MEKP-388VR is a general purpose methyl ethyl ketone peroxide (MEKP) with a VR system for the curing of unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures.

Specifications

Appearance	Red liquid
Total active oxygen	9.7-10.0 %

Characteristics

Density, 20 °C	1.120 g/cm³
Flashpoint	37 (Closed Cup) / ≥ 63 (Open Cup) °C

Applications

MEKP-388VR is general purpose methyl ethyl ketone peroxide (MEKP) for the curing of unsaturated polyester resins in the presence of a cobalt accelerator at room and elevated temperatures. The curing system MEKP-388VR/cobalt accelerator is developed for general purpose GRP- and non GRP-applications such as the curing of laminating resins and castings. For room temperature application it is necessary to use MEKP-388VR together with a cobalt accelerator (e.g. Accelerator™ NL-49PN). The vanishing red (VR) series of products include a red indicator system that disappears during the cure. The red color is only visible when needed but not in the finished end product. The key features are: indicates initiator presence, monitoring of the mixing step, monitoring of the cure by color and indicating under-cured area’s in the mold, and last but not least it leaves the end product colorless after the cure.

Thermalstability

Organic peroxides are thermally unstable substances, which may undergo self-accelerating decomposition. The lowest temperature at which self-accelerating decomposition of a substance in the original packaging may occur is the Self- Accelerating Decomposition Temperature (SADT). The SADT is determined on the basis of the Heat Accumulation Storage Test.

SADT	55°C
Method	The Heat Accumulation Storage Test is a recognized test method for the determination of the SADT of organic peroxides (see Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria – United Nations, New York and Geneva).

Storage

Due to the relatively unstable nature of organic peroxides a loss of quality can be detected over a period of time. To minimize the loss of quality, Thousands chemicals recommends a maximum storage temperature (Ts max.) for each organic peroxide product.

Ts Max.	25°C
Note	When stored under the recommended storage conditions, MEKP-388VR will remain within the Nouryon specifications for a period of at least 6 months after delivery.

Packaging and transport

The standard packaging is a 20 l HDPE can for 20 kg peroxide solution. Both packaging and transport meet the international regulations. For the availability of other packed quantities contact your Thousands chemicals’ representative. MEKP-388VR is classified as Organic peroxide type D; liquid; Division 5.2; UN 3105; PG II.

Safety and handling

Keep containers tightly closed. Store and handle MEKP-388VR in a dry well-ventilated place away from sources of heat or ignition and direct sunlight. Never weigh out in the storage room.Avoid contact with reducing agents (e.g. amines),acids, alkalis and heavy metal compounds (e.g. accelerators, driers and metal soaps). Please refer to the Safety Data Sheet (SDS) for further information on the safe storage, use and handling of MEKP-388VR. This information should be thoroughly reviewed prior to acceptance of this product.

Major decomposition products

Carbon dioxide, Water, Acetic acid, Formic acid, Propanoic acid, Methyl ethyl ketone.