Crotonic acid

CAS: 3724-65-0

Overview

Crotonic acid (CAS 3724-65-0 ), also known as beta-methylacrylic acid, is an unsaturated monocarboxylic acid used primarily as a reactive monomer and chemical intermediate across polymer and specialty chemical manufacturing.

Its conjugated double bond makes it a functional building block for synthesizing resins, coatings, and copolymers with targeted performance characteristics. In polymer chemistry, it is copolymerized with vinyl acetate.

This process produces hair-fixative resins used in aerosol sprays and styling formulations. Agricultural chemical manufacturers use it as an intermediate in synthesizing crop protection actives and adjuvant systems.

In food and flavor applications, it functions as a flavoring agent and acidulant in approved formulations, particularly where a mild acidity profile is required for specific end products.

Pharmaceutical producers also source it as a synthetic intermediate for active pharmaceutical ingredient (API) manufacturing. It is supplied as a white to off-white crystalline solid for industrial use.

Standard commercial grades include technical and pharmaceutical-grade material, with purity levels typically ranging from 99% upward for high-specification applications. Packaging is available in small drums through to bulk quantities.

Physical Properties

Melting Point	72 °C
Boiling Point	185 °C
Density	1.018 g/cm³ @ Temp: 15 °C
Flash Point	190 °F
Appearance	Crotonic acid is a white or colorless, crystalline solid with a pungent odor. May be transported as a molten liquid.
Odor	at 0.10 % in propylene glycol. roasted burnt
Water Solubility	soluble
Vapor Pressure	0.19 mm Hg ( 20 °C)
Refractive Index	1.4210 (estimate)
Log P	0.720

Safety & Handling

Danger GHS05 GHS07 GHS06 Hazard Statements H302 Harmful if swallowed H311 Toxic in contact with skin H312 Harmful in contact with skin H314 Causes severe skin burns and eye damage H315 Causes skin irritation H318 Causes serious eye damage H319 Causes serious eye irritation H335 May cause respiratory irritation Precautionary Statements P260 Do not breathe dust/fume/gas/mist/vapours/spray. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P262 Do not get in eyes, on skin, or on clothing. P264 Wash … thoroughly after handling. P270 Do not eat, drink or smoke when using this product. P271 Use only outdoors or in a well-ventilated area. P280 Wear protective gloves/protective clothing/eye protection/face protection. P316 Get emergency medical help immediately. P317 Get emergency medical help. P319 Get medical advice/attention if you feel unwell. P321 Specific treatment (see … on this label). P330 Rinse mouth. P363 Wash contaminated clothing before reuse. P405 Store locked up. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P301+P317 Get emergency medical help. P302+P352 IF ON SKIN: Wash with plenty of water. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P332+P317 Get emergency medical help. P337+P317 If eye irritation persists: Get medical advice/attention. Get emergency medical help. P361+P364 Take off immediately all contaminated clothing and wash it before reuse. P362+P364 Take off contaminated clothing and wash it before reuse. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P301+P330+P331 Rinse mouth. Do NOT induce vomiting. P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P305+P354+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

UN Number	2823
ADR Class	8
Packing Group	III
Storage Class	8A - Combustible corrosive hazardous materials
WGK (Germany)	3

Other Names

Industries

Pharmaceuticals & Healthcare Agriculture & Feed Plastics & Polymers Food & Nutrition