Dicyclopentadiene

Dicyclopentadiene (CAS 77-73-6) is a cyclic diene monomer derived from the dimerization of cyclopentadiene.

Where is Dicyclopentadiene used?

• Unsaturated polyester resins: reduces styrene content, improves surface quality, lowers resin cost
• Fiberglass composites for automotive and construction panels
• Hydrocarbon resins: primary feedstock for C5/C9 resins in hot-melt adhesives, road-marking paints and printing inks
• Coatings and inks: fast-drying, high-gloss formulations for publication and packaging printing
• Ring-opening metathesis polymerization yields polydicyclopentadiene for structural and industrial molded parts
• It serves as a reactive building block in resin and polymer synthesis.
• Used in the production of ethylene-propylene-diene rubbers (EPDM).
• Standard-grade unsaturated polyester resins are produced from dicyclopentadiene of over 85% purity via a two-reaction-stage synthesis known as the water process.
• Can be used as a flame retardant for plastics.

Formulation notes

• Should be separated from strong oxidants.
• May react exothermically with reducing agents, releasing hydrogen gas.
• Can undergo exothermic polymerization in the presence of catalysts such as acids or initiators, if heated for prolonged periods, or if contaminated.

Typical specification

• Assay of at least 97.0%.
• Appears as a colourless to light yellow liquid.

Regulatory status

• Assigned UN number 2048 for transport.

Storage, packaging and handling

• Can form explosive peroxides.
• Must be stored only if stabilized.
• Should be stored in an area without drain or sewer access.
• Usually stored in the presence of butylated hydroxytoluene (BHT) as an antioxidant.

Frequently asked questions about Dicyclopentadiene

What purity grades of dicyclopentadiene are available for cracking to intermediates?

High-purity dicyclopentadiene of 93–95% by weight is cracked to give intermediates such as CPD and ENB, and can be upgraded to an ultra-pure grade of over 98% by weight.

How is dicyclopentadiene incorporated into unsaturated polyester resins?

In the production of dicyclopentadiene-containing UPR, a maleic anhydride addition product is first formed with water, then dicyclopentadiene reacts with other esterification monomers such as acids and glycols.

What are typical end uses of dicyclopentadiene-modified unsaturated polyester resins?

Dicyclopentadiene-modified unsaturated polyester resins are mostly used for hulls, decks, and bathroom fixtures.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.