Dicyclopentadiene polymerized

Figure 2. Change in stress-strain behavior with time, with dicyclopentadiene polymerized sulfur...

Cycloaliphatic Diene CPD—DCPD. Cycloatiphatic diene-based hydrocarbon resias are typically produced from the thermal or catalytic polymerization of cyclopeatadieae (CPD) and dicyclopentadiene (DCPD). Upon controlled heating, CPD may be dimerized to DCPD or cracked back to the monomer. The heat of cracking for DCPD is 24.6 kJ / mol (5.88 kcal/mol). In steam cracking processes, CPD is removed from C-5 and... 

Gyclopentadiene/Dicyclopentadiene-Based Petroleum Resins. 1,3-Cyclopentadiene (CPD) is just one of the numerous compounds produced by the steam cracking of petroleum distillates. Due to the fact that DCPD is polymerized relatively easily under thermal conditions without added catalyst, resins produced from cycloaHphatic dienes have become a significant focus of the hydrocarbon resin industry. 

Cyclic Polyolefins (GPO) and Gycloolefin Copolymers (GOG). Japanese and European companies are developing amorphous cycHc polyolefins as substrate materials for optical data storage (213—217). The materials are based on dicyclopentadiene and/or tetracyclododecene (10), where R = H, alkyl, or COOCH. Products are formed by Ziegler-Natta polymerization with addition of ethylene or propylene (11) or so-called metathesis polymerization and hydrogenation (12), (101,216). These products may stiU contain about 10% of the dicycHc stmcture (216). 

In the process of thermal dimerization at elevated temperatures, significant polymer is formed resulting in seriously decreased yields of dimer. Dinitrocresol has been shown to be one of the few effective inhibitors of this thermal polymerization. In the processing of streams, thermal dimerization to convert 1,3-cyclopentadiene to dicyclopentadiene is a common step. Isoprene undergoes significant dimerization and codimerization under the process conditions. 

Dicyclopentadiene is also polymerized with tungsten-based catalysts. Because the polymerization reaction produces heavily cross-Unked resins, the polymers are manufactured in a reaction injection mol ding (RIM) process, in which all catalyst components and resin modifiers are slurried in two batches of the monomer. The first batch contains the catalyst (a mixture of WCl and WOCl, nonylphenol, acetylacetone, additives, and fillers the second batch contains the co-catalyst (a combination of an alkyl aluminum compound and a Lewis base such as ether), antioxidants, and elastomeric fillers (qv) for better moldabihty (50). Mixing two Uquids in a mold results in a rapid polymerization reaction. Its rate is controlled by the ratio between the co-catalyst and the Lewis base. Depending on the catalyst composition, solidification time of the reaction mixture can vary from two seconds to an hour. Similar catalyst systems are used for polymerization of norbomene and for norbomene copolymerization with ethyhdenenorbomene. 

Ring-Opening Metathesis Polymerization. Several new titanacyclobutanes have been shown to initiate living ring-opening metathesis polymerization (ROMP) systems. These have been used to make diblock and triblock copolymers of norbomene [498-66-8] (N) and its derivatives (eg, dicyclopentadiene [77-73-6] (D)) (Fig. 2) (41). 

Hydrocarbon Resins. Dicyclopentadiene is widely used in both cmde and purified form as a monomer in hydrocarbon resin production (see Hydrocarbon resins). These resins, produced in both the United States and Europe, are polymerized from concentrated DCPD streams or from the previously mentioned resin oils. The DCPD-containing stream may be polymerized with Friedel-Crafts (qv) (53) catalysts either alone or in admixture with the resin oil (54—55), or with aUphatic olefins and diolefins (56) or by thermal polymerization (57—59). 

Elastomers. Ethylene—propylene terpolymer (diene monomer) elastomers (EPDM) use a variety of third monomers during polymerization (see Elastomers, ethyiene-propylene-diene rubber). Ethyhdenenorbomene (ENB) is the most important of these monomers and requires dicyclopentadiene as a precursor. ENB is synthesized in a two step preparation, ie, a Diels-Alder reaction of CPD (via cracking of DCPD) with butadiene to yield 5-vinylbicyclo[2.2.1]-hept-2-ene [3048-64-4] (7) where the external double bond is then isomerized catalyticaHy toward the ring yielding 5-ethyhdenebicyclo[2.2.1]-hept-2-ene [16219-75-3] (ENB) (8) (60). 

Poly(dicyclopentadiene). The development of polydicyclopentadiene [25038-78-2] for reaction injection molding is an area which has generated much interest. The polyDCPD is obtained via metathesis polymerization of high purity (usually greater than 98%) DCPD. Excellent reviews (61—62) of the chemistry and properties of polyDCPD have been pubHshed. The patent Hterature of polyDCPD synthesis, catalysts, modifiers, and appHcations is dominated by Hercules (44 patents) and B. F. Goodrich (43 patents) in the U.S. Other participants are Orkem, SheU, Nippon Zeon, and Teijin. 

Several different companies have greened various steps of the process. In VNB production by-products come from competing Diels-Alder reactions and polymerization, largely of cyclopentadiene. The reaction is usually carried out in a continuous tube reactor, but this results in fouling, due to polymerization, at the front end, where the dicyclopentadiene is cracked to cyclopentadiene at temperatures over 175 °C. Whilst fouling does not have a very significant effect on yield, over time it builds up. 

The first documented example of the living ROMP of a cycloolefin was the polymerization of norbornene using titanacyclobutane complexes such as (207) 510-512 Subsequent studies described the synthesis of di- and tri-block copolymers of norbornenes and dicyclopentadiene.513 However, functionalized monomers are generally incompatible with the highly electrophilic d° metal center. 

End groups, in PVC polymerization, 25 666 End-group spectral lengths, 20 507 correlation equations for, 20 508t Endo-aerators, 26 162-170 em/o-dicyclopentadiene (DCPD), 26 946-947 Endoenzymes, 10 255 End-of-life (EOL) electronics, recycling, 21 456... 

Liquid-molding resins, based on poly(dicyclopentadiene), 20 432 Liquid monomer phase, in PVC polymerization, 25 667 Liquid NaK alloy, 20 603. See also NaK entries... 

D. Schaubroeck, S. Brughmans, C. Vercaemst, J. Schaubroeck and F. Verpoort, Qualitative FT-Raman investigation of the ring opening metathesis polymerization of dicyclopentadiene, J. Mol. Catal. A Chem., 254, 180-185 (2006). 

Hydrocarbon resins comprise a range of low-molecular-weight products (M < 3000) used as adhesives, hot-melt coatings, tackifying agents, inks, and additives in rubber. These include products based on monomers derived from petroleum as well as plant sources. The petroleum-derived products include polymers produced from various alkenes, isoprene, piperylene, styrene, a-methylstyrene, vinyltuolene, and dicyclopentadiene. The plant-derived products include polyterpenes obtained by the polymerization of dipentene, limonene,... 

Figure 1.7 Ring opening metathesis polymerization of dicyclopentadiene using transition metal catalysts...

Dicyclopentadiene reacts with rhenium(III) chloride to give the polymeric complex [ReCl2(CioII,2)2] , and with triphenylphosphinerhe-nium(III) chloride to give the complex [ReCl(CioHi2)2(PPh3)] (49). The structures of these complexes are unknown. 

Curable poly(dicyclopentadiene), (V), was prepared by Konze et al. (4) using ring-opening metathesis polymerization with tungsten oxychloride and diallyldimethylsilane. 

The molybdenum-based catalyst MoOCl2(t-BuO)2 has been used to copolymerize norbornene and dicyclopentadiene (20). The polymeric product exhibits a single peak in gel permeation chromatography. 

C.S. Woodson, Jr. and R.H. Grubbs, Polymeric composites including dicyclopentadiene and related monomers, US Patent 6310121, assigned to Cymetech, LLC (Huntsville, TX), October 30, 2001. 

---