Trigonox® 121, tert-amyl peroxy-2-ethylhexanoate, is a perester which is used for the curing of unsaturated polyester resins at high temperatures.
Trigonox® 121 is preferred for the curing of UP resin based Hot Press Molding formulations (such as DMC and BMC) in the temperature range of 120-160°C as such or as a kicker in combination with a low reactive peroxide like e.g. Trigonox® C or Trigonox® 127. The low reactive peroxide must be included in the formulation in order to achieve a complete cure.
Trigonox® 121 as such is in comparison with Trigonox® 21, tert-butyl peroxy-2 ethylhexanoate, somewhat faster and will in general result in a more efficient cure and a lower residual styrene content of the molded part.
Trigonox® 121 has normally a much shorter pot life in the pure resin and is more reactive than Trigonox® C, tert-butyl peroxybenzoate.