Chlorendic anhydride

Chlorendic anhydride (CAS 115-27-5), also known as HET anhydride, is a halogenated cyclic anhydride used as a reactive flame retardant and curing agent in polymer systems.

Where is Chlorendic anhydride used?

• Epoxy resin formulations for electrical laminates and printed circuit boards: hardener that simultaneously imparts flame retardancy, reducing the need for separate additive packages
• Unsaturated polyester resins for construction panels, ducting, and marine components: meets fire performance standards required in building and transportation applications
• Aerospace and defense composites: specified where structural parts must satisfy stringent self-extinguishing or low flame-spread requirements for critical safety components
• Alkyd resin synthesis: halogen-based fire resistance built into the resin rather than applied as a coating, ensuring long-term material stability
• Unlike additive flame retardants, it chemically incorporates into the polymer backbone, delivering durable fire resistance without migration or leaching during the product lifecycle.

Good to know: Unlike additive flame retardants, it chemically incorporates into the polymer backbone, delivering durable fire resistance without migration or leaching during the product lifecycle.

Commercial specifications

• Technical grade, purity typically 98% or higher
• Packaging in fiber drums or multi-wall bags suited for bulk industrial procurement
• Store in a cool, dry environment to maintain chemical integrity