Regulatory information osha hazards flammable liquid, target organ effect, toxic by inhalation. Gas phase cracking of dicyclopentadiene to produce. Usually it is obtained by cracking of dicyclopentadiene and is used immediately in a reaction. Dicyclopentadiene is coproduced in large quantities in the steam cracking of naphtha and gas oils to ethylene. This dimer can be restored by heating to give the monomer. I recently did a distillation of dicyclopentadiene bp 166 c to get cyclopentadiene bp 40 c. Kidney damage has been reported in rats exposed to dicyclopentadiene for 7 hours per day for 89 days at levels of 34 or 74 ppm in section 4 first aid measures eyes. Pesticide properties for dicyclopentadiene, including approvals, environmental. Large mammals including dogs, cats, rats, rabbits, hares, deer. 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. This new compound must be separated before the desired compound can be used.
Experiment 22 the dielsalder cycloaddition reaction pg. Dcpd products originate from high temperature cracking of petroleum fractions and are best characterized as highly reactive intermediates used for a. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10 h 12. Cyclopentadiene is an organic compound with the formula c 5 h 6. Cyclopentadiene dimer chemical reference number cas. The setup as instructed by my supervisor consisted of a simple watercooled liebig condenser.
The only effect that was observed was a male ratspecific nephropathy that is characteristic of the hyaline droplet nephropathy produced by a diverse group of compounds. We have not verified this information, and cannot guarantee that it is uptodate. Dicyclopentadiene osha z 1 a twa 5 ppm, 30 mgm3 acgih twa urt irr0. Dicyclopentadiene is coproduced in large quantities in the steam cracking of.
No workplace exposure level could be found in the literature but dicyclopentadiene is used as an intermediate for cyclodiene pesticides. Dicyclopentadiene c10h12 cid 6492 structure, chemical names. Its a colorless, waxy, flammable solid or liquid, with a camphorlike odor. The first step in the synthesis of cpru pph 3 2 cl is to crack the dicyclopentadiene dimer. This lab was a great way to get tangible reinforcement from what was taught in lecture. View lab report lab report 1 from che 211l at quinnipiac university. Cyclopentadiene is made by thermal cracking of its dimer, and on standing it slowly reverts to this species. We have tried to make it as accurate and useful as possible, but can take no responsibility for its use, misuse, or accuracy. Als environmental provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data. In the cracking of dicyclopentadiene, why is it necessary to distill the product very slowly. This information was last updated on march 23, 2005.
The dicyclopentadiene dimer c10h12 is broken down cracked to the. It is produced in bulk quantities through steam cracking of c5 petroleum products such. No chemicals in this material are subject to the reporting requirements of sara title iii, section 302. As dicyclopentadiene enters the air, it breaks down quickly into simpler, lesstoxic chemicals. Add 8 ml of hexane or petroleum ether, and then cool the solution in an ice bath. The distillation andor cracking of dicyclopentadiene should be carried out in an. This thermal cracking is merely the reverse of the dielsalder reaction, thus it is called a retro dielsalder reaction. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10h12. Previous question next question get more help from chegg. When pure cyclopentadiene is stored it also undergoes a dielsalder cycloaddition reaction and forms.
Bushy run research center, export, pa, tsca 8e submission by exxon chem amer doc id 888300464, odd doc id 8ehq02830364, microfiche no. Dicyclopentadiene is manufacturered from high temperature cracking of petroleum fractions in an ethylene manufacturing process. Dielsalder reactions chemical and biomolecular engineering. The dicyclopentadiene dimer c 10 h 12 is broken down cracked to the monomer c 5 h 6 cp. In the cracking of dicyclopentadiene, why is it ne.
Search results for dicyclopentadiene at sigmaaldrich. Cyclopentadiene dimer, 4,7 methano 3a,4,7,7a tetrahydroindene, dicyclopentadiene. You will start with a lab that has two hoods, working gas, water and air jets, and plenty. Insights into the dielsalder reactions between cyclopentadiene. The ld 50 for dicyclopentadiene given rats is 353 mgkg. The process for the production of cyclopentadiene by the substantially quantitative splitting or monomerizing of a dicyclopentadiene concentrate containing thermally stable dimers of isoprene and codimers of cyclopentadiene, isoprene and piperylene and having been obtained by the heat treatment of a c5 fraction of a pyrolysis petrol and its subsequent enrichment by fractional. Us3719718a process for the production of cyclopentadiene. In order to be of any use, the dimer must be cracked and distilled. The dimer endodcpd can be formed easily at room temperature although full conversion takes several days. The vapors are irritating to the eyes and respiratory system. Preparation of cyclopentadiene from dicyclopentadiene. Preparation of cyclopentadiene from its dimer journal of.
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 invention also includes a dicyclopentadiene cracking apparatus or system. Dicyclopentadiene wisconsin department of health services. Lab rats principal perry thinks chase is an alien duration. In this lab we will be studying the reaction of cyclopentadiene with maleic anhydride. Dicyclopentadiene is coproduced with ethylene from the c5 fraction in the steam cracking of naphtha and gas oils. The reaction product has been claimed to be solely endodcpd. Dicyclopentadiene is classified as moderately toxic. Optimum embodiments of the invention provide for about 98100% conversion of dicyclopentadiene to monomer at about 97100% purity. Dielsalder reaction of cyclopentadiene with maleic anhydride. Cracking of dicyclopentadiene before the beginning of lab the cyclopentadiene was prepared by a lab technician by cracking it.
And also state whether they will be racemix, and draw its 3d configuration. At its simplest, this dimerisation can be described as a. Three of four rats survived ten 6hour daily exposures at 250 ppm, and all survived 15 such exposures at 100 ppm. In the autoclave reactor, reaction temperature, reaction time, diluent, and inhibitors are investigated to study the effect of inhibiting oligomerization reactions. 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.
Liquidphase cracking of dicyclopentadiene by reactive. The revised idlh for cyclopentadiene is 750 ppm based on acute inhalation toxicity data in animals shashkina 1965. Ive tried to make a crack video for months, but every time i wasnt satisfied. Subject to polymerization if subjected to heat for prolonged periods or if contaminated. Fate of dicyclopentadiene in the environment prism university of. Dicyclopentadiene information about dicyclopentadiene is for educational purposes only. In case of contact, immediately flush eyes with plenty of water for a t least 15 minutes. When pure cyclopentadiene is stored it also undergoes a dielsalder cycloaddition reaction and forms dicyclopentadiene. Although the elevated temperature can boost the cracking of dcpd into. 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.
Dicyclopentadiene an overview sciencedirect topics. To predict the relative rates of reaction of dienes, use these rules. This colorless liquid has a strong and unpleasant odor. In case of contact, flush skin with plenty of water. The rate of monomer formation cracking becomes reasonable at temperatures above 150 c and approaching the boiling point of the dimer. The product is an interesting white crystalline structure that looks like snow.
Fischer 344 rats were exposed by inhalation to 0, 1, 5 or 50 ppm dicyclopentadiene dcpd vapor 6 hrday, 5 daysweek for weeks, followed by a week recovery period. Dicyclopentadiene dcpd, a dimer of cyclopentadiene, is a white crystalline chemical compound with camphorlike odor. To recover and purify the product, we used a recrystallizing technique by heating, cooling, and then filtering. Place 2 g of maleic anhydride in a 50ml erlenmeyer flask and dissolve it in 8 ml of ethyl acetate by warming on a hot plate. Please let a resonable explanation pertaining to dielsalder reactions. Dielsalder and melting point chem217labsfall07 openstax cnx. It was decided to use the 2hour lethal concentration data in mice rather than the 4hour lethal concentration data in rats so as not to magnify the conservatism already present in the. Lab rats principal from another planet part 2 duration. Solventfree dielsalder reactions of in situ generated. Health and environmental effects document for cyclopentadiene and dicyclopentadiene.
At room temperature, it is a clear light yellow color liquid with an acrid odor. Dicyclopentadiene vapor ninetyday inhalation study on rats and mice. Dicyclopentadiene should never be distilled to dryness since there is danger of explosion if peroxides are present. Cyclopentadiene dimerization and cracking dicyclopentadiene. It is used in the manufacturer of some pesticides, as a grass growth regulator and, in some instances, as a mammal repellent. The purpose of this lab is to introduce the concept of the melting point of an organic. This is achieved by using the fractional distillation set up shown in the photo. The reaction kinetics of cyclopentadiene dimerization. Dicyclopentadiene may react vigorously with oxidizing agents. Process for the vaporphase thermal cracking of dicyclopentadiene and a process for the manufacture of high purity dicyclopentadiene. If the polymerization takes place inside a container, the container may violently rupture. The distillation andor cracking of dicyclopentadiene should be carried out in an inert atmosphere to prevent the formation of peroxides.
Dicyclopentadiene cracking process boulder scientific. Vnb, the production rates of all the byproducts are increased as well. Cracking of dicyclopentadiene chemistry stack exchange. Als environmental does not sell chemicals, but offers analytical lab testing to determine the presence of various elements and chemical compounds. In other words, in the cracking of dicyclopentadiene, why is it necessary to distill the product very slowly. Subchronic toxicity study of dicyclopentadiene vapor in rats. Cyclopentadiene has a rather strong and disagreeable odor and. You have selected the maximum number of product attributes 3 to compare. The major use is in resins, particularly, unsaturated polyester resins.
The dicyclopentadiene will be cracked for you by your t. Degradation rates dropped significantly above ph 8. Dicyclopentadiene dcpd is typically a clear liquid with a fragrant strong musty odor. Diels alder reactions of cyclopentadiene brainmass. 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. Average rates of degradation, dcpd and other hydrocarbon 11 5. It will dissolve in water and evaporates quickly from water and soil surfaces. A reactive distillation process was developed for cracking dicyclopentadiene dcpd to produce cyclopentadiene cpd. May react exothermically with reducing agents to release hydrogen gas. Dicyclopentadiene appears as a liquid with an acrid odor.
Cyclopentadiene cpd and dicyclopentadiene dcpd are two important products obtained from oil cracking, which are interconvertable through a dielsalder reaction. 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 dcpd 3a,4,7,7atetrahydo4,7methano1hindene c10h12 general dicyclopentadiene or dcpd is the dimer of cyclopentadiene cpd formed by a dielsalder addition reaction. Check out the pictures below that highlight the product from the lab. 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. Animals were euthanized following completion of exposure at 2, 6, or. At room temperature, this cyclic diene dimerizes over the course of hours to give dicyclopentadiene via a dielsalder reaction. This monomer is prepared by dimerization of cyclopentadiene, which is in turn produced during cracking of oils. These findings indicate an overall low degree of systemic toxicity following subchronic inhalation exposure of dicyclopentadiene at exposure levels up to 50 ppm. I am still not satisfied, but i really wanted to post a crack video.
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