Initiator Peroxides and Colorless Cobalt

Akpa Kimya's product portfolio includes the Akperox ER product group; methyl ethyl ketone peroxide/acetone acetone peroxide mixture products and acetone acetone peroxide/tert butyl peroxy benzoate mixture products. Methyl ethyl ketone peroxides and acetone acetone peroxides, when used individually, are combined in mixture peroxides to combine their effects and minimize the disadvantages present in both product groups. Akperox ER11, ER33, ER34, ER37, ER73 are methyl ethyl ketone peroxide and acetone acetone peroxide mixture products. Akperox ER59 and ER60 FW are acetone acetone peroxide and tert butyl peroxy benzoate mixture products. The only difference of ER11 from other products is that it is phthalate-free. The products are used with cobalt accelerators to cure unsaturated polyester resins at both elevated and ambient temperatures. Areas of application are particularly suitable for continuous production applications such as pipe production, continuous lamination, centrifugal casting, RTM (resin transfer molding), and filament winding. They are preferred for better control of desired gel and cure times during production. The MEKP/AAP mixture product plus cobalt combination provides faster cure and higher peak temperature when compared to the MEKP plus cobalt combination. Akperox PK295 D50; 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 50% The product in the cycloaliphatic perketal group is used as an initiator (radical source) in the curing of unsaturated polyester resins. It is particularly preferred in SMC and BMC hot press applications. Depending on the application, it operates in the range of 120-170°C.

Akcobalt RC88;

Curing of unsaturated polyester resins is not provided by organic peroxides alone. An accelerator must also be added. Accelerators are chemical substances that activate the peroxide. Cobalt metal is an accelerator used for ketone peroxide-based cure systems. The disadvantage of cobalt used in the curing process of unsaturated polyester resins is that it imparts its own color to the product, especially in transparent applications. For this reason, Akpa Kimya has developed and begun production of a colorless cobalt product under the name Akcobalt RC88. The product is particularly preferred for transparent applications. The images show applications prepared in laboratory conditions with resin plus initiator plus cobalt. In the application using standard cobalt, cobalt imparts its color to the resin, while in the application using Akcobalt RC88, transparency is observed.     Simge Arık Research and Development Specialist Akpa Kimya