Dicyclopentadiene

Dicyclopentadiene (DCPD) is an organic hydrocarbon that is the dimer of cyclopentadiene. It is typically encountered as a colorless to pale-yellow solid with a sharp, characteristic odor. DCPD is relatively stable at ambient conditions but tends to polymerize if heated or contaminated with trace acids or bases, so inhibitors are commonly added for storage.

Industrially, DCPD is produced by the Diels–Alder dimerization of two cyclopentadiene molecules. It exists mainly as an endo/exo mixture of isomers. The compound is commonly cracked by heating to give cyclopentadiene monomer, which is used in various chemical processes, including the synthesis of organometallic compounds and as a monomer in ring-opening metathesis polymerization (ROMP).

One of the principal applications of DCPD is as a feedstock for producing polydicyclopentadiene (PDCPD) resins via ROMP or copolymers with other dienes. PDCPD resins impart high heat resistance, chemical resistance, and mechanical strength to coatings, composites, and structural components used in automotive, construction, and industrial equipment.

Safety: DCPD is flammable and can cause irritation to skin, eyes, and respiratory tract. It readily polymerizes, which can generate heat; storage is done under inhibitor and in well-ventilated areas away from heat sources. Handling requires protective equipment and proper ventilation; spills should be contained to prevent ignition. In case of contact, wash with water.