Acrylic Acid: Properties, Handling & Lab FAQs

Acrylic acid is a reactive, light-yellow organic acid widely used in polymer synthesis, superabsorbent materials, and specialty chemical research, supplied by Aladdin Scientific at ≥98.0% purity (GC) with 180–220 ppm MEHQ as a polymerization inhibitor.

Purity

≥98.0% (GC)

Appearance

Light yellow liquid

Inhibitor

180–220 ppm MEHQ (4-methoxyphenol)

CAS Number

79-10-7

Molecular Formula

C₃H₄O₂

Molecular Weight

72.06 g/mol

SKU

A1523893

What Is Acrylic Acid and What Is It Used For?

Acrylic acid (CAS 79-10-7, molecular formula C₃H₄O₂, MW 72.06 g/mol) is the simplest unsaturated carboxylic acid. Its conjugated vinyl group makes it highly reactive toward free-radical, anionic, and coordination polymerization. In research laboratories, acrylic acid is used as a monomer for synthesizing polyacrylic acid, cross-linked superabsorbent polymers, hydrogels, and acrylic copolymers. It also serves as a reactive intermediate in organic synthesis and surface-modification chemistry. Industrial derivatives include acrylate esters, dispersants, flocculants, and coatings precursors.

Purity, Grade, and Inhibitor Specification

Aladdin Scientific's acrylic acid (SKU A1523893) is supplied at a purity of ≥98.0% as determined by gas chromatography (GC). The product appears as a light yellow liquid, which is normal for inhibited acrylic acid and does not indicate degradation.

The product contains 180–220 ppm MEHQ (4-methoxyphenol, monomethyl ether hydroquinone) as a polymerization inhibitor. MEHQ is an industry-standard radical scavenger added to prevent spontaneous polymerization during storage and shipping. The inhibitor requires dissolved oxygen to function effectively; therefore, the headspace of storage containers should not be purged with inert gas unless the inhibitor is first removed.

If inhibitor-free acrylic acid is required for a specific polymerization protocol, MEHQ can be removed by passing the acid through a column of inhibitor-removal resin or by vacuum distillation under a nitrogen blanket immediately before use. Researchers should verify residual inhibitor levels by GC or UV spectrophotometry after removal.

Storage, Stability, and Handling Precautions

Storage: Acrylic acid should be stored in a tightly sealed container in a cool, well-ventilated area away from heat sources, ignition sources, and oxidizing agents. Recommended storage temperature is 2–8 °C for long-term stability; short-term storage at room temperature is acceptable provided the container remains sealed. Avoid freezing, as acrylic acid solidifies near 14 °C and frozen material may crack glass containers.

Stability: Even in the presence of MEHQ, acrylic acid can polymerize exothermically if exposed to heat, light, peroxides, or strong acids/bases. Containers that have been opened should be resealed promptly and used within a reasonable period.

Personal protective equipment (PPE): Acrylic acid is corrosive and flammable (flash point approximately 54 °C, closed cup). Always handle in a fume hood. Wear chemical-resistant gloves (nitrile or neoprene), safety goggles, and a lab coat. In case of skin contact, wash immediately with copious water for at least 15 minutes.

Waste disposal: Dispose of acrylic acid waste in accordance with local regulations for flammable, corrosive organic liquids. Do not pour down the drain.

Quality Control and Analytical Methods

The purity specification of ≥98.0% is established by gas chromatography (GC), which quantifies acrylic acid content relative to identified impurities such as propionic acid, acetic acid, furfural, and polymerization by-products. MEHQ inhibitor concentration (180–220 ppm) is typically verified by UV spectrophotometry or HPLC.

For researchers requiring additional quality data, a Certificate of Analysis (CoA) is available for each lot. The CoA documents the specific GC purity result, MEHQ content, appearance, and any additional tested parameters for that production batch. Contact Aladdin Scientific customer service with the lot number to obtain the CoA.

Ordering, Availability, and Regulatory Information

Acrylic acid (SKU A1523893) is available through the Aladdin Scientific online store and authorized distributors. When placing an order, confirm the required pack size and verify that your institution has appropriate safety approvals for receiving flammable, corrosive liquids.

Shipping: As a flammable corrosive liquid, acrylic acid is classified as a hazardous material for transport (UN 2218). Shipments are subject to IATA (air) and ADR/IMDG (ground/sea) dangerous-goods regulations. Ground shipping within approved regions is the standard dispatch method. Contact Aladdin Scientific for specific regional shipping options and lead times.

Regulatory: Acrylic acid is listed in various national chemical inventories (e.g., TSCA, REACH). Users are responsible for verifying compliance with local import, handling, and use regulations. Safety Data Sheets (SDS) compliant with GHS are available for download from the product page.

Frequently asked questions

Why is Aladdin's acrylic acid light yellow rather than colorless?

The light yellow color is normal and expected. It results from the presence of 180–220 ppm MEHQ (4-methoxyphenol) inhibitor, which imparts a slight yellow tint. This appearance is within specification and does not indicate impurity or degradation of the product.

How do I remove the MEHQ inhibitor from acrylic acid before polymerization?

MEHQ can be removed by passing acrylic acid through a column packed with commercially available inhibitor-removal resin (e.g., activated alumina or specific scavenger resins) immediately before use. Alternatively, careful vacuum distillation under a nitrogen atmosphere is effective. Always verify inhibitor removal by GC or UV analysis, and use the inhibitor-free monomer promptly to avoid spontaneous polymerization.

What purity grade of acrylic acid is suitable for research synthesis?

Aladdin's acrylic acid at ≥98.0% purity (GC) is suitable for most research-scale polymer syntheses, hydrogel preparation, and organic synthesis applications. If your protocol requires higher purity or a specific impurity profile, please contact our technical support team and request the lot-specific Certificate of Analysis before ordering.

What are the key safety hazards of acrylic acid I should know before ordering?

Acrylic acid is flammable, corrosive, and capable of exothermic polymerization if mishandled. It causes burns to skin, eyes, and mucous membranes. It must be stored away from heat and ignition sources and handled exclusively in a fume hood with appropriate PPE (chemical-resistant gloves, goggles, lab coat). Review the GHS-compliant SDS available on the product page before use.

How should acrylic acid be stored to maximize its shelf life?

Store acrylic acid in its original tightly sealed container at 2–8 °C in a cool, dark, well-ventilated location, segregated from oxidizers, peroxides, and strong bases. Do not freeze (solidification point ~14 °C). Ensure the headspace contains air (oxygen is needed for MEHQ to function). Under these conditions, the inhibited product remains stable for the period stated on the label.

References

1. Sigma-Aldrich / Merck product documentation for acrylic acid, inhibited with MEHQ. Safety Data Sheet (GHS). Referenced for general physicochemical properties and inhibitor handling guidance.
2. NIST WebBook: Acrylic acid (CAS 79-10-7). National Institute of Standards and Technology. Physicochemical data including molecular weight and formula.
3. UN Recommendations on the Transport of Dangerous Goods: UN 2218, Acrylic acid, stabilized. Classification as flammable corrosive liquid.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.