Quick Search
Dicyclopentadiene, also known as DCPD and cyclopentadiene dimer, is a reactive tricyclic unsaturated hydrocarbon with CAS 77-73-6 and molecular formula C10H12, used in resin manufacture, specialty chemical synthesis and polymer production. Its two chemically different carbon-carbon double bonds and strained ring structure make DCPD a useful reactive building block. Depending on the process, the dimer undergoes chemical incorporation into resins, ring-opening metathesis polymerization or thermal dissociation to cyclopentadiene.
CAS No: 77-73-6
EC No: 201-052-9
Molecular formula: C10H12
Molecular weight: approx. 132.20 g/mol
WHAT IS DICYCLOPENTADIENE?
Dicyclopentadiene (DCPD, CAS 77-73-6) is the dimer of cyclopentadiene and an industrial feedstock for hydrocarbon resins, modified polyester resins and polydicyclopentadiene. The monomeric feedstock and the polymer made from it are different materials with different handling requirements.
Industrial DCPD is obtained from hydrocarbon cracking streams containing cyclopentadiene. Dimerization and separation processes recover the higher-boiling dimer, while further purification produces grades for different resin and synthesis applications.
Commercial selection involves more than a purity percentage. Co-dimers, residual cyclopentadiene, higher oligomers, sulfur, water and stabilizer content can influence storage and reaction behavior.
High-purity, endo-rich cyclopentadiene dimer may be a low-melting crystalline solid near room temperature. Commercial hydrocarbon mixtures may remain liquid because their composition changes freezing behavior. A description of DCPD as always liquid or always solid is therefore incomplete.
The endo and exo stereoisomers have different reactivity and physical properties. Isomer-specific values should not be transferred to an unspecified commercial grade without confirmation.
COMMON PRODUCT & CHEMICAL NAMES OF DICYCLOPENTADIENE:
Dicyclopentadiene
DCPD
Cyclopentadiene dimer
1,3-Cyclopentadiene dimer
3a,4,7,7a-Tetrahydro-4,7-methanoindene
Tricyclo[5.2.1.0(2,6)]deca-3,8-diene
The abbreviation DCPD and the dimer names refer to dicyclopentadiene. The methanoindene and tricyclodecadiene descriptions identify its ring system. The shorter abbreviation CPD refers to cyclopentadiene rather than the dimer.
Cyclopentadiene, CAS 542-92-7, is the monomer obtained by dissociation of DCPD and is not a synonym for the stored dimer. Polydicyclopentadiene, commonly written pDCPD, is a polymer, while hydrogenated DCPD derivatives are chemically different substances.
CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF DICYCLOPENTADIENE
Product name: Dicyclopentadiene
Common abbreviation: DCPD
Chemical name: Tricyclo[5.2.1.0(2,6)]deca-3,8-diene
CAS No: 77-73-6
EC / EINECS No: 201-052-9
Molecular formula: C10H12
Molecular weight: approx. 132.20 g/mol
Chemical class: Unsaturated tricyclic hydrocarbon
Main functions: Reactive resin feedstock, polymerizable monomer and chemical intermediate
These identifiers describe the general DCPD substance rather than a guaranteed isomer ratio or commercial purity. Additional CAS numbers copied from a broad synonym database should not be treated as interchangeable product identifiers. REACH registration information exists for dicyclopentadiene, but supplier coverage must be confirmed for the actual supply chain.
CHEMICAL STRUCTURE AND MOLECULAR PROPERTIES OF DICYCLOPENTADIENE
The DCPD framework contains a strained norbornene-type double bond and a second double bond in a cyclopentene portion of the molecule. The double bonds are not equivalent in ring strain or reactivity.
Its hydrocarbon structure contains no oxygen or nitrogen functional groups. Low polarity and limited water solubility are relevant to phase behavior, but these features alone do not establish a finished polymer's dielectric, moisture-resistance or mechanical performance.
HOW DOES DICYCLOPENTADIENE WORK AT THE MOLECULAR LEVEL?
In ring-opening metathesis polymerization, a suitable metal-carbene catalyst reacts with the strained olefin and enables polymer-chain growth. Further reactions involving remaining unsaturation can produce a crosslinked network. The catalyst, isomer composition and cure conditions influence the resulting pDCPD.
During thermal dissociation, cyclopentadiene dimer undergoes a retro-Diels-Alder reaction that generates cyclopentadiene. The reverse dimerization occurs readily, which distinguishes DCPD storage chemistry from ordinary solvent evaporation.
Main functions:
Supplying reactive unsaturation for resin chemistry
Providing a monomer for metathesis-derived thermosets
Acting as a precursor to cyclopentadiene
Serving as an intermediate for specialty derivatives
Temperature, catalysts, contamination, stabilizers and residence time affect DCPD reactions. Controlled polymerization during manufacture must be distinguished from unwanted reactions in storage or heated equipment.
PHYSICAL AND CHEMICAL PROPERTIES OF DICYCLOPENTADIENE
General technical characteristics:
Appearance: Colorless to pale yellow liquid, or white to colorless crystalline material depending on grade and temperature
Odor: Characteristic pungent or camphor-like odor
Molecular formula: C10H12
Molecular weight: approx. 132.20 g/mol
Chemical character: Reactive unsaturated hydrocarbon
Density of liquid material: typically approx. 0.97-0.99 g/cm3 near room temperature, grade-dependent
Melting behavior: High-purity endo-rich material commonly melts at approx. 32-34 °C
Boiling behavior: Published reference values are approx. 167-172 °C, with thermal dissociation relevant during heating
Flash point: Published examples vary, approximately 32-44 °C for some grades and methods
Water solubility: Low, a published supplier value is approx. 40 mg/L
Refractive index: approx. 1.51, with temperature and grade to be specified
Purity: Grade-specific, commercial supplier examples include minimum contents of 82%, 92% and 94%, while a laboratory product specifies at least 97% by GC
Stabilizer: Grade-specific, some commercial products contain BHT
The physical state of DCPD must be checked at the stated temperature. A density measured for liquid material does not prove that the same high-purity grade is liquid under every room-temperature condition.
Flash-point values depend on composition and test method. Published ranges are not a substitute for the delivered product's hazard classification. The hydrocarbon should be handled as a flammability and vapor-exposure concern even when it has crystallized.
GC composition, residual CPD and higher oligomers are useful purchasing parameters for cyclopentadiene dimer. Water, sulfur, peroxides and stabilizer content can also matter, particularly for catalyst-sensitive applications.
The figures above are indicative substance or identified-grade data rather than universal acceptance limits. For the actual viscosity, freezing profile and impurity specifications of the offered DCPD, please contact Ataman Kimya.
USE OF DICYCLOPENTADIENE IN ROMP AND THERMOSET DEVELOPMENT
Metathesis-derived pDCPD provides a route to molded thermoset parts and composite matrices. Low liquid-monomer viscosity can assist mold filling or reinforcement impregnation before polymerization.
The advantages of the final polymer depend on catalyst choice, conversion, crosslinking, reinforcement and processing. DCPD monomer is not a ready-to-use cured resin, and a published result for one catalyst system does not define all commercial molding formulations.
Cure development should include calorimetry, working time, conversion and residual monomer. The heat generated by DCPD polymerization requires assessment before increasing sample thickness or batch size.
SECTORS AND INDUSTRIAL APPLICATIONS OF DICYCLOPENTADIENE
The reactive dimer is used upstream in polymer and chemical manufacture, with downstream products serving several industries.
Main areas of use:
Hydrocarbon resin manufacture
Modified unsaturated polyester resins
Metathesis-derived thermosets
Reinforced polymer composites
Coating, ink and adhesive resin intermediates
Specialty cyclopentadiene chemistry
DICYCLOPENTADIENE IN HYDROCARBON RESINS
Purpose: Manufacture resin structures for selected adhesive, coating or ink applications.
Function: Supply a reactive hydrocarbon feedstock.
Performance effect: Contribute to resin architecture and compatibility.
Limitations: Softening point, color and adhesive performance depend on the complete resin process.
DICYCLOPENTADIENE IN MODIFIED POLYESTERS
Purpose: Produce DCPD-modified unsaturated polyester systems.
Function: Participate chemically in resin manufacture.
Performance effect: Modify resin structure and formulation behavior.
Limitations: Lower shrinkage, reduced styrene emissions or faster cure are formulation-specific outcomes, not universal guarantees of the raw material.
DICYCLOPENTADIENE IN MOLDED PARTS AND COMPOSITES
Purpose: Prepare pDCPD matrices for shaped components.
Function: Act as the reactive monomer in a designed catalyst system.
Performance effect: Enable formation of a crosslinked thermoset.
Limitations: Mechanical, dielectric and fire performance require testing on the final part. The monomer is not inherently a flame-retardant additive.
WHICH PROBLEMS CAN DICYCLOPENTADIENE HELP SOLVE?
Need for a reactive hydrocarbon resin building block
DCPD supplies unsaturation for suitable resin synthesis routes, but the target resin must be designed and tested.
Demand for low-viscosity thermoset feedstocks
Liquid cyclopentadiene dimer can support filling or impregnation before cure. Working temperature and crystallization must be controlled.
Need for a cyclopentadiene precursor
The dimer provides an established chemical source of CPD through controlled thermal dissociation. This is a professional synthesis operation requiring appropriate equipment.
Inconsistent polymerization response
Specifying purity, isomer composition and stabilizer content helps investigate DCPD variation. Catalyst selection and process conditions remain essential.
THINGS TO CONSIDER WHEN USING DICYCLOPENTADIENE
A common mistake is applying a single liquid-property table to every grade of DCPD. Composition and temperature can change both physical state and reaction behavior.
Identify the intended resin or synthesis route before grade selection.
Record assay, isomer information and relevant co-dimers.
Confirm inhibitor identity, content and monitoring requirements.
Assess catalyst compatibility before changing raw-material grade.
Control heating and avoid prolonged uncontrolled warm storage.
Prevent contamination, static discharge and vapor release.
Measure reaction heat and working time before scale-up.
Professional DCPD handling requires closed transfer or effective local extraction and equipment suitable for flammable materials. Odor is not a reliable measure of safe exposure.
INITIAL FORMULATION APPROACHES FOR DICYCLOPENTADIENE
The following calculated compositions are illustrative laboratory comparison points, not validated commercial molding formulations or operating instructions. Percentages are by weight. Both use a first-generation ruthenium benzylidene metathesis catalyst of nominal molar mass approximately 822.9 g/mol and literature-represented monomer-to-catalyst molar ratios. Use a DCPD grade demonstrated to be compatible with that catalyst.
EXAMPLE 1: DICYCLOPENTADIENE ROMP SCREEN AT LOWER CATALYST LOADING
Components:
Dicyclopentadiene, catalyst-compatible grade: 99.875%
First-generation ruthenium benzylidene metathesis catalyst: 0.125%
Total: 100.000%
Calculated DCPD/catalyst molar ratio: approx. 5,000:1, assuming pure DCPD and neat catalyst.
Evaluation criteria:
Catalyst dissolution and mixture homogeneity
Working time and calorimetric heat release
Conversion and residual monomer
Glass transition behavior
Mechanical properties after a separately validated cure
Safety note: Prepare only under professional laboratory controls after assessing reaction exotherm and containment. The listed percentages do not establish a safe batch size, temperature or cure schedule.
EXAMPLE 2: DICYCLOPENTADIENE ROMP SCREEN AT HIGHER CATALYST LOADING
Components:
Dicyclopentadiene, the same grade as Example 1: 99.690%
First-generation ruthenium benzylidene metathesis catalyst: 0.310%
Total: 100.000%
Calculated DCPD/catalyst molar ratio: approx. 2,000:1, assuming pure DCPD and neat catalyst.
Evaluation criteria:
Change in working time relative to Example 1
Peak heat-release rate and temperature rise
Conversion and network development
Residual catalyst and monomer
Comparison of final thermal and mechanical properties
Safety note: Higher catalyst loading can substantially alter reaction rate. Do not use these calculations for a different catalyst or a catalyst solution without recalculating and validating the complete system.
DICYCLOPENTADIENE SIMILAR PRODUCTS AND ALTERNATIVES
An alternative must be chosen for the intended chemistry, not merely for a similar hydrocarbon name or boiling range.
DICYCLOPENTADIENE AND CYCLOPENTADIENE
CPD is the smaller monomer and has different volatility and storage behavior. It is not an equal-weight substitute for DCPD in a resin formulation.
DICYCLOPENTADIENE AND NORBORNENE DERIVATIVES
Other strained cyclic olefins can participate in metathesis chemistry, but functionality and polymer properties differ. Catalyst response must be evaluated separately.
DICYCLOPENTADIENE AND COMMERCIAL C5 HYDROCARBON FEEDSTOCKS
Mixed C5 streams contain different reactive components. Their suitability for hydrocarbon resin synthesis does not establish equivalence to a purified DCPD grade.
DICYCLOPENTADIENE AND POLYDICYCLOPENTADIENE
pDCPD is the resulting polymer rather than an alternative monomer. Selecting a finished resin system requires attention to its formulation and cure package.
Laboratory and application validation should confirm every proposed substitution.
QUALITY CONTROL AND PURCHASING CRITERIA FOR DICYCLOPENTADIENE
Define the intended DCPD reaction and delivery form before comparing prices.
Information to clarify and review before purchasing:
CAS 77-73-6 and EC 201-052-9
Assay and isomer composition
Residual CPD, co-dimers and higher oligomers
Water, sulfur and relevant aromatic impurities
Peroxide and stabilizer requirements
Physical state and transfer-temperature requirements
Catalyst or resin-process compatibility
Batch COA, TDS and current local SDS
Packaging, transport route, quantity and delivery conditions
A COA reports batch-specific results or conformity, a TDS describes technical properties, and an SDS communicates hazards and handling. For catalyst-sensitive DCPD applications, a nominal assay alone is insufficient purchasing evidence.
Purity, impurity control, stabilization, packaging and delivery terms affect quotation comparisons. For current price and supply availability, please contact Ataman Kimya.
STORAGE AND HANDLING OF DICYCLOPENTADIENE
Keep DCPD in suitable closed containers or engineered storage systems, protected from heat, ignition sources and contamination. Provide temperature control and follow the delivered grade's stabilization and headspace instructions. Do not change the inhibitor or blanketing arrangement without supplier and process review.
Crystallization does not justify uncontrolled heating. Any warming needed for transfer must use an approved method that avoids hot spots and monitors temperature. The required storage temperature and maximum residence time depend on the grade and installation.
Use bonding, grounding and suitable equipment during DCPD transfer. Segregate incompatible oxidizers and reactive contaminants. Aged or suspect material should be assessed for composition, peroxide formation and stabilizer condition before reuse.
Published industrial transport information identifies UN 2048, DICYCLOPENTADIENE, class 3, packing group III. Confirm the supplied grade's actual classification and environmental markings for the shipment.
Contain spills without releasing vapors unnecessarily, prevent entry into drains and arrange authorized recovery or disposal. Large or uncontrolled releases require trained emergency responders.
SAFETY INFORMATION OF DICYCLOPENTADIENE
DCPD presents fire, inhalation and environmental hazards. A reviewed industrial European SDS lists H225, highly flammable liquid and vapor, H302, harmful if swallowed, H304, aspiration hazard, and H330, fatal if inhaled. Other supplier documents may classify the physical form differently, so this abbreviated list is not the complete label for every grade.
Confirm all current H statements and protective measures for the delivered cyclopentadiene dimer. Use chemical-resistant gloves, eye protection, suitable clothing and an exposure-control system appropriate to vapor and mist. Respiratory protection must follow the workplace assessment.
After inhalation exposure, move the person to fresh air and obtain urgent medical assistance. For ingestion, seek immediate medical help and do not induce vomiting. Rinse exposed eyes promptly and wash contaminated skin while removing affected clothing.
Prolonged heating or contamination can cause hazardous reactions and pressure development. Fire response requires suitable extinguishing equipment and trained personnel. Prevent DCPD from reaching waterways and manage residues and contaminated packaging as required locally.
Industrial use does not establish suitability as a cosmetic, food or pharmaceutical ingredient. For current regulatory and REACH supply-chain documentation, please contact Ataman Kimya.
SUPPLY OF DICYCLOPENTADIENE FROM ATAMAN KIMYA
For dicyclopentadiene supply inquiries, contact Ataman Kimya with the intended resin or synthesis application. Confirm grade, stabilization, documentation and delivery conditions at quotation stage.
Sharing the following information in a quotation request helps evaluate the correct DCPD product:
Target reaction or resin system
Required assay and impurity limits
Isomer and inhibitor requirements
Quantity, packaging and receiving capability
Delivery location and schedule
FREQUENTLY ASKED QUESTIONS ABOUT DICYCLOPENTADIENE
What is dicyclopentadiene?
DCPD is cyclopentadiene dimer, a reactive hydrocarbon used in resin and chemical manufacture.
What is the CAS number of dicyclopentadiene?
The general substance CAS number is 77-73-6.
What is the EC number of dicyclopentadiene?
The EC number is 201-052-9.
What is the formula of dicyclopentadiene?
Its formula is C10H12 and its molecular weight is approximately 132.20 g/mol.
Is dicyclopentadiene always liquid?
No. High-purity endo-rich DCPD can crystallize near room temperature, while commercial mixtures may remain liquid.
Is minus 32 °C the general melting point of dicyclopentadiene?
No. High-purity endo-rich material commonly melts near positive 32-34 °C.
Is dicyclopentadiene readily water-soluble?
No. DCPD has low water solubility and should not be treated as an aqueous ingredient.
Is dicyclopentadiene the same as cyclopentadiene?
No. CPD is the monomer and DCPD is its dimer.
How does dicyclopentadiene produce pDCPD?
A suitable metathesis catalyst enables ring-opening polymerization and network formation.
Can any DCPD grade be used with any ROMP catalyst?
No. Purity, inhibitors, contaminants and isomer distribution can influence catalyst behavior.
Does dicyclopentadiene require stabilization?
Many commercial grades are stabilized. Follow the exact supplied grade's storage and monitoring requirements.
Is dicyclopentadiene a flame retardant?
It should not be described as a general flame-retardant additive merely because it is used to synthesize some specialty products.
Can dicyclopentadiene be heated freely to melt it?
No. Approved temperature control and suitable equipment are needed because heat affects reactivity and vapor generation.
What is the UN number of dicyclopentadiene?
Published industrial transport information identifies UN 2048, class 3, packing group III.
Is dicyclopentadiene hazardous?
Yes. Fire, acute exposure, environmental release and uncontrolled-reaction hazards require professional controls.
Which documents should be requested for dicyclopentadiene?
Obtain the current TDS, local SDS, batch COA and stabilization and impurity information relevant to the application.
DICYCLOPENTADIENE - TECHNICAL SUMMARY
Dicyclopentadiene, abbreviated DCPD, is a tricyclic unsaturated hydrocarbon and cyclopentadiene dimer. Its identifiers are CAS 77-73-6, EC 201-052-9 and molecular formula C10H12.
Commercial quality is defined by purity, isomer composition, co-dimers, residual CPD, oligomers and stabilization. Physical state must be interpreted with composition and temperature.
The dimer serves hydrocarbon resin manufacture, modified polyester chemistry, metathesis-derived thermosets and specialty synthesis. DCPD monomer and pDCPD polymer are distinct materials.
Its strained double bond supports ring-opening metathesis chemistry, while heating can cause dissociation to CPD. Process benefits require a validated catalyst, formulation and thermal-control strategy.
Manage flammability, toxic exposure and environmental release, and follow grade-specific storage instructions. Ataman Kimya can clarify the offered DCPD grade and supply conditions.
Dicyclopentadiene can be sourced from ATAMAN KİMYA. For further information and supply inquiries about dicyclopentadiene, please contact ATAMAN KİMYA.
