Styrene (CAS 100-42-5): Monomer Chemistry, Polymer Applications, and Stabilization Essentials
Styrene is one of the world’s top-volume commodity monomers — the hydrophobic aromatic backbone of polystyrene packaging, ABS engineering resin, SBR elastomers, and unsaturated polyester vinyl crosslinking. For buyers the technical conversation centers less on availability and more on inhibitor level, purity class, and cold-chain logistics, since unstabilized styrene polymerizes spontaneously at ambient temperature.
Chemical Identity and Key Properties
| Property | Value |
|---|---|
| CAS Number | 100-42-5 |
| Molecular Formula | C8H8 |
| Molecular Weight | 104.06 g/mol |
| Density | 0.906 at 68 °F (USCG, 1999) - Less dense than water; will float |
| Solubility | less than 1 mg/mL at 66 °F (NTP, 1992) |
Polymerization Chemistry
Free-radical polymerization of the vinyl group proceeds without initiator at elevated temperature but is normally initiated or controlled for molecular-weight design. The aromatic ring imparts rigidity, hydrophobicity, and optical clarity to derived polymers; copolymerization with acrylonitrile, butadiene, or maleic anhydride tunes toughness and heat resistance.
Material Families
Polystyrene
Crystal and high-impact PS serve packaging, disposables, and insulation (as expanded PS).
ABS/SAN Engineering Resins
Styrene-acrylonitrile and terpolymer ABS balance rigidity and impact for appliance, electronics, and automotive components.
Elastomers and Latex
SBR and styrene-butadiene latex support tires, paper coating, and carpet backing; styrene-isoprene block copolymers deliver thermoplastic elastomer behavior.
Unsaturated Polyester Crosslinker
As the reactive diluent in UP resins, styrene reduces viscosity and co-crosslinks with fumarate/maleate units during composite cure.
Inhibitors, Storage, and Safety
Commercial styrene ships with 10–15 ppm TBC (4-tert-butylcatechol); dissolved oxygen is required for TBC to function. Storage below 20 °C, limited headspace, and inventory rotation suppress polymer buildup. Styrene is a suspected carcinogen with flammable-vapor hazards — ventilation, bonding/grounding, and appropriate PPE are standard.
Frequently Asked Questions
What inhibitor level should I specify?
10–15 ppm TBC for general use; lower or higher levels are process-specific (some polymerizations require de-inhibition immediately before use).
How is styrene stabilized during shipping?
Under TBC with air headspace in suitable containers; cold storage extends shelf life — verify the inhibitor and dissolved oxygen are adequate on receipt.
Does CoreyChem supply styrene for specialty use?
Styrene and substituted styrene monomers can be supplied in laboratory quantities with COA documentation; bulk commodity volumes should be sourced through petrochemical channels.
Source from CoreyChem
CoreyChem supplies Styrene (CAS 100-42-5) with lot-specific COA and MSDS documentation. Custom synthesis, higher purity grades, and bulk packaging are available on request — contact our technical team with your target specification and quantity for current lead time and pricing.