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4-Phenylethynylphthalic anhydride (PEPA)

CAS Number 119389-05-8

Chemistry Building Blocks, Heterocyclic Building Blocks, Monomers


Product Code B2151-LT-10g
Price $138 ex. VAT

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A phthalic anhydride intermediate

For the synthesis of polyimides as end-capping reagent in application of gas separation membranes and high-performance polymers


4-Phenylethynylphthalic anhydride (PEPA), CAS number 119389-05-8, a phthalic anhydride derivative, has a phenylethynyl substituent at 4-position. 4-Phenylethynylphthalic anhydride is commonly used as an end-capping reagent for polyimides synthesis and modification, such as TriA-X polyimides. The diphenylacetylene end-capping moiety undergoes thermally induced radical curing process for crosslinked polyimides. The crosslink further improves the thermal stability of the polyimides (5% decomposition temperature Td5 = 591.3 °C). Diphenylacetylene also reacts with tetraphenylcyclopentadienone forming a fully conjugated hexaphenylbenzene under Diels-Alder reaction.

PEPA can also be introduced as an imide pedant onto a polymer backbone that has free amines. The modified polymer membranes show improved gas permeability in application of gas separation.

General Information

CAS Number 119389-05-8
Chemical Formula C16H8O3
Full Name 4-Phenylethynylphthalic anhydride
Molecular Weight 248.23 g/mol
Synonyms 5-(Phenylethynyl)isobenzofuran-1,3-dione, 5-(Phenylethynyl)-2-benzofuran-1,3-dione
Classification / Family Anhydride building block, Separation membranes, High-performance polymers

Chemical Structure

4-Phenylethynylphthalic anhydride (PEPA) chemical structure, CAS 119389-05-8
4-Phenylethynylphthalic anhydride (PEPA) chemical structure, CAS 119389-05-8

Product Details

Purity >99%
Melting Point Tm = 152 °C
Appearance Pale yellow to yellow powder/crystal

MSDS Documentation

4-Phenylethynylphthalic anhydride (PEPA)4-Phenylethynylphthalic anhydride (PEPA) MSDS Sheet

Literature and Reviews

  1. Diels–Alder cycloaddition polymerization of highly aromatic polyimides and their multiblock copolymers, D. Cristurean et al., Polym. Chem., 12, 3160(2021); DOI: 10.1039/d1py00314c.
  2. Improved melt processabilities of thermosetting polyimide matrix resins for high temperature carbon fiber composite applications, H.-Y. Zhang et al., Polymers, 14, 965(2022); DOI: 10.3390/polym14050965.
  3. Liquid crystalline thermosetting (LCT) composites based triboelectric nanogenerator with intrinsic flame retardancy, M. Qadeer et al., Adv. Mater. Technol., 7(10), 2200002(2022); DOI: 10.1002/admt.202200002.
  4. Preparation and properties of modified phenylethynyl terminated polyimide with neodymium oxide, P. Zhang et al., Materials 15, 4148(2022); DOI: 10.3390/ma15124148.
  5. Synthesis, properties and gas separation performance of poly(arylene ether sulfone) containing imide pendant groups, Y. Yu et al., RSC Adv., 7, 42468(2017); DOI: 10.1039/c7ra07355k.

To the best of our knowledge the information provided here is accurate. The values provided are typical at the time of manufacture and may vary over time and from batch to batch. Products may have minor cosmetic differences (e.g. to the branding) compared to the photos on our website. All products are for laboratory and research and development use only.

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