United Initiators CUROX®M-503 Methyl ethyl ketone peroxide 1338-23-4

Product Description.

• CUROX® M-503 is a colorless liquid consisting of a peroxide based on methyl ethyl ketone, desensitized by a phthalate plasticizer.
• It is used as a source of free radicals to initiate unsaturated polyester resins.
• Main applications: handcrafting, spraying, continuous lamination, centrifugal casting, fiber winding and polyester concrete.

Technical data.

• Appearance: colorless liquid
• Active Oxygen Content: Approx. 9.5% w/w
• Free hydrogen peroxide content: approx. 3.5% w/w
• Water content: approx. 5.0% w/w
• Desensitizer: Dimethyl phthalate
• Density at 20°C: approx. 1.12 g/cm³.
• Viscosity at 20°C: approx. 20 mPa-s
• Solubility: Soluble with alcohols, phthalates

Applications.

• Primary use is with cobalt catalysts for curing all unsaturated polyester resin types at room temperature.
• Standard dosage levels: 1-31 TP3T as supplied, 0.5-21 TP3T with 11 TP3T cobalt solution.
• Compared to standard MEKP, the "pot time" (gel time of resin + peroxide + catalyst) is shorter, but can be extended by adding Inhibitor TC-510.
• Higher heat generation rate. Relatively short demolding times. Curing times are significantly longer at temperatures below 20°C, when a cobalt/amine catalyst should be used.