tert-Butyl Hydroperoxide (TBHP, CAS 75-91-2) is a water-soluble organic hydroperoxide widely used as a polymerisation initiator, an oxidant, and a component of redox curing systems for unsaturated polyester / vinyl ester resins. This guide summarises properties, half-life, applications and safety.
Identity
- Chemical name: tert-butyl hydroperoxide
- CAS: 75-91-2; Formula: C₄H₁₀O₂; MW: 90.12
- Theoretical active oxygen: ~17.8% (100% basis)
- Common forms: ~70% aqueous solution (TBHP-70 / TBHP-70-AQ), some solvent grades
Half-life & activation
TBHP decomposes at high temperature (10-hour half-life temperature typically above ~160 °C, varying with concentration and medium); purely thermal initiation needs high temperature. Industrially it is usually activated at lower temperature via a redox system with cobalt or other transition metals, or used for high-temperature emulsion/solution polymerisation. Confirm values against the supplier TDS/SDS.
Applications
- UP / vinyl ester resin redox curing: with a cobalt promoter, enabling lower-temperature cure.
- Polymerisation initiator: emulsion/solution polymerisation of styrene, acrylates.
- Oxidant: epoxidation and oxidation syntheses in fine chemicals.
Forms & selection
The 70% aqueous solution meters easily and suits water-based/emulsion systems; solvent grades suit water-sensitive or organic-compatible systems. Common equivalents include Luperox TBH70X and Trigonox A-W70.
Safety & storage
- Organic hydroperoxide: strongly oxidising and corrosive; avoid contact with reducing agents, metal powders, strong acids/bases and promoters.
- Store cool and ventilated (typically ≤ 30 °C), away from heat and contamination; follow the SDS SADT and stacking limits and keep containers vented.
- Keep separate from cobalt/amine promoters; meter separately.
Selection
Choose TBHP for high-temperature thermal initiation or low-temperature redox cure; BPO for 60–90 °C medium-temperature cure; TBPB/TBPEH/DCP for >120 °C. See the half-life chart and the BPO guide.
Note: half-life values are typical references; confirm against the current TDS/SDS and trials.