alpha-methylstyrene

CAS: 98-83-9

Overview

Alpha-methylstyrene (CAS 98-83-9 ), commonly abbreviated as AMS, is a reactive monomer and co-monomer used across polymer chemistry and specialty chemical manufacturing.

Isopropenyl benzene is a recognized alternative name in some technical contexts. AMS primarily functions as a building block in resin synthesis and as a chain-transfer agent or modifier.

In coatings and adhesives, AMS is incorporated into styrene-acrylic and alkyd resin formulations to improve hardness, heat resistance, and film build for industrial applications.

Polymer manufacturers use it as a co-monomer in AMS-modified resins for packaging materials and printing inks, where controlled molecular weight is a production requirement.

In elastomer and sealant compounding, AMS-based resins serve as tackifiers and performance modifiers. At trace levels, AMS is also approved as a flavoring agent under FEMA guidelines.

These applications extend into food-contact and fragrance formulations. Alpha-methylstyrene is supplied as a clear liquid in bulk, ISO tank, and drum quantities for global distribution.

Technical grade is the standard commercial form, with inhibited grades available to prevent premature polymerization during storage and transport to ensure product stability.

Purity specifications typically range from 99% to 99.5%+ depending on end-use requirements. Our material meets rigorous industrial benchmarks for consistency and performance.

Physical Properties

Melting Point	-23.2 °C
Boiling Point	165.4 °C
Density	0.9106 g/cm³
Flash Point	114 °F
Appearance	Methylstyrene is a colorless liquid with a characteristic odor.
Color	Clear colorless
Form	Liquid
Water Solubility	insoluble
Vapor Pressure	2.1 mm Hg ( 20 °C)
Refractive Index	n 20/D 1.539
pH	5-6 (500g/l, H2O)
Log P	3.48 at 25℃

Safety & Handling

Warning GHS02 GHS07 GHS09 GHS05 GHS08 Hazard Statements H226 Flammable liquid and vapor H303 May be harmful if swallowed H304 May be fatal if swallowed and enters airways H315 Causes skin irritation H318 Causes serious eye damage H319 Causes serious eye irritation H320 Causes eye irritation H335 May cause respiratory irritation H336 May cause drowsiness or dizziness H341 Suspected of causing genetic defects H351 Suspected of causing cancer H361 Suspected of damaging fertility or the unborn child H371 May cause damage to organs H372 Causes damage to organs through prolonged or repeated exposure H373 May causes damage to organs through prolonged or repeated exposure H401 Toxic to aquatic life H411 Toxic to aquatic life with long lasting effects Precautionary Statements P203 Obtain, consult and follow expert instructions for use. P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking. P233 Keep container tightly closed. P240 Ground and bond container and receiving equipment. P241 Use explosion-proof [electrical/ventilating/lighting/…] equipment. P242 Use non-sparking tools. P243 Take action to prevent static discharges. P260 Do not breathe dust/fume/gas/mist/vapours/spray. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. 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. P273 Avoid release to the environment. P280 Wear protective gloves/protective clothing/eye protection/face protection. P317 Get emergency medical help. P318 IF exposed or concerned, get medical advice. P319 Get medical advice/attention if you feel unwell. P321 Specific treatment (see … on this label). P331 Do NOT induce vomiting. P391 Collect spillage. P405 Store locked up. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P301+P316 Get emergency medical help immediately. 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. P308+P316 Get emergency medical help immediately. P332+P317 Get emergency medical help. P337+P317 If eye irritation persists: Get medical advice/attention. Get emergency medical help. P362+P364 Take off contaminated clothing and wash it before reuse. P370+P378 Use … for extinction. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P403+P235 Store in a well-ventilated place. Keep cool. P303+P361+P353 IF ON SKIN (or hair): 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

HS Code	29029090
UN Number	2303
ADR Class	3
Packing Group	III
Storage Class	3 - Flammable liquids
WGK (Germany)	2

Other Names

Industries

Printing & Packaging Coatings, Adhesives, Sealants & Elastomers Personal Care & Cosmetics Plastics & Polymers