tert-Butylphenyl diphenyl phosphate

tert-Butylphenyl diphenyl phosphate (CAS 56803-37-3), also known commercially as butylated triphenyl phosphate, is an organophosphate ester used as both a flame retardant and plasticizer in polymer systems.

It reduces flammability while simultaneously improving the flexibility and processability of rigid formulations. In electronics, it is incorporated into printed circuit board laminates and connector housings.

It is also used in encapsulant resins where UL 94 flame ratings are required alongside dimensional stability. Automotive interior components, including instrument panels and wire harness insulation, use it frequently.

Under-hood polymer parts use it to meet fire resistance standards without sacrificing mechanical performance. Aerospace and defense applications rely on it in high-performance polymer composites and coatings.

In these sectors, halogen-free flame retardancy is a qualification requirement. It also functions as a secondary plasticizer in rigid PVC and engineering thermoplastics, improving melt flow during processing.

tert-Butylphenyl diphenyl phosphate is supplied as a clear to pale yellow liquid. Technical grade is the standard commercial form, with purity specifications typically at 97% or above.

It is available in bulk liquid quantities and intermediate packaging such as drums and IBCs. This availability is consistent with industrial procurement volumes and large-scale manufacturing requirements.