Procedure for preparing cyclopentadiene from its dimer. Dielsalder reaction is reversible by cracking dicyclopentadiene using slow distillation and keeping the cyclopentadiene cold. Process for the vaporphase thermal cracking of dicyclopentadiene and a process for the manufacture of high purity dicyclopentadiene apr 16, 1992 maruzen petrochemical co. Dicyclopentadiene 5 was purchased from aldrich 95% minimum, 9010 endolexo and further purified as described in the literature prior to polymerization. The claim 1 or claim 2 method, wherein said heat transfer fluid is diphenyl. A typical procedure involves the treatment of a 1aminoethylsubstituted butadiene with maleic anhydride at 0 degc to room temperature for 20. Dicyclopentadiene dcpd is typically a clear liquid with a fragrant strong musty odor. 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.
Place 2 g of maleic anhydride in a 50ml erlenmeyer flask and. Dicyclopentadiene is primarily used in unsaturated. 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. Liquidphase cracking of dicyclopentadiene by reactive distillation. Us patent for process for the vaporphase thermal cracking of. Dicyclopentadiene is coproduced in large quantities in the steam cracking of. The dicyclopentadiene dimer c10h12 is broken down cracked to the. Follow the written procedure using 10 ml of dicyclopentadiene in a 50 ml round bottom with a 25 ml round bottom flask as the receiver. Cyclopentadiene, which will be used in this experiment cannot be purchased commercially, and must be prepare in the lab by thermally cracking dicyclopentadiene. Simply put, hydrocarbon cracking is the process of breaking a longchain of hydrocarbons into short ones.
Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10 h 12. Us patent for process for the vaporphase thermal cracking. Cracking of dicyclopentadiene before the beginning of lab the cyclopentadiene was prepared by a lab technician by cracking it. As dicyclopentadiene enters the air, it breaks down quickly into simpler, lesstoxic chemicals. Dicyclopentadiene is coproduced in large quantities in the steam cracking of naphtha and gas oils to ethylene. When pure cyclopentadiene is stored it also undergoes a dielsalder cycloaddition reaction and forms. Thus, when cyclopentadiene is obtained by cracking of dicyclopentadiene, one can expect, at best, an overall 6570% reaction yield with respect to dicyclopentadiene. Experimental procedure cracking dicyclopentadiene to obtain. Preparation of cyclopentadiene from its dimer journal of. The first step in the synthesis of cpru pph 3 2 cl is to crack the dicyclopentadiene dimer.
Cracking is the breakdown of a large alkane into smaller, more useful alkenes. Characterization of the proteins from vigna unguiculata seeds. However, this dielsalder reaction is reversible by cracking dicyclopentadiene using slow distillation and keeping the cyclopentadiene cold. Dielsalder reaction of cyclopentadiene with maleic anhydride. This contribution presents further information about the mechanism of the crosslinking reaction which occurs during the polymerization of dicyclopentadiene with the classical catalyst, wcl 6 et 2 alcl 1. Cyclopentadiene dimerization and cracking dicyclopentadiene b. In the cracking of dicyclopentadiene, why is it necessary to distill the product very slowly. The dow chemical company dow encourages customers and potential. Norbornene acros, 99% was vacuum transferred to a schlenk tube prior to use. If distillation occurs at a faster rate, then it would be harder to handle. The experimental procedure of obtaining cyclopentadiene followed the work from magnusson and eastwood and coworkers. The sensitivity of the analytical procedure over a concentration range of 0. The equipment consists of a 100 ml round bot tom flask fitted with a claisen head, a condenser takeoff, a thermometer, a condenser, a receiver adapter, and a receiver cooled in an ice bath. Cracking is the most important process for the commercial production of gasoline and diesel fuel.
The cracking process requires a very high temperature of 300 c. 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. Us patent for dicyclopentadiene cracking process patent. However, it can stay unchanged for a long time in soil and in. Cyclopentadiene is an organic compound with the formula c 5 h 6.
The dicyclopentadiene will be cracked for you by your t. The sensitivity is determined by the slope of the calibration. Cracking of dicyclopentadiene was my simple liebig condenser. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or longchain hydrocarbons are broken down into simpler. Dicyclopentadiene may react vigorously with oxidizing agents. Therefore, a procedure that allows use of dicyclopentadiene directly would have important practical advantages. Dicyclopentadiene wisconsin department of health services. Experimental procedure part a cracking of dicyclopentadiene. The distillation andor cracking of dicyclopentadiene should be carried out in an inert atmosphere to prevent the formation of peroxides. Cracking of dicyclopentadiene chemistry stack exchange. Finally, such a procedure may allow isolation of stereoisomers. It is formed by the spontaneous dimerization of cyclopentadiene at room temperature, and above 160 c, dcdp dissociates into cyclopentadiene again. A process and a system for cracking dicyclopentadiene are disclosed pursuant to the process preheated dicyclopentadiene is introduced into a heated transfer fluid sufficiently below the transfer fluid surface to accomplish substantially complete conversion of said dicyclopentadiene to monomeric cyclopentadiene vapor. Dicyclopentadiene dicyclopentadiene dcpd dicyclopentadiene a.
The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. In a method for cracking dicyclopentadiene to produce cyclopentadiene monomer. 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. 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. The major use is in resins, particularly, unsaturated polyester resins. Dicyclopentadiene, abbreviated dcpd, is a chemical compound with formula c 10h12. At room temperature, this cyclic diene dimerizes over the course of hours to give. Another procedure involves adding dicyclopentadiene to a hot liquid, e.
The claim 1 method wherein said body of heat transfer fluid is maintained within said reaction vessel. Economics of dicyclopentadiene dcpd production processes. Figure one demonstrates the fractional distillation set up which was used to crack dicyclopentadiene. However, this dielsalder reaction is reversible by cracking dicyclopentadiene using slow distillation and keeping the. This colorless liquid has a strong and unpleasant odor. Gas phase cracking of dicyclopentadiene to produce. Cracking, in petroleum refining, the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts. At the boiling point of dicyclopentadiene, equilibration with the. The sensitivity is determined by the slope of the calibration curve see figure 3. Also, when cooling a piece of equipment that contains the hot bottoms from the distillation or. Process for producing cyclopentadiene and its homologues. The thermodynamic parameters of this process have been measured. Abstract cyclopentadiene and dicyclopentadiene, which occur as byproducts in the steam cracking process in ethylene plants, are the major.
May react exothermically with reducing agents to release hydrogen gas. Other procedures i found attached nitrogen to the setup. Cyclopentadiene dimer chemical reference number cas. 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. 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. To obtain cyclopentadiene monomer, commercial dicyclopentadiene is cracked by heating to 180 c. In this event a periodic increase in the variac setting may be required. Dicyclopentadiene should never be distilled to dryness since there is danger of explosion if peroxides are present. The resulting vapors are fractionated to remove refluxing uncracked dimer and.
Experimental procedure cracking dicyclopentadiene to obtain cyclopentadiene as discussed in the introduction, cyclopentadiene must be obtained by cracking dicyclopentadiene. During this time the rate of cracking may decrease. The reaction kinetics of cyclopentadiene dimerization using. Cracking of petroleum yields light oils corresponding to gasoline, middlerange oils used in diesel fuel, residual heavy oils, a solid carbonaceous product known as coke, and such gases as methane, ethane. Working with hazardous chemicals organic syntheses. Dicyclopentadiene dcpd 3a,4,7,7atetrahydo4,7methano1hindene c10h12 general dicyclopentadiene or dcpd is the dimer of cyclopentadiene cpd formed by a dielsalder addition. Cyclopentadiene can be further purified by sequential dimerizations under carefully controlled slow heat soaking and subsequent monomerizations. The purpose of this experiment was to demonstrate the formation of sixmembered rings by cycloaddition, also known as a dielsalder reaction. In a cycloaddition reaction, a 1,3diene reacts with an alkene, or dienophile, to produce a sixmembered ring. Cyclopentadiene and dicyclopentadiene cheung major. Dicyclopentadiene is primarily used in unsaturated polyester resins and also used in inks, adhesives, and paints.
How would you interpret efficient watercooled condenser. C and then collected by fractional distillation process within an icecooled receiver. Catalytic enantioselective 1,4iodofunctionalizations of conjugated dienes. Dcpd is a cyclic hydrocarbon that appears as colorless crystals, soluble in ethanol, diethyl ether, and acetic acid. Industrial process economics reports about dicyclopentadiene dcpd dicyclopentadiene dcpd is a white crystalline solid with a camphorlike odor. Its a colorless, waxy, flammable solid or liquid, with a camphorlike odor.
This procedure largely avoids the codimerization of. At room temperature, it is a clear light yellow color liquid with an acrid odor. This invention relates to the thermal depolymerization or cracking of dicyclopentadiene and its homologues. A reactive distillation process was developed for cracking dicyclopentadiene dcpd to produce cyclo pentadiene cpd. At the boiling point of dicyclopentadiene, equilibration with the monomer is rapid. Large quantities are coproduced in the steam cracking of naphtha and gas oils to ethylene. Dicyclopentadiene is a peroxide forming chemical pfc. Recently, as a process for manufacturing cyclopentadiene resinshaped articles, an attention has been given to reaction injection molding rim.
I recently did a distillation of dicyclopentadiene bp 166 c to get cyclopentadiene bp 40 c. Cyclopentadiene production is usually not distinguished from dicyclopentadiene since they are interconverted. Cyclopentadiene dimer, 4,7 methano 3a,4,7,7a tetrahydroindene, dicyclopentadiene. Can undergo exothermic polymierization reactions in the. This is achieved by using the fractional distillation set up shown in the photo. The resulting vapors are fractionated to remove refluxing uncracked dimer and entrained liquid. This procedure largely avoids the codimerization of cyclopentadiene with residual unsaturated c5 impurities, allowing the latter to be removed from dicyclopentadiene by stripping. A commercial procedure entails vapor phase cracking at gree. The dicyclopentadiene dimer c 10 h 12 is broken down cracked to the monomer c 5 h 6 cp. Preparation of cyclopentadiene from dicyclopentadiene. When pure cyclopentadiene is stored it also undergoes a dielsalder. Cracking tube 2 is a stainless tube with an internal diamer.
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. They are obtained from coal tar about 1020 gtonne and by steam cracking of naphtha about 14 kgtonne. The reaction kinetics of cyclopentadiene dimerization. Solventfree dielsalder reactions of in situ generated. Dielsalder reaction figure 1 fractional distillation set up figure one demonstrates the fractional distillation set up which was used to crack dicyclopentadiene. The setup as instructed by my supervisor consisted of a simple watercooled liebig condenser. A typical procedure involves the treatment of a 1aminoethylsubstituted butadiene with maleic anhydride at 0 degc to room temperature for 20 minutes under low.
1514 224 1388 1265 323 485 1446 1199 767 991 1203 386 24 1490 165 1183 92 1048 1461 273 5 1260 1396 174 1079 66 1351 539