• Methyl ethyl ketone peroxide (MEKP) is an organic peroxide with the formula [(CH3)(C2H5)C(O2H)]2O2. It is a colorless oily liquid. It is widely used in vulcanization (crosslinking) of polymers.
• Solutions of 30 to 50% MEKP are used in industry as catalyst to initiate the crosslinking of unsaturated polyester resins used in fiberglass, and casting.
• For this application, MEKP often is dissolved in a phlegmatizer such as dimethyl phthalate, cyclohexane peroxide or diallyl phthalate to reduce sensitivity to shock.