Overview
This phthalate-free methyl ethyl ketone peroxide (MEKP) has moderate reactivity and low moisture content, and is used in conjunction with a cobalt accelerator for curing unsaturated polyester resin at room temperature or elevated temperature. This grade has a high content of methyl ethyl ketone peroxide monomer, which provides the resin with a short gel time. This page summarizes the published specifications for this grade and outlines what buyers should consider before sourcing it.
Specifications
| Appearance, 20-25°C | Transparent liquid |
| Total reactive oxygen species | 8.8-9.0% |
Characteristics
| Density, 20°C | 1.0 g/cm³ |
Applications of Butanox M-50A Across Market Segments
It is a versatile MEKP used for the curing of unsaturated polyester resin at room temperature along with a cobalt accelerator. It can also be used for thermal curing of unsaturated polyester resin under conditions of 100-127°C, giving fabricators flexibility between ambient and heat-cured processes. Its high content of methyl ethyl ketone peroxide monomer provides the resin with a short gel time, which is a relevant consideration for production schedules where cycle time matters.
Why the Phthalate-Free Formulation of Butanox M-50A Matters
Unlike standard MEKP grades that rely on phthalate plasticizers, this grade is formulated without phthalate plasticizers while maintaining moderate reactivity and low moisture content. This is relevant for fabricators facing regulatory or customer-driven restrictions on phthalate content in finished composite parts. The combination of low moisture content and phthalate-free formulation supports consistent decomposition behavior when paired with a cobalt accelerator, without introducing the plasticizer chemistry found in some conventional MEKP curing systems.
Why Sourcing Consistency Matters for Buyers
Because this product relies on a high content of methyl ethyl ketone peroxide monomer to deliver a short gel time, lot-to-lot consistency in total reactive oxygen species content is a direct driver of cure repeatability. A supplier that consistently delivers this grade within its stated 8.8-9.0% total reactive oxygen species range and 1.0 g/cm³ density reduces the need to re-tune cobalt accelerator loading with every new batch.
This is particularly relevant for fabricators running scheduled gelcoat or laminating production, where a batch outside specification can shift gel time and affect part quality. Reviewing the certificate of analysis for reactive oxygen content and density before a batch enters production is a reasonable quality check for this phthalate-free grade.
What to Consider When Sourcing Butanox M-50A
Buyers should confirm whether their process uses room-temperature curing with a cobalt accelerator or thermal curing in the 100-127°C range, since cycle time and accelerator dosing expectations differ between the two approaches. Requesting the current safety data sheet alongside the certificate of analysis helps confirm that a given batch matches the appearance and reactive oxygen specifications listed above before it is scheduled into production.
Because this grade is positioned as phthalate-free, buyers with regulatory or customer requirements around plasticizer content should confirm this formulation detail directly with the supplier as part of their qualification process. Packaging, storage temperature, and transport classification should also be confirmed given the regulatory requirements around organic peroxides.
General Handling and Storage Guidance
As with other organic peroxides, Butanox M-50A should be stored in accordance with the supplier’s safety data sheet, typically in a cool, dry, well-ventilated area away from direct sunlight, incompatible materials, and sources of heat or ignition. Personnel handling this product should follow the personal protective equipment and handling procedures specified in the SDS, since organic peroxides can decompose exothermically under certain storage or contamination conditions.
Buyers should request and review the current safety data sheet prior to receipt, and confirm that on-site storage conditions, including temperature control, are compatible with the recommended storage requirements. Proper inventory rotation and adherence to the stated shelf life help maintain the reactive oxygen content and gel-time performance described above.
Where to Source This Product
Chemicalsstore.com provides supply chain resource support for Butanox M-50A and related organic peroxide grades used in unsaturated polyester resin curing. Buyers can review our broader organic peroxide product range for related curing systems. For general reference on peroxide classification and safe handling practices, buyers can also consult resources such as the ASTM International standards library.
Documentation We Can Provide
For qualified buyers, we can provide the safety data sheet and, where available, a certificate of analysis for the specific batch of Butanox M-50A being quoted. Specifications listed on this page reflect the manufacturer’s published values; buyers should confirm current documentation before finalizing a purchase order.
FAQ
What is Butanox M-50A used for?
Butanox M-50A is used for curing unsaturated polyester resin at room temperature with a cobalt accelerator, and can also be used for thermal curing at 100-127°C.
Is Butanox M-50A phthalate-free?
Yes. Butanox M-50A is a methyl ethyl ketone peroxide formulated without phthalate plasticizers, with moderate reactivity and low moisture content.
What is the reactive oxygen content of Butanox M-50A?
Butanox M-50A has a published total reactive oxygen species content of 8.8-9.0%.
Does Butanox M-50A provide a short gel time?
Yes. Its high content of methyl ethyl ketone peroxide monomer provides the resin with a short gel time.
Get a Quote for Butanox M-50A
Contact our team for pricing, documentation, and lead time on Butanox M-50A. Our sourcing specialists can help confirm whether this phthalate-free MEKP matches your curing process before you place an order.
