Toluene (Technical Grade)
CAS 108-88-3Toluene (methylbenzene, CAS 108-88-3) is an aromatic hydrocarbon solvent with strong solvency for a wide range of resins, rubber, and polymer systems.
Key Features
- ✓High aromatic solvency — dissolves rubbers, bituminous materials, and aromatic resins
- ✓Moderate evaporation — appropriate for contact adhesives and primer formulations
- ✓Reproductive toxicant (EU Category 2) — requires strict exposure control
- ✓Often replaced by xylene in coating applications for lower neurotoxicity profile
- ✓Class IB flammable (flash point 4°C) — requires NFPA 30 compliant storage
Specifications
| Parameter | Value |
|---|---|
| Purity | ≥99.5% by GC |
| Appearance | Clear, colorless liquid with aromatic odor |
| CAS Number | 108-88-3 |
| Flash point | 4°C (ASTM D93) |
| Boiling point | 111°C |
| Density (20°C) | 0.867 g/cm³ |
| Relative evaporation rate | ~2.0 (n-BuAc = 1.0) |
FAQ
Toluene and xylene have similar aromatic solvency characteristics and are sometimes interchangeable in coating formulations, but there are important differences: (1) Evaporation rate: toluene evaporates about 2x faster than xylene, which can affect drying time, open time, and film formation in coatings; (2) Boiling point: toluene bp 111°C vs. xylene bp 138–144°C — this affects viscosity reduction efficiency at different temperatures; (3) Health profile: xylene is generally considered less neurotoxic than toluene, though both are hazardous; (4) Formulation compatibility: some formulations are specifically designed for one aromatic solvent — substitution may require rebalancing the solvent blend ratio. In most rubber-based adhesive and chlorinated rubber primer applications, toluene and xylene can be substituted at 1:1 ratio with minor formulation adjustment for evaporation rate.