Butanox M-50A

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Organic peroxide

Organic peroxide

Butanox M-50A: Phthalate-free, medium-reactive, general purpose MEKP with low water content for curing unsaturated polyester resins at room temperature.

  • Product name

    Butanox M-50A
  • Chemical family

    Organic peroxide
  • CAS number

  • Physical form

  • Regional availability

    Africa, Asia Pacific, Europe, India, Latin America, Middle East, North America
  • Chemical name

    Methyl ethyl ketone peroxide
  • Applications

    Butanox M-50A is a multipurpose catalyst for the room temperature cure of promoted unsaturated polyester resins. Unpromoted unsaturated polyester resins can be heat-cured with Butanox M-50A in the temperature range of 100-127°C. Butanox M-50A VR also has a high MEKP monomer content which may provide faster gel times in some resin systems.

Market Segments

Thermoset composites

Detailed description

The phthalate-free work horse in GRP curing systems. Medium-reactive, general purpose methyl ethyl ketone peroxide (MEKP) with guaranteed low water content, used for curing unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures.


  • Curing agent


  • Engineered Stone,
  • Gelcoats,
  • Buttons,
  • Coatings,
  • Resin Transfer Molding,
  • Filament winding,
  • Hand lay up and spray up