The distillation andor cracking of dicyclopentadiene should be carried out in an inert atmosphere to prevent the formation of peroxides. Preparation of cyclopentadiene from its dimer journal of. The invention also includes a dicyclopentadiene cracking apparatus or system. The first step in the synthesis of cpru pph 3 2 cl is to crack the dicyclopentadiene dimer. Sigmaaldrich 3050 spruce street saint louis mo 63103 usa telephone. Dcpd products originate from high temperature cracking of petroleum fractions and are best characterized as highly reactive intermediates used for a. The original fivemembered ring of the diene is still present, however. Cdc niosh pocket guide to chemical hazards dicyclopentadiene.
Not specified, most likely a prism, grating, or hybrid spectrometer digitized by nist from hard copy. The dicyclopentadiene and the impurities are returned to the cracking zone or. You have selected the maximum number of product attributes 3 to compare. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10 h 12.
The reaction product has been claimed to be solely endodcpd. Dielsalder reactions chemical and biomolecular engineering. The reaction kinetics of cyclopentadiene dimerization. Dicyclopentadiene osha z 1 a twa 5 ppm, 30 mgm3 acgih twa urt irr0. The dicyclopentadiene is added at a rate sufficient to maintain a continuous. Usually it is obtained by cracking of dicyclopentadiene and is used immediately. Dielsalder reaction of cyclopentadiene with maleic anhydride johnson, chad philip. Dicyclopentadiene may react vigorously with oxidizing agents. Abstract the objective of this experiment was to crack dicyclopentadiene to create two molecules of cyclopentadiene, and then perform a dielsalder reaction by reacting the diene with maleic anhydride, the dienophile, to create cisnorbornene5,6endodicarboxylic anhydride. The cracking process requires a very high temperature of 300 c.
Liquidphase cracking of dicyclopentadiene by reactive distillation. Dicyclopentadiene is coproduced in large quantities in the steam cracking of. The reaction kinetics of cyclopentadiene dimerization using. Dcpd products originate from high temperature cracking of petroleum fractions and are best characterized as highly reactive intermediates used for a wide range of resins, i. Ill stick to my day job in organic chemistry, we study the reactions and properties that govern organic life. The largest consumption of dicyclopentadiene is linked to the production of resins including unsaturated polyester resins, petroleum resins, terpolymers, polynorbornenes, and. A reactive distillation process was developed for cracking dicyclopentadiene dcpd to produce cyclopentadiene cpd.
Dicyclopentadienepalladium dichloride and cycloocta1,5dienepalladium. The mass of cyclopentadiene that was collected was 0. And they said this is and ene reaction but i couldnt understand how this reaction is subset of ene reaction and how ester group is made. A meta description is an html tag in the html code of your website, which allows you to customize a section of text that describes the page itself. Dicyclopentadiene is a manmade substance produced by heating crude oil products. Can undergo exothermic polymierization reactions in the presence of various catalysts such as acids or initiators. Cracking cp you should be aware that cyclopentadiene cp will spontaneously react with itself, so it can only be stored as the dimer. The dicyclopentadiene is added cautiously to the hot oil. It will dissolve in water and evaporates quickly from water and soil surfaces. Dicyclopentadiene is coproduced with ethylene from the c5 fraction in the steam cracking of naphtha and gas oils. Cyclopentadiene dimer chemical reference number cas.
A reactive distillation process was developed for cracking dicyclopentadiene dcpd to produce cyclo pentadiene cpd. The setup as instructed by my supervisor consisted of a simple watercooled liebig condenser. Jan 23, 2016 i saw in books that reaction between dicyclopentadiene and maleic acid result in dicyclopentadiene maleat ester. Gas phase cracking of dicyclopentadiene to produce. Kommerziell erhaltliches dicyclopentadien iupacname.
The experimental procedure of obtaining cyclopentadiene followed the work from magnusson and eastwood and coworkers. Dicyclopentadiene dcpd, a dimer of cyclopentadiene, is a white crystalline chemical compound with camphorlike odor. 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. Heating up the cp dimer with crack it back to the monomer. Dicyclopentadiene cracking process boulder scientific. The claim 1 method wherein said body of heat transfer fluid is maintained within said reaction vessel. The claim 1 or claim 2 method, wherein said heat transfer fluid is diphenyl. 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. May react exothermically with reducing agents to release hydrogen gas. Top, phase change data, reaction thermochemistry data, gas phase ion energetics data, mass spectrum electron ionization, references, notes data compiled by. It is produced in bulk quantities through steam cracking of c5 petroleum products such as gas oils, naphtha, and crude oil. I recently did a distillation of dicyclopentadiene bp 166 c to get cyclopentadiene bp 40 c.
Chevron phillips chemical produces crude dcpd in sweeny, texas. 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. The largest consumption of dicyclopentadiene is linked to the production of resins including unsaturated polyester resins, petroleum resins, terpolymers, polynorbornenes, and other cyclic olefin polymers. 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.
Dicyclopentadiene is classified as moderately toxic. The cracking can be accomplished by distilling dicyclopentadiene under atmospheric pressure. Cyclopentadiene and dicyclopentadiene cheung major. The cyclopentadiene distills at 42c, but the temperature may go a few degrees higher due to superheating. Dicyclopentadiene dicyclopentadiene dcpd dicyclopentadiene a. However, it can stay unchanged for a long time in soil and in. Experiment 22 the dielsalder cycloaddition reaction pg. Preparation of cyclopentadiene from dicyclopentadiene. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c10h12.
Nov 20, 20 to crack the dicyclopentadiene, we used fractional distillation, which involves boiling the mixture to remove a certain compound by recondensing it. Dicyclopentadiene wisconsin department of health services. 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. The dissociation to the monomer is a monomolecular reaction. Dicyclopentadiene cracking process boulder scientific company.
It plays a role in how your page is seen by search engine crawlers, and how it appears in serps. This thermal cracking is merely the reverse of the dielsalder reaction, thus it is called a retro dielsalder reaction. At room temperature, it is a clear light yellow color liquid with an acrid odor. The flask containing dicyclopentadiene is now heated by means of an electric heating mantle or oil bath to approximately 160, or until cyclopentadiene distils smoothly at 3846 and a little dicyclopentadiene refluxes from the coldfinger friedrichs condenser. Undergoes a spontaneous dimerization at room temperature to give dicyclopentadiene c10h12, cas no. What kind of reaction does the cracking of dicyclopentadiene represent. Cyclopentadiene is a highly reactive diene in the dielsalder reaction because minimal distortion of the diene is. Diels alder reactions of cyclopentadiene brainmass. Jan 25, 2012 what kind of reaction does the cracking of dicyclopentadiene represent. When pure cyclopentadiene is stored it also undergoes a dielsalder cycloaddition reaction and forms dicyclopentadiene. In the autoclave reactor, reaction temperature, reaction time, diluent, and inhibitors are investigated to study the effect of inhibiting oligomerization reactions. Kinetic and thermodynamic control in the dielsalder reaction.
Cracking of dicyclopentadiene performed by your instructor, see figure l 2. Dicyclopentadiene from dicyclopentadiene reserve 1 directed to the cracking chamber 7 through line 5. The ld 50 for dicyclopentadiene given rats is 353 mgkg. This monomer is prepared by dimerization of cyclopentadiene, which is in turn produced during cracking of oils. As shown in figure 4, cyclopentadiene will react with a dienophile to produce a new sixmembered ring.
Safety data sheet maryville, mo a university in missouri. For the majority, we examine molecules and reactions that contain carbon, hydrogen, oxygen, and nitrogen. The reaction for this reversible process is shown below. Cdc niosh pocket guide to chemical hazards cyclopentadiene. Regulatory information osha hazards flammable liquid, target organ effect, toxic by inhalation. The dielsalder condensation between maleates and hexadiene is not observed as a side reaction in these conditions. Cracking of dicyclopentadiene chemistry stack exchange.
Dicyclopentadiene should never be distilled to dryness since there is danger of explosion if peroxides are present. After twothirds of the dicyclopentadiene has been pyrolyzed during the course of 45 hours, the residue in the flask may. Metering pumps 3 and 4 are employed in order to maintain a constant level of material in the cracking chamber. At the boiling point of dicyclopentadiene, equilibration with the monomer is rapid. Cyclopentadiene has a much lower boiling point than the original substance, so we were able to remove it and use for the 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. This is achieved by using the fractional distillation set up shown in the photo. Dielsalder reaction of cyclopentadiene with maleic anhydride. Cyclopentadiene is made by thermal cracking of its dimer, and on standing it slowly reverts to this species. At its simplest, this dimerisation can be described as a. As dicyclopentadiene enters the air, it breaks down quickly into simpler, lesstoxic chemicals. Cyclopentadiene cpd and dicyclopentadiene dcpd are two important products obtained from oil cracking, which are interconvertable through a dielsalder reaction. If your institution is not listed, please contact your librarian.
Dicyclopentadiene is obtained in certain hydrocarbon fractions resulting as. Liquidphase cracking of dicyclopentadiene by reactive. Dicyclopentadiene an overview sciencedirect topics. The exo isomer of dcp was found to be more than an order of magnitude more reactive than the endo isomer. In a method for cracking dicyclopentadiene to produce cyclopentadiene monomer.
Dicyclopentadiene dcpd 3a,4,7,7atetrahydo4,7methano1hindene c10h12 general dicyclopentadiene or dcpd is the dimer of cyclopentadiene cpd formed by a dielsalder addition reaction. The objective of this experiment was to crack dicyclopentadiene into two molecules of cyclopentadiene and mix cyclopentadiene with maleic anhydride to synthesize. As you may recall, cyclopentadiene is a particularly reactive diene, due to. Jul 19, 2011 this week youll be creating a product via the dielsalder reaction. Dielsalder reaction is reversible by cracking dicyclopentadiene using slow distillation and keeping the cyclopentadiene cold. Type part of your institution name for a list of matches. An uncontrolled cracking of dcpd reverse diels alder reaction with. The dimer endodcpd can be formed easily at room temperature although full conversion takes several days. If the polymerization takes place inside a container, the container may violently rupture. Subject to polymerization if subjected to heat for prolonged periods or if contaminated. This new compound must be separated before the desired compound can be used. In the autoclave reactor, reaction temperature, reaction time, diluent, and. The methylene group is extremely reactive and condenses with.
Cyclopentadiene is an organic compound with the formula c5h6. Cracking of dicyclopentadiene before the beginning of lab the cyclopentadiene was prepared by a lab technician by cracking it. Solution 10% ccl4 for 380030, 10% cs2 for 30450 cm1. And also state whether they will be racemix, and draw its 3d configuration. Solventfree dielsalder reactions of in situ generated. The major use is in resins, particularly, unsaturated polyester resins. Mar 02, 1999 various dicyclopentadiene cracking methods are known. The reaction is strongly exothermic hazardous chemicals desk reference, p. The exo isomer of dcp was found to be more than an order of magnitude more reactive than the.
Dcpd is a cyclic hydrocarbon that appears as colorless crystals, soluble in ethanol, diethyl ether, and acetic acid. Information and translations of dicyclopentadiene in the most comprehensive dictionary definitions resource on the web. The rate of monomer formation cracking becomes reasonable at temperatures above 150 c and approaching the boiling point of the dimer. Optimum embodiments of the invention provide for about 98100% conversion of dicyclopentadiene to monomer at about 97100% purity. Its a colorless, waxy, flammable solid or liquid, with a camphorlike odor. Dicyclopentadiene is coproduced in large quantities in the steam cracking of naphtha and gas oils to ethylene. Dicyclopentadiene appears as a liquid with an acrid odor. Cyclopentadiene dimerization and cracking dicyclopentadiene. In other words, in the cracking of dicyclopentadiene, why is it necessary to distill the product very slowly.
Cyclopentadiene dimer, 4,7 methano 3a,4,7,7a tetrahydroindene, dicyclopentadiene. I saw in books that reaction between dicyclopentadiene and maleic acid result in dicyclopentadienemaleat ester. The process of producing highpurity cyclopentadiene cpd has been. Dicyclopentadiene or dcpd is the dimer of cyclopentadiene cpd formed by a dielsalder addition reaction. Robota 1971 described a liquid phase cracking of dcpd in a. Experiment 14 the dielsalder cycloaddition reaction pg. No workplace exposure level could be found in the literature but dicyclopentadiene is used as an intermediate for cyclodiene pesticides. The auxiliary liquid is also directed from auxiliary liquid reserve 2 to the cracking chamber through line 6. The vapors are irritating to the eyes and respiratory system. The dicyclopentadiene dimer c 10 h 12 is broken down cracked to the monomer c 5 h 6 cp.
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