricating Oil Additives – Acts as pour point depressant and viscosity index improver
Crude Oil Viscosity Reducers – Reduces flow resistance in pipelines
Flow Inhibitors – Controls rheology in various formulations
Plastics & Floor Care Products – Enhances surface properties
The long C₁₈ alkyl chain significantly reduces surface energy, making coatings and films highly resistant to water, dirt, and stains. Surfaces stay cleaner longer and are easier to maintain.
SMA‑based polymers exhibit outstanding flexibility without sacrificing mechanical strength – ideal for applications requiring both durability and pliability.
The hydrophobic nature of the C₁₈ side chain provides excellent resistance to UV degradation, moisture ingress, and thermal cycling, extending service life in outdoor applications.
Low shrinkage ensures dimensional stability in cured films and molded parts. Low volatility contributes to safer, more environmentally friendly formulations.
SMA readily undergoes free‑radical polymerization, ATRP, RAFT, and radiation‑initiated polymerization, enabling incorporation into diverse polymer architectures – from linear homopolymers to complex copolymers and comb‑like structures.
Packaging: 25 kg / 200 kg drum
Storage: Keep in a dry, clean, well‑ventilated warehouse. Avoid exposure to light and heat. Protect from leakage, rain, and direct sunlight during transportation.
Shelf Life: 24 months in original unopened packaging under recommended storage conditions.
A: Both are long‑chain C₁₈ monomers, but SMA is a methacrylate (contains an α‑methyl group), while SA is an acrylate. The α‑methyl group in SMA provides better flexibility, lower shrinkage, and improved weather resistance compared to SA, which typically offers faster cure speed but higher shrinkage and less flexibility. SMA is preferred for applications requiring long‑term durability and dimensional stability.
A: Dosage varies by application. In coatings and inks, SMA is typically used at 5–30% of total monomer content. In adhesives, 10–40% is common. In specialty applications like oil additives, lower levels (1–10%) are typical. Optimal levels should be determined through formulation testing.
A: Yes. SMA polymerizes via free‑radical mechanisms and can be incorporated into UV‑curable formulations. Its low shrinkage and flexibility make it particularly attractive for UV coatings requiring good adhesion and weatherability.
A: 24 months when stored in original unopened packaging under recommended conditions (cool, dry, well‑ventilated, away from light and heat).
A: Yes, SINOMER® SMA is stabilized with MEHQ (monomethyl ether hydroquinone) at ≤200 ppm to prevent premature polymerization during storage.
A: SMA is hydrophobic and not water‑soluble. It is typically used in solvent‑borne, UV‑curable, and high‑solids systems. For waterborne applications, it can be incorporated via emulsion polymerization or as a co‑monomer in properly formulated dispersions.
A: Key markets include architectural and industrial coatings, textile finishes, leather auxiliaries, pressure‑sensitive adhesives, release coatings, lubricating oil additives, and crude oil flow improvers.
A: Use in well‑ventilated areas. Avoid skin and eye contact – wear appropriate protective gloves and goggles. In case of contact, wash thoroughly with soap and water. Consult the SDS for complete safety information.
Sinocure Chemical Group
No. 61, South Industrial Road, Jinan Area of Shandong Pilot Free Trade Zone, China
Email: Info@sinocurechem.com | Tel: +86 15668330235
Website: www.sinocurechem.com
This document is for informational purposes only. Users should conduct their own testing to determine suitability for their specific applications. SINOMER® is a registered trademark of Sinocure Chemical Group.
