Cyclopentadiene cpd and dicyclopentadiene dcpd, which occur as by. The temperature of heating should not be above the temperature at which serious decomposition of the cyclopentadiene occurs and usually is below about 800 c. It is used in the manufacturer of some pesticides, as a grass growth regulator and, in some instances, as a mammal repellent. This monomer is prepared by dimerization of cyclopentadiene, which is in turn produced during cracking of oils. At room temperature, it is a white crystalline solid with a camphorlike odor.
Material may produce a serious, potentially fatal pneumonia if swallowed or vomited. Dicyclopentadiene an overview sciencedirect topics. The reaction kinetics of cyclopentadiene dimerization using. This is achieved by using the fractional distillation set up shown in the photo. In the autoclave reactor, reaction temperature, reaction time, diluent, and. Thus, commercial dicyclopentadiene is thermally decomposed cracking process to obtain cyclopentadiene by fractional distillation scheme 1. Cyclopentadiene has a rather strong and disagreeable odor and cracking has to be done in a fumehood. It is usually in the form of polymer because its monomer is easy to polymerize at room temperature. Dielsalder reaction dielsalder reaction 1 answer below.
Jan 25, 2012 what kind of reaction does the cracking of dicyclopentadiene represent. Also, when cooling a piece of equipment that contains the hot bottoms from the distillation or cracking of dicyclopentadiene, care should be taken to exclude air. Dicyclopentadiene dcpd 3a,4,7,7atetrahydo4,7methano1hindene c10h12 general dicyclopentadiene or dcpd is the dimer of cyclopentadiene cpd formed by a dielsalder addition reaction. Cyclopentadiene dimer chemical reference number cas. The dimer endodcpd can be formed easily at room temperature although full conversion takes several days.
Your new online msds binder is a place for you to store the material safety data sheets you need to deploy. Although olefin metathesis can be used to prepare a variety of thermosets from olefins, most of the new applications of this relatively new technology use dicyclopentadiene dcpd. This dimer can be restored by heating to give the monomer. A process of preparing cyclopentadiene from dicyclopentadiene, which comprises continuously passing dicyclopentadiene in vapor phase into a cracking zone at a pressure not above 500 mm. However, it can stay unchanged for a long time in soil and in. Onepot catalytic transformation of dicyclopentadiene to high. Dicyclopentadiene, 95%, stabilized with 100200 ppm ptertbutylcatechol catalog numbers. Due to the inconvenience of sampling with an impinger, we set out to find a solid sorbent tube to collect the dicyclopentadiene. Maintain a rate of distillation that does not exceed 23 dropssec of monomer passing from the water condenser to the. After twothirds of the dicyclopentadiene has been pyrolyzed during the course of 45 hours, the residue in the flask may tend to become viscous and a higher temperature for the pyrolysis will be required in order to obtain rapid distillation of cyclopentadiene. Aldrich 454338 page 6 of 7 ingestion harmful if swallowed. It is soluble in ethyl ether, ethyl alcohol and benzene while insoluble in water.
Dicyclopentadiene cracking process boulder scientific. This dimerisation already takes place at room temperature and its rate rapidly increases with elevated temperatures. Dicyclopentadiene is coproduced in large quantities in the steam cracking of naphtha and gas oils to ethylene. The process of producing highpurity cyclopentadiene cpd has. At its simplest, this dimerisation can be described as a. At room temperature, it is a clear light yellow color liquid with an acrid odor. Preparation of cyclopentadiene from dicyclopentadiene. Factors including cracking temperature, reaction time, and h2 to. The osha analytical laboratory recently received a set of field samples that required analysis for dicyclopentadiene. Cyclopentadiene material safety data sheet cas no 77736 sds.
Pure cyclopentadiene has to be stored at a low temperature. The process of producing highpurity cyclopentadiene cpd has been investigated, including a gas phase thermal cracking process of dicyclopentadiene dcpd in the presence of h2 on a continuous. Its a colorless, waxy, flammable solid or liquid, with a camphorlike odor. In such an event it is desirable to discard the residue while it is still hot. I speculate that it probably worked because the head temperature in all likelihood was below the bp of dicyclopentadiene cant say for sure, as i didnt measure temperature. The rate of monomer formation cracking becomes reasonable at temperatures above 150 c and approaching the boiling point of the dimer. Cyclopentadiene is an organic compound with the formula c5h6. Us2453044a process for producing cyclopentadiene and its. It is unstable under ordinary conditions and, at room temperature, dimerizes into dicyclopentadiene. Dcpd products from dow can best be characterized as highly reactive intermediates used for a wide range of resins, i. Safety data sheet crude dicyclopentadiene version 2. In other words, in the cracking of dicyclopentadiene, why is it necessary to distill the product very slowly. Liquidphase cracking of dicyclopentadiene by reactive distillation.
Dicyclopentadiene cracking process boulder scientific company. Diels alder reactions of cyclopentadiene brainmass. Flammable in the presence of a source of ignition when the temperature is above the flash point. This heating causes depolymerization to form cyclopentadiene. Dicyclopentadiene contains bht as stabilizer synonym. Preparation of high purity cyclopentadiene by the depolymerization. In the first step, cyclopentadiene is dimerized to give dicyclopentadiene by heat soaking the entire c5 fraction, either at normal pressure and 30 100 c over 5 24 hr or at elevated pressure and 140 150 c. The risk of the process is the coking problem with the high reaction temperatures involve. Cracking apparatus the dielsalder reaction of cyclopentadiene with maleic anhydride the dielsalder reaction that you will be performing between cyclopentadiene and maleic anhydride occurs rapidly at room temperature. Gas phase cracking of dicyclopentadiene to produce. Dicyclopentadiene is coproduced in large quantities in the steam cracking of naphtha and gas oils to et. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c10h12.
Solventfree dielsalder reactions of in situ generated. Usually it is obtained by cracking of dicyclopentadiene and is used immediately in a reaction. The reaction product has been claimed to be solely endodcpd. This colorless liquid has a strong and unpleasant odor. Dcpd products originate from high temperature cracking of petroleum fractions and are best characterized as highly reactive intermediates used for a. Preparation of cyclopentadiene from its dimer journal of. Stable at room temperature, but may form explosive peroxides ifstored in contact with air. First, tricyclopentadiene tcpd was prepared directly from the dissociationrecombination of dcpd at 200 c. At room temperature, this cyclic diene dimerizes over the course of hours to give dicyclopentadiene via a dielsalder reaction. If you were to attempt to distill the monomer from the dimer at say 60 c it would probably take a very long time due to the slow rate of monomer formation at that. What kind of reaction does the cracking of dicyclopentadiene represent. Usually it is obtained by cracking of dicyclopentadiene and is used immediately. May react exothermically with reducing agents to release hydrogen gas.
A reactive distillation process was developed for cracking dicyclopentadiene dcpd to produce cyclopentadiene cpd. To aid in product isolation, the entire reaction will. Dielsalder reaction of cyclopentadiene with maleic anhydride johnson, chad philip. Dicyclopentadiene should never be distilled to dryness since there is danger of explosion if peroxides are present. Signs and symptoms of exposure to the best of our knowledge, the chemical, physical, and toxicological properties have not been thoroughly investigated. Dicyclopentadiene is coproduced in large quantities in the steam cracking of. Dicyclopentadiene c10h12 cid 6492 structure, chemical names, physical. In addition to the thermodynamics research center trc data available from this site, much more physical and chemical property data is available from the following trc products. Dicyclopentadiene wisconsin department of health services. This and other undesirable side reactions are to be avoided if high yields of cyclopentadiene monomer are to be obtained. Mar 02, 1999 this invention provides an improved dicyclopentadiene cracking process which entails rapidly heating the dimer in a heat transfer fluid to the cracking temperature in the absence of the monomer and rapidly removing the cyclopentadiene monomer vapor from the heat transfer fluid prior to condensation to the liquid state. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10 h 12. The first step in the synthesis of cpru pph 3 2 cl is to crack the dicyclopentadiene dimer.
The distillation andor cracking of dicyclopentadiene should be carried out in an inert atmosphere to prevent the formation of peroxides. Cyclopentadiene and dicyclopentadiene cheung major. View lab report lab report 1 from che 211l at quinnipiac university. Explain how you can raise the temperature of 1 mol of. In this work, we demonstrated the first example of onepot catalytic synthesis of exothtcpd directly from dicyclopentadiene dcpd.
As dicyclopentadiene enters the air, it breaks down quickly into simpler, lesstoxic chemicals. The air samples had been collected with isopropyl alcohol impingers. Chemicalbook provide chemical industry users with dicyclopentadiene. The dicyclopentadiene dimer c 10 h 12 is broken down cracked to the monomer c 5 h 6 cp. Cyclopentadiene is an organic compound with the formula c 5 h 6.
Dicyclopentadiene may react vigorously with oxidizing agents. Increasing temperature increases the rate of the dicyclopentadiene cracking reaction. Us2453044a us289590a us28959039a us2453044a us 2453044 a us2453044 a us 2453044a us 289590 a us289590 a us 289590a us 28959039 a us28959039 a us 28959039a us 2453044 a us2453044 a us 2453044a authority us united states prior art keywords dimer dicyclopentadiene temperature cyclopentadiene depolymerization prior art date 19390811 legal status the legal. Cpd and is formed during high temperature cracking of petroleum fractions and recovered by distillation. Dicyclopentadiene, abbreviated dcpd, is the chemical compound with the formula c10h12. Cracking of dicyclopentadiene was my simple liebig condenser. It will dissolve in water and evaporates quickly from water and soil surfaces. Nov 30, 1990 dicyclopentadiene is obtained by cracking the dicyclopentadiene in the crude stream, separating the lowboiling cyclopentadiene by distillation, and allowing the concentrated cyclopentadiene to dimerize under controlled conditions kirkothmer, 1979. The major use is in resins, particularly, unsaturated polyester resins.
Yes gm should handle the issues but the tire companies. Add 3 ml of dry cyclopentadiene how was this formed. Experiment 14 the dielsalder cycloaddition reaction pg. Can undergo exothermic polymierization reactions in the presence of various catalysts such as acids or initiators, if subjected to heat for prolonged periods, or if contaminated. However, i have found that poor yields are obtained unless certain precautions are observed. A dangerous body temperature depends on a persons age. Dicyclopentadiene is manufacturered from high temperature cracking of petroleum fractions in an ethylene manufacturing process. Perfect methyl cyclopentadiene dimer provided by hydrocarbon. Dielsalder reaction of cyclopentadiene with maleic anhydride. I speculate that it probably worked because the head temperature in all likelihood was below the bp of dicyclopentadiene cant say for sure, as i didnt measure temperature there. Procedure the apparatus for the cracking of dicyclopentadiene to cyclopentadiene will be set up in the hood and will be used to prepare all of the cyclopentadiene needed for the dielsalder reaction and for the preparation of ferrocene.
Ou chemical safety data no longer updated more details. The reaction kinetics of cyclopentadiene dimerization. Cyclopentadiene is made by thermal cracking of its dimer, and on standing it slowly reverts to this species. Signal word danger page 1 of 8 cyclopentadiene cas no 77736 material safety data sheet sdsmsds. Cyclopentadiene cpd and dicyclopentadiene dcpd are two important products obtained from oil cracking, which are interconvertable through a dielsalder reaction. Qilong mcpd is rectified from c9 fraction, a byproduct of naphtha cracking.
The whole procedure was fulfilled in onepot by three steps. Liquidphase cracking of dicyclopentadiene by reactive. Other companies are charging thousands of dollars to set up accounts and give you access to their msds online database. Dicyclopentadiene wikimili, the best wikipedia reader. Dcpd cracks at temperatures above 140c to form two cpd molecules. The physical properties of pure cpd and dcpd are given below as well as some product specific. Show this material safety data sheet to the doctor in attendance. Solved when cracking dicyclopentadiene, why should the. Dangerous fire hazard when exposed to heat or flame. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10h12. Sigmaaldrich offers a number of dicyclopentadiene products.
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