Bis(tert-butylperoxyisopropyl)benzene (CAS 25155-25-3), also known as BIPB or "Odorless DCP", is a premium organic peroxide widely used as a crosslinking agent in polymer industries. Its molecular formula is C₂₀H₃₄O₄ (MW: 338.48 g/mol) with a theoretical active oxygen content of 9.45%
Key Properties
Physical State: White crystalline powder or flakes
Melting Point: 44–48°C; Density: 1.63 g/cm³
Solubility: Insoluble in water; soluble in ethanol, benzene, and CCl₄
Decomposition: Half-life of 1 hour at 134°C, generating non-odorous byproducts (e.g., tert-butanol, acetone)
Applications
Rubber & Elastomer Curing:
Superior alternative to DCP (Dicumyl Peroxide) for EPDM, silicone rubber, and NBR, requiring only 2/3 the dosage for equivalent crosslinking efficiency
Eliminates unpleasant odors (common with DCP) in finished products like seals, cables, and foamed EVA
Polymer Modification:
Controls molecular weight distribution in polypropylene (PP) degradation for high melt-flow index resins
Initiator for styrene polymerization, yielding higher molecular weight PS
Safety & Handling
UN 3106, Class 5.2 Organic Peroxide (Packing Group II)
SADT (Self-Accelerating Decomposition Temperature): 80°C; store below 30°C away from combustibles
GHS Hazards: H242 (Heating may cause fire), H319 (Causes eye irritation)