Styrene Monomer, Vinyl Benzene, Ethenylbenzene, Phenylethylene, Styrol, Monostyrene Stabilized, 100-42-5

STYRENE MONOMER (SM)

Styrene / Vinyl Benzene / Ethenylbenzene / Phenylethylene / Styrol
CAS Number: 100-42-5
EC Number: 202-851-5

SECTION 1: PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

Styrene is a colorless to slightly yellowish, flammable liquid with a characteristic sweetish odor. It is a reactive monomer that polymerizes easily and is one of the most widely used thermoplastic raw materials in the world. It is primarily used in the production of polystyrene (PS), ABS, SBR rubber, and unsaturated polyester resins (UPR).

SECTION 2: SYNONYMS AND OTHER NAMES

SECTION 3: CHEMICAL STRUCTURE

3.1. Molecular Structure

Styrene consists of a benzene ring substituted with a vinyl group (-CH=CH₂). The vinyl group provides the reactive double bond that allows polymerization.

Structural Formula:

        CH=CH₂
         |
         C
        / \
       /   \
      /     \
     /       \
    C         C
    |         |
    C - H     C - H
    |         |
    C         C
     \       /
      \     /
       \   /
        \ /
         C

Simplified Representation:

        CH=CH₂
         |
    C₆H₅ - H

3.2. Molecular Formula

C₈H₈

3.3. Molecular Weight

104.15 g/mol

3.4. Key Structural Features

SECTION 4: PHYSICAL AND CHEMICAL PROPERTIES

SECTION 5: POLYMER AND MATERIAL PROPERTIES (Post-Application)

When styrene monomer is polymerized, it imparts the following characteristic properties:

SECTION 6: APPLICATIONS AND INDUSTRIAL USES

6.1. Plastics and Polymers

6.2. Automotive Industry

6.3. White Goods (Appliances)

6.4. Consumer Products

6.5. Construction and Infrastructure

6.6. Composite Industry (Fiber-Reinforced Plastics)

SECTION 7: PRODUCTION METHOD

Styrene is produced via petrochemical processes. The most common industrial method is the dehydrogenation of ethylbenzene.

Reaction Equation:
C₆H₅CH₂CH₃ (Ethylbenzene) → C₆H₅CH=CH₂ (Styrene) + H₂

SECTION 8: INHIBITOR AND STABILITY

SECTION 9: SECTORAL APPLICATION PATTERNS

9.1. Composite Industry (FRP – Fiber-Reinforced Polyester)

In this sector, styrene serves as a reactive diluent (solvent) . It thins the unsaturated polyester resin and becomes part of the polymer structure during curing.

Application Methods: Hand Lay-up, Filament Winding, Spray-up (Chopper Gun), Resin Transfer Molding (RTM).

Example Recipe (Hand Lay-up - 100 kg Resin Mixture):

9.2. Expanded Polystyrene (EPS - Styrofoam) Production

Styrene monomer is polymerized into beads, then impregnated with pentane gas. During application, steam heat expands the beads.

Note: This process occurs at the polymer (PS) stage, not the monomer stage.

9.3. SBR Rubber (Tire Industry)

Styrene is copolymerized with butadiene to produce synthetic rubber.

Recipe Note (Cold Emulsion Polymerization): Styrene (~23.5%) + Butadiene (~76.5%). This ratio determines tire traction and wear resistance.

SECTION 10: FORMULATION CONSIDERATIONS

SECTION 11: CRITICAL PROCESSING DEFECTS AND SOLUTIONS

SECTION 12: SAFETY AND HEALTH HAZARDS

12.1. Health Effects

12.2. Occupational Exposure Limits

Warning: If the sweetish odor becomes noticeably unpleasant, the exposure limit has been exceeded.

SECTION 13: GHS CLASSIFICATION

Signal Word: WARNING

Hazard Pictograms: GHS02 (Flame), GHS07 (Exclamation Mark), GHS08 (Health)

Hazard Statements (H-Codes):

SECTION 14: PRECAUTIONARY STATEMENTS (P-CODES)

SECTION 15: FIRST AID MEASURES

SECTION 16: FIRE-FIGHTING MEASURES

SECTION 17: ACCIDENTAL RELEASE MEASURES

SECTION 18: STORAGE AND SHELF LIFE

SECTION 19: PACKAGING OPTIONS

SECTION 20: TRANSPORT INFORMATION

SECTION 21: ENVIRONMENTAL INFORMATION

SECTION 22: REGULATORY INFORMATION

SECTION 23: ALTERNATIVE PRODUCTS AND COMPARISONS

Why is styrene still used? The cost-performance ratio is unmatched. Using MMA would double the cost of manufacturing a boat or truck body.

When to switch to alternatives? In closed-space applications (sewer pipe lining), cosmetic packaging, medical devices, or where human contact is intense and odor tolerance is low, switching to vinyl toluene or DCPD-based resins is necessary.

SECTION 24: OTHER NAMES AND SYNONYMS

SECTION 25: QUICK REFERENCE TABLE

SECTION 26: CRITICAL NOTICES AND BEST PRACTICES

CRITICAL NOTICES:

1. Polymerization Risk: Styrene spontaneously polymerizes, especially at elevated temperatures. The inhibitor (TBC) requires oxygen to function. Store with a nitrogen blanket in tightly closed containers. Avoid oxygen depletion.

2. Vapor Accumulation: Styrene vapor is 3.6 times heavier than air and accumulates at ground level, forming an invisible gas layer. Exhaust fans should be positioned at floor level, not ceiling level, in composite workshops.

3. Flammability: Styrene is flammable (flash point 31°C). Vapors can form explosive mixtures with air. Keep away from heat, sparks, and open flames. Ground all equipment.

4. Carcinogenicity: IARC classifies styrene as Group 2B (possibly carcinogenic to humans). Use adequate ventilation and personal protective equipment.

5. MEKP Reaction: Never pour peroxide hardener (MEKP) directly onto cobalt accelerator. This causes immediate fire or explosion. Always mix accelerator thoroughly into the resin first, then add peroxide.

6. Kokulu ve Sağlık: The odor threshold is 0.1 ppm. If the sweetish odor becomes noticeably unpleasant, the exposure limit (20 ppm TWA) has been exceeded. Activated carbon filter masks are essential.

7. Excessive Styrene: Adding more than 5% additional styrene to resin reduces mechanical strength and causes surface micro-cracks (blooming).

8. Surface Tack: If the surface remains tacky, add 0.5% styrene-paraffin solution to the final coat. The paraffin migrates to the surface, trapping styrene and allowing proper curing.

BEST PRACTICE RECOMMENDATIONS:

• Storage: Store in a cool (<25°C), well-ventilated area. Keep containers tightly closed with nitrogen blanket. Use appropriate inhibitor (TBC). Monitor temperature and inhibitor levels.

• Handling: Use explosion-proof equipment. Ground all containers. Use respiratory protection (activated carbon filter). Use chemical-resistant gloves, goggles, and protective clothing.

• Ventilation: Install exhaust fans at floor level (vapor is heavier than air). Provide adequate general ventilation.

• Formulation: Do not exceed 5% additional styrene in resin. Use thixotropic agents or pre-heating to control viscosity.

• Curing: Follow correct sequence: resin + accelerator (mix) → hardener (mix) → apply. Never mix hardener directly with accelerator.

• Waste Management: Dispose of styrene and contaminated materials as hazardous waste. Do not pour down drains.

LEGAL DISCLAIMER:

This Technical Data Sheet (TDS) is for informational purposes only and is prepared based on available technical data. The user is solely responsible for determining the suitability of the product for their specific application and for complying with all local, national, and international regulations. For complete safety, storage, handling, transport, waste, and regulatory compliance information, the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier must be consulted. Styrene is a flammable and potentially hazardous substance and should be handled with extreme caution. This document does not substitute professional or medical advice.