Organic Peroxides in the Composites Sector

Organic Peroxides: Compounds containing -O-O- bonds. The -O-O bond is called the peroxide group. Chemical substances that can generate free radicals through chemical decomposition and are frequently used in polymerization reactions as initiators, cross-linking agents, catalysts, hardeners and accelerators in the composite and petrochemical sectors.

Composite Materials:

Created by combining materials from the same or different groups to bring together their best properties or to produce a new characteristic. Composite materials, which are developing rapidly, have entered almost every aspect of our lives today. For this reason, Akpa Kimya continues its development with the slogan "A Little Akpa Wherever You Touch" by taking into account the products it manufactures. Organic peroxide products used in the composite sector are used worldwide in many fields such as jar lids, buttons, kitchen countertops, automotive spare parts, bathtub and tank manufacturing. The most well-known group of organic peroxides performing the hardener function is ketone peroxides; they generally operate at ambient temperature. Ketone peroxides, which have many combinations, when combined with resin formulations due to their different properties, can demonstrate working capacity in the properties desired by each user. In cold processes (at ambient temperature), cobalt salts and organic amines are used as accelerators together with organic peroxides, while in hot processes the organic peroxide is activated by temperature.

Methyl Ethyl Ketone Peroxides (MEKP)

Methyl ethyl ketone raw material, hydrogen peroxide affecting the gel, the monomer form of MEKP which affects the gel to a small degree but greatly improves it, the dimer form of MEKP which has little effect on the gel but significant effect on cure, and dimethyl phthalate, diisobutyl phthalate or solvents such as TXIB, IRIS used to make MEKP safe are created through their combinations. By changing the ratio of each of these components, the gel and cure times of a resin can be altered. Solvents are of two types: phthalate and phthalate-free. Efforts are being made worldwide to reduce the use of phthalates (because they are carcinogenic), and therefore work continues on the development of phthalate-free products. As Akpa Kimya, we manufacture and supply our customers with many types of MEKP group products including phthalate products such as Akperox A60/A50, Akperox A1 and phthalate-free products such as Akperox A60PF/A50PF, Akperox A6R/A5R.

Acetylacetone Peroxides (AAP)

Unlike methyl ethyl ketone peroxides, the active content of acetylacetone peroxide cannot be changed. Since there is fundamentally only one active molecule, determining and using the correct amount of AAP correctly is extremely important. Compared to MEKP products, it is a very effective polymerization initiator for curing unsaturated polyester resins at room temperature and provides rapid cures without significantly affecting gel times in most resin systems. It is generally suitable for other applications such as resin transfer molding (RTM) and cast polymers due to the rapid demolding time. As Akpa Kimya, our Akperox AAP product is manufactured for this group.

Methyl Isobutyl Ketone Peroxides

They are good oxidizing agents. They are generally preferred in hot processes to provide rapid gel-cure. Suitable for applications such as benches, roof coatings, continuous lamination. Akpa Kimya's Akperox MIKP/MIKP-S product is included in this range.

MEKP/AAP Mixtures:

While both organic peroxides have positive properties when used individually, the use of a combination of the two products has also become popular in recent times. Can be used in both cold and hot processes. The advantages are minimizing the disadvantages of both peroxides and being able to better control gel and cure times. Akperox ER33/ E34/ER37/ER73 products are manufactured specifically for these processes.

Hydroperoxides

Tert-Butyl Hydroperoxides (TBHP) are used as initiators in composite curing, vinyl polymerization and cross-linking within polymers and in emulsion polymerization of styrene, acrylates and methacrylates. They also serve as oxidizing agents for hydrocarbons. Akperox TBHP70 products are manufactured specifically for these processes.

Cumyl Hydroperoxides (CHP) and MEKP/CHP Mixtures

Particularly suitable for initiating cure of resin systems at both ambient and elevated temperatures. Having a longer gel time compared to MEKP, it minimizes possible cracking within the resin. (Examples of the Cumyl Hydroperoxide group are Akperox C90/C80/C50/C45 and examples of MEKP/CHP mixture products are Akperox CMP50/CMP75.) Diacyl Peroxides Have wide application areas. In addition to unsaturated polyester and cure applications, cross-linking of elastomers, PVC production, and use in polystyrene and polyacrylates are suitable. Dibenzoyl Peroxide (BPO), one of these peroxides, is used with unsaturated polyesters and acrylic monomers at room temperature. BPO powder (granule) forms are preferred for use as catalysts in road marking paints, in EPS (expanded polystyrene) applications, in the manufacture of foams used for heat insulation, and in cosmetics (acne treatment), while BPO paste forms or liquid suspensions can be used as hardeners in marble adhesives and putties in car carports. (Examples of the BPO powder group are Akperox BP75/BP50 Powder, examples of BPO Paste group products are Akperox BP50 Paste in white, red and blue colors, and Akperox BP15/BP17/BP20 Paste products in black and gray colors). Simge Arık / R&D Responsible - Akpa