APPLICATIONS OF THE OLEFIN METATHESIS REACTION TO INDUSTRIAL PROCESSES

F. LEFEBVRE Laboratoire LCOMS, UMR CNRS-CPE 9986, 43 Bd du 11 Novembre 1918,69626 Villeurbanne Cedex, France

1. Introduction

The industrial applications of the olefin metathesis reaction are relatively recent although this reaction was observed about 50 years ago. Streck described in details the historical development of this reaction in his review in a book of the same series [1]. He gave also interesting data on the industrial processes in refs. [2] and [3]. More recently, Ivin and Mol, in their classical book on olefin metathesis, have also developped this field in a special chapter [4]. The idea of olefin disproportionation was first proposed by Robert Banks at Phillips [5], who had observed traces of pentenes and propene in the reaction mixture after passing isobutane and butenes through a bed filled with molybdenum carbonyl supported on alumina. The Ring Opening Metathesis Polymerization was found by the Natta group at Montedison [6, 7]. Many groups studied this reaction and its mechanism was proposed by Chauvin [8], years before the isolation of the first carbene. What is important to know is that the development of these industrial processes was strongly related to economical and/or special local conditions. This could be the transformation of sideproducts or the obtaining compounds with a higher added value. We have separated the industrial applications into two groups, depending on the resulting product, an acyclic olefin or a polymer. Up to now, the third class of applications, the ring closing metathesis reaction, has not been applied industrially, despite some interesting results were obtained on the laboratory scale.

2. Processes for the Production of Acyclic Olefins

2.1. THE TRIOLEFIN PROCESS AND RELATED PROCESSES

2.1.1. Thetriolefinprocess Historically, the triolefin process, developed by Phillips, was the first industrial application of olefin metathesis [9 - II]. It involved the preparation of high purity ethylene and but-2-ene from propene:

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E. Khosravi and T. Szymanska-Buzar (eds.), Ring Opening Metathesis Polymerisation and Related Chemistry, 247-261. © 2002 Kluwer Academic Publishers.

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It was developed in order to valorize the C3 fraction of a local naphtha cracker. Shawinigan Chemicals Inc. Used this process in thewir plant near Montreal (at Varennes) in Canada from 1966 to 1972. The plant had a capacity of 50000 tons of feedstock per year. The catalyst used was tungsten oxide supported on silica and doped with sodium to prevent the double bond shift reaction of but-2-ene (which should decrease the selectivity). The operating temperature was between 370 and 450°C and the. conversion (40 - 43%) corresponded to near equilibrium conditions. The selectivity towards ethylene and but-2-ene was very high (> 95%). In addition, instead of pure propene, it was possible to use directly the C3 fraction (propane + propene) of the naphtha cracker. A change of the economic data and a higher demand of propene led to the closure of the plant in 1972. However, as it was relatively simple (see Figure 1), it could be restarted easily, probably not for obtaining but-2-ene but for the production of high purity but-l-ene, after treatment with an isomerization catalyst. Indeed, but-l-ene can be used as a comonomer in polyethylene synthesis.

Propene

Propane

C4 ....

Prop>ne

Figure 1 : Scheme of the triolefin plant

2.1.2. The reverse triolefinprocess

C4

C5+

Different market conditions rendered attractive the use of the process in the reverse direction to produce polymerization grade propene from ethylene and but-2-ene. In this process, but-2-ene can be obtained directly from the C4 fraction of a naphthta cracker or by dimerization of ethylene. In 1985, the Lyondell Petrochemical Co. started to operate a plant at Channelview (Texas, U.S.A.), for the production of 135000 tons of propene per year. In this process, part of the ethylene formed by cracking units of ethane is dimerized to but-2-ene using a homogeneous nickel catalyst developed by Phillips. This but-2-ene reacts with the rest of ethylene, on the classical Phillips catalyst, to produce propene.

2.1.3. The IFP Meta-4 process The Institut Fran~ais du Petrole and the Chinese Petroleum Co. at Taiwan developped a new process, called Meta-4 [12] for the preparation of propene from ethylene and butene. This process was proposed to valorize the C4 fraction of steam-cracking after

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extraction or semi-hydrogenation of the butadiene and transformation of the isobutene into poly-isobutene or methyl tertiobutyl ether. It could also allow the propene/ethylene ratio to be increased in the products of the steam-cracking without changing the cracking conditions. The catalyst was rhenium oxide on alumina, allowing the reaction to proceed at low temperature (35°C). The use of pressure (60 bar) allowed it to proceed in the liquid phase. A pilot plant was built in Taiwan and operated from 1988 to 1990, with a capacity of 15kg of propene per hour. The process (Figure 2) can be seen as a semi-continuous counter current contact between the reactant mixture and the catalyst. When the system operates, the stream enters the bottom of the reactor and goes out by the top. However, the catalyst deactivates and when it descends through the reactor, it becomes less and less active and must be regenerated. For this purpose, a small percentage of the catalyst is taken periodically from the bottom of the reactor and transferred into the regenerator. The regenerated catalyst is then returned to the top of the reactor. The plant is completed by two columns where the reactor effluents are separated. The remaining ethylene and but-2-ene are recycled.

,...-______ C2

CJ

c~

Figure 2 : Scheme of the IFF Meta-4 process

Up to now, this process has not been applied industrially, even if some industrialist are interested in introducing such a metathesis step in their refining process. The main problem is the cost of the catalyst which does not render the process competitive with the classical Phillips system. A decrease of the rhenium loading by a factor 2 should allow it to be more attractive. Another problem is that the reactants must have a high purity, in contrast to the classical process which is less sensitive to contaminants, due to the high reaction temperature.

2.2. THE NEOHEXENE PROCESS

At the beginning of the sixties, laboratory studies showed that diisobutene (2,4,4-trimethyl pent-2-ene) could be cleaved with ethylene over a classical metathesis catalyst to produce neohexene and isobutene [13 - 15].

250

/\Y + .. +

Neohexene can be a very important intermediate in the manufacture of a synthetic musk. Hence the market for neohexene grew rapidly. Phillips started the industrial development in 1969 with a small pilot plant producing 20kg of neohexene per year and which worked during three years and produced 3 tons of neohexene which were sold. As the demand increased, a larger unit, with four times the capacity of the smaller pilot, was then constructed. As the demand for neohexene continued to increase ( from 90 tons in 1973 to 270 tons in 1979), a commercial unit was constructed in 1980. It is located at the Phillips petrochemical complex near Houston (Texas, U.S.A.) and has a capacity of 1400 tons per year.

Dimcrizalion ,..=.;==:.;;.::..-E-Ih-,yl-en-e---- Isobulene

Noohc"c e

Heavies

Figure 3 : Scheme of the neohexene plant

From a practical point of view, commercial diisobutene is a mixture of 2,4,4-trimethyl pent-2-ene, used in the cross-metathesis reaction, and of 2,4,4-trimethyl pent-l-ene (not modified by the metathesis reaction), in a relatively large amount (20 to 25%). In order to valorize the process, it is necessary to use commercial diisobutene and so to convert the terminal non useful olefin into the internal useful one. This can be done by mixing the metathesis catalyst (W03/Si02) with an isomerization catalyst (typically magnesia) together in the reactor. Typically, with a 1 : 3 mixture of WOiSi02 and MgO, at 370°C, under a 30 bar pressure and with a ethylene to diisobutene ratio of 2. A conversion of 65% of diisobutene is achieved with a neohexene selectivity around 85%. A simplified scheme of the plant is shown on Figure 3. Commercial diisobutene entering the plant is first fractionated to remove an oxidation inhibitor which poisons the dual catalyst. The recycled diisobutene is also fractionated to remove « heavies» (typically C9). The fractionated diisobutene, along with the ethylene stream, enters the top of the reactor containing the dual catalyst. The ethylene stream consists of « make­up » and « recycle » ethylene and is passed through a compressor to obtain the desired reaction pressure. The reaction temperature is easy to maintain as the reaction is only

251

slightly exothermic. The reactor effluents are cooled and the pressure is decreased. They are then split into a gas fraction (containing mainly ethylene and a few entrained liquid) and a liquid part (containing mainly isobutene, neohexene and diisobutene) which is further fractionated. Diisobutene i's recycled directly while isobutene is recycled via its transformation into diisobutene in a dimerization reactor. During a typical process cycle, the diisobutene conversion starts at about 75% and gradually declines. When the conversion reaches 50~, the catalyst system is regenerated using an air-inert gas mixture to control the temperature of the coke burn­off. Throughout the process, the selectivity to neohexene remains constant at c.a. 85%. As said above, the main application of neohexene is the synthesis of musk perfume components, in two steps. The first step is the alkylation of p-cymene by neohexene and the second a reaction with acetyl chloride:

o

}=o CI

Other applications such as epoxidation with H20 2, alkylation with benzene or amination were also proposed but have not been yet applied industrially.

2.3. THE FEAST (FURTHER EXPLOITATION OF ADVANCED TECHNOLOGY) PROCESS

This process allows the synthesis of a,w-diolefins by cross-metathesis of cycloolefins with ethylene. The reaction was first studied by Phillips who produced multi-tons of 1,5-hexadiene [13]. Feedstocks for this process were two commercially available butadiene derivatives, cyclooctadiene and cyclododeCairiene.

o 1,5.9-decatriene

1.5-hexadiene

1.5-hexadiene

252

The reaction was made on the classical Phillips catalyst and, by use of an excess of ethylene, high conversions (> 99 %) and selectivities (> 65 %) to 1,5-hexadiene could be achieved. Phillips also proposed a route to 1,9-decadiene by homogeneous hydrogenation of cyclooctadiene to cyclooctene and then cross-metathesis with ethylene over WOiSi02 (yield 75% for a conversion of 90%).

0-"' 0- 1 ,9·decadiene

Shell developed a process, called FEAST [16], using these reactions but with a different catalyst, promoted rhenium oxide on alumina. This catalyst allowed the reaction to proceed under very mild conditions (0 to 20°e, I or 2 bar). A commercial plant, allowing the production of 3 000 tons per year of diolefins was opened in 1987 at the Etang de Berre (France). It has been closed some years ago, due to the lack of the market.

2.4. THE SHOP (SHELL HIGHER OLEFIN PROCESS) PROCESS

To date, the largest scale industrial process containing a metathesis reaction is the SHOP process, developped by Shell, for the preparation of detergent-range alkenes from ethylene [17, 18].

CHr(CH2hn.rCH=CH2 n=5-lO

The entire process is schematized on Figure 4. In the first step, ethylene is oligomerized in the presence of a homogeneous nickel phosphine catalyst. This catalyst is a nickel hydride generated by reduction of a nickel salt in the presence of a chelating ligand such as diphenylphosphinobenzoic acid or by reaction of nickel(O) with a phosphorus ylide.

n CH2--CHz cat. 100 QC, 80 bars

Cat =

CHr(CH2)zn.rCH=CH2

Ph Ph \....... PPh

CP,\ / 3

NI

/ "H o

n = 2 - 20

Such a catalyst is allowed to react with ethylene in a glycol solvent such as 1,4-butanediol at about lOO°C and 80 bars. The pressure is required to attain a high linearity. A rapid reaction occurs, leading to a mixture of a-olefins from C4 to C40 with a Schulz-Flory distribution (40% in the C4 - C8 range, 40% in the CIO - CI8 range and

253

20% above). The olefins are immiscible in the catalyst containing glycol layer and are separated by decantation. After washing the olefin layer with additional glycol to remove catalyst traces, the catalyst can be reused. Originally, the CIO - CIS fraction of the olefins was the most marketable but now octene and hexene are valuable products and so the C6 - CIS fraction is separated and can be further fractionated into individual components.

EJ----+ I ~.,.~ I ---+ [ CII - Czo I l

········1 <C6 +>C20

I~····~l ~

PL...-__ '--/_~ __ '---J"

I CII - C20 I Figure 4 : Scheme of the SHOP process

The remaining lighter ( < C6) and heavier ( > CIS) olefins undergo, in a second step, double bond isomerization over a potassium metal based catalyst to an equilibrium mixture of internal olefins. This second step proceeds at 100DC and at 10 bars. In a third step, the low- and high-boiling internal olefins are cross-metathesized over a heterogeneous catalyst such as Mo03 or a cobalt molybdate supported on alumina. Additional ethylene can be added at this moment for optimization of the process. Due to the prevalence of reactions between a low and a high-boiling olefin, most of the product is in the useful range ("" 15% in the Cll - C14 range). The remaining is recycled. The final product consists of more than 95% linear alkenes with c.a. 3% branched olefins. Finally, these olefins can be converted into terminal alcohols by hydroformylation with a cobalt catalyst. Shell began large-scale production (200000 tons per year) in 1979 in Geismar (Louisiana, U.S.A.) and the capacity was increased to 590 000 tons per year in 1989. A second plant was also built in 1987 in Stanlow (U.K.) with a capacity of 270000 tons per year.

2.5. NON COMMERCIAL PROCESSES

2.5.1. Synthesis of styrene from toluene This process had been studied by Monsanto [19] and Gulf [20, 21]. Its advantage should be to use toluene instead of benzene. In a first step, toluene is converted into stilbene by oxidative coupling (dehydrodimerization) at 600DC over lead oxide supported on alumina. The oxygen used in the reaction comes from the lead oxide (stoichiometric reaction).

254

~. Dehydrodimerization Metathesis

It is then necessary to periodically regenerate lead oxide by reaction with oxygen. In the second step, stilbene is cross-metathesized with ethylene over a classical W03/Si02

based catalyst. In order to prevent polymerization of styrene, this second reaction is also made at high temperature ( > 400°C). Even if this process seems attractive, it presents some problems which render it to be improved before commercial application. The main one is the high amount of oxidant which is required (one mole of lead per mole of toluene). The second problem is the presence, in stilbene, of oxygenated compounds which are poisons for the metathesis catalyst.

2.5.2. The isoamylene process Various industrial companies have developed a process for the production of isoamylene (2-methyl but-2-ene), which is a precursor of isoprene (obtained by oxidative dehydrogenation). It can be produced by cross-metathesis of isobutene with but-2-ene or propene:

+~

+~ The process has been developed by Phitlips at the pilot stage [22]. The feed entering the reactor contained a mixture of isobutene (50%), propene and but-2-ene. The catalyst was the classical Phillips system, W03/Si02.

However the process has never been commercialized, due to economic changes. Indeed, isobutene is now mostly used for the manufacture of methyl tertiobutyl ether, which is used as additive to gasoline.

2.5.3. Synthesis of2,2,3-trimethyl pentane from propene 2,2,3-trimethyl pentane is an additive to gasoline of which it increases the octane number. It has been proposed to synthesize it from propene, in two steps [23, 24]. In the first step, propene is metathesized into but-2-ene and ethylene, by the classical Phillips triolefin process:

But-2-ene is then alkylated with isobutane, leading to the target product:

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As for the classical triolefin process, the higher demand of propene has prevented the development of this process.

2.5.4. Synthesis of higher olefins from propene This process can be understood as a succession of metathesis and isomerization reactions [25]. In a first step, propene is metathesized into ethylene and but-2-ene :

But-2-ene is then isomerized into but-I-ene:

But-I-ene is allowed to cross-metathesize with propene, leading to pent-2-ene which is further isomerized into pent-I-ene. The sequence of these two reactions, metathesis and isomerization, is repeated as many times as necessary:

CHr(CH2)n-CH=CH2 + CH3-CH=CH2 .. CH3

CHr (CH2)n+I-CH=CHz

The main problem of this process, in addition to the fact that it uses propene as a reagent, is that increasing the carbon length by one carbon atom requires one propene molecule and forms one ethylene molecule. This does not render it competitive vs. the SHOP process, for example.

2.5.5. Redistribution of alkanes This process could be used for the modification of a distribution of alkanes [26]. It comprises three steps. In a first step, the alkanes are dehydrogenated over a classical catalyst such as PtlAIz03. The resulting alkenes undergo then a metathesis reaction, over a classical W03/Si02 catalyst, allowing the redistribution of chain lengths. Finally, alkenes are rehydrogenated into alkanes over PtlAI20 3•

3. Processes for the Production of Polymers

Up to now, all processes developed industrially for the production of polymers by olefin metathesis involve ring opening metathesis polymerization of cycloalkenes.

256

n u 3.1. POLYMERIZATION OF CYCLOPENTENE

Cyc10pentene is a relatively inexpensive compound which is obtained by thermal cracking of dicyc10pentadiene and further hydrogenation. Its polymerization has been widely studied:

ROMP of cyc10pentene is achieved easily with conventional metathesis catalysts such as WClJJjtAlClz/ROH or W03/AIz03. The Institut Fram;ais du Petrole developed also highly active catalysts (substrate to catalyst ratio of 500000) based on Fischer type carbenes ((CO)sW=C(OEt)Ph + TiCI4) for this reaction [27]. The polymer properties were reported to be excellent (strength higher to other synthetic rubbers, high modulus and resilience, excellent abrasion and resistance, complete compatibility with other elastomers [28]. Industrialist decided then to use this polymer in tyres. Unfortunately, the tests were disastrous, the rubber crumbling and disintegrating at the shoulders. For Breslow, this was due to a depolymerization process. Traces of WOiAI20 3, used for the polymerization, remained in the rubber and as the shoulders are the hottest part of the tyre, some depolymerization could occur [29]. More recently, it has been shown that, in fact, this was due to a phase transition of the polymer [30]. But, to date, this has prevented the commercial application of this polymer.

3.2. POLYMERIZATION OF CYCLOOCTENE (VESTENAMER®)

The ring opening polymerization of cyclooctene was marketed by Chemische Werke Hiils in 1982. The plant was implanted in Marl (Germany) and has now a capacity of 12000 tons per year.

~n poly-octenamer

The catalyst is the classical Calderon system, WClJJjtAlClz/EtOH. The resulting polymers are sold under the tradename Vestenamer®. Most of the production corresponds to Vestenamer 8012. This polymer contains 80% of trans double bonds and has a viscosity of 120cm3g- 1 (0.1 % solution in toluene at 25°C), explaining the acronym «Vestenamer 8012 » [2, 31]. This polymer has also a low molecular weight

257

(Mw = 60000 to 80000) and a high crystallinity (c.a. 33%). At room temperature, it is hard and it has an exceptionally high viscosity. Above 60°C, it becomes a fluid with a honey-like consistency (its melting point is 55°C). The hardness at room temperature is due to the high crystallinity while the fluidity at high temperature is due to the low molecular weight. It is especially suitable for use in blends with other rubbers since the above properties are carried over, to some extent, into the blends, which become stiffer at room temperature and flow more easily at 60°C. Generally, 10 to 30% of Vestenamer are sufficient to confer these technical advantages.

3.3. POLYMERIZATION OF NORBORNENE (NORSOREX®)

CdF Chimie commercialized in 1976 polynorbornene under the tradename Norsorex®. The plant was located in Carling (France) and had a capacity of 5000 tons of polynorbornene per year [32].

n -'~n polynorbornene

The monomer is made by the Diels-Alder reaction of dicyciopentadiene with ethylene. The catalyst for ROMP is ruthenium chloride in butanol. The process is relatively simple as the two liquids (ruthenium chloride in butanol and norbornene) are directly mixed in the extruder, in air. The norbornene to ruthenium ratio is very high (c.a. 25000) and the conversion reaches 50%. As the process operates in air, a small amount of norbornene is oxidized into epoxynorbornane (the epoxide to ruthenium ratio is c.a. 5) which can accelerate the polymerization. Indeed, mechanistic studies have shown that the catalytic reaction passes through a ruthenium hydride (formed by substitution of chlorine by butoxy ligands and further ~-H abstraction) or through a ruthenium oxametallacyciobutane (formed by reaction of the ruthenium complex with epoxynorbornane) [33]. The polymer has a very high molecular weight (more than 2000000) and a high trans content ( more than 80%). It can adsorb up to seven parts of extending oils or esters plasticizers. The vulcanized product has important specialty applications, particularly for vibration damping.

3.4. POLYMERIZATION OF DICYCLOPENTADIENE (METTON®, TELENE®)

The cheapness of dicyciopentadiene (DCPD), obtained as a byproduct from the cracking of oil, makes it an attractive candidate for the production of materials by metathesis polymerization. Its ROMP has been extensively studied and two companies, BFGoodrich and Hercules, have commercialized the corresponding polymer under the tradenames Telene® and Metton® respectively [34, 35]. Recently, a part of BFGoodrich and APT (Advanced Polymer Technologies) formed a joint venture to produce some related products, especially poly-DCPD. This company has

258

become the largest supplier of poly-DCPD in the United States and it can manufacture large and complex parts, weighing up to 500 kg. On the other hand, Hercules has a plant in Deer Park (Texas), with a capacity of 13600 tons of poly-DCPD per year. DCPD has two double bonds which can react by ROMP. However, the norbornene­type double bond can react much more easily than the other double bond, which undergoes only partial ring opening polymerization, responsible of the cross-linking. The structure of the polymer can then be shown as below:

For example, in Metton there is one cross-linkage for five monomer units. The cross­linking will be responsible for most properties of poly-DCPD and it can be increased by various ways such as the addition of a cationic initiator or of a comonomer (the trimer of cyclopentadiene is used in Telene). The cis/trans ratio of the double bonds can vary, depending on the catalysts. For Metton, it is usually about 3/2. Depending on the company, various catalytic systems are used: Hercules used tungsten aryloxide complexes with aluminium or tin alkyls [36], while BFGoodrich uses a trialkyloctamolybdate with also an aluminium alkyl. Shell developped a catalyst based on the WClJdiisopropyiphenol1R3SnH system [37]. The most interesting feature of the industrial process is that it uses the RIM (Reaction Injection Molding) technology. A scheme of the RIM process is given on Figure 5. Two streams arrive in a mixing chamber where they are mixed, before injection into the preheated mold. The first mold contains the catalyst (for example the tungsten aryloxide complex) while the second contains the cocatalyst (typically an alkyl aluminium chloride). The DCPD is in one or the two streams. The polymerization reaction occurs in the mould and the heat of reaction raises the temperature up to 150°C in a few minutes. The main problem is to control the induction period to prevent polymerization in the mixing chamber. This can be achieved by adding a Lewis base (acetylacetone, benzophenone, dibutyl ether) which will act as a moderator. Other problems are that in most cases the conversion is not complete necessitating unconverted DCPD to be removed and that pure DCPD is a solid at room temperature and so the stream must be heated. The RIM process has great advantages. Indeed, it does not necessitate a high cost equipment, due to the low molding pressure, and it allows the manufacture of large and complex parts. It operates in air, without purge. One advantage of working in such conditions is that the surface of poly-DCPD is oxidized, allowing an easy painting of the resulting solids.

259

DCPD DCPD Catalyst Cocatalyst

y-Moderator

Polymerization

Figure 5 : Scheme of a RIM process

3.5. POLYMERIZATION OF NORBORNENE DERIVATIVES (ZEONEX®)

Recently, Nippon Zeon developped a process for the synthesis of polymers displaying interesting properties and commercialized under the tradename Zeonex [38-44]. These materials are obtained by ring opening polymerization of norbornene type derivatives followed by a partial or total hydrogenation of the double bonds. The monomer contains three to five cycles.

1 'R R

n = 0 - 2 ; R, R' = H, alkyl The catalyst is a typical norbornene polymerization homogeneous catalyst, for example a tungsten halide with an organoaluminium compound and a tertiary amine. The hydrogenation step is made with a classical heterogeneous catalyst such as palladium on carbon. The molecular weight of zeonex varies between 20000 and 500000, depending on the monomer. It is amorphous with a high glass transition temperature (c.a. 140°C). As it does not contain any polar group, it provides low water absorption and moisture permeability. In addition, it is colorless and transparent. All these properties make it ideal for applications such as optical disks and plastic lenses.

4. Conclusion

This overview has given industrial applications of the olefin metathesis reaction. If most commercial applications have been listed, only some of the non-commercialized ones were given but even so some conclusions can be drawn: (i) Up to now all industrial applications are limited to unfunctional olefins, as functional groups deactivate the metathesis catalysts. Search for more tolerant catalysts, such as ruthenium, could overcome this problem. (ii) The recently developed alkylidene catalysts suffer from a main disadvantage, their price, due to the difficulty of their synthesis which prevents also their easy recycling.

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They could be used only for applications where these two parameters are not a problem, typically in the domain of pharmaceuticals. In this domain, the main application of olefin metathesis should be the ring closing reaction. (iii) In the domain of polymers, applications should be searched for in specialty chemicals, probably in close contact with the other polymerization processes. As alkylidene catalysts are often used, high turnover numbers should be needed.

5. References

1. Streck, R. (1990), in Y. Imamoglu, B. Ziimreoglu-Karan and A.1. Amass (eds.), Olefin Metathesis and Polymerization Catalysts, NATO AS! Series Vol. 326, Kluwer Academic Publishers, Dordrecht, pp. 439-455.

2. Streck, R. (1990), in Y. Imamoglu, B. Ziimreoglu-Karan and A.J. Amass (eds.), Olefin Metathesis and Polymerization Catalysts, NATO AS! Series Vol. 326, Kluwer Academic Publishers, Dordrecht, pp.457-488.

3. Streck, R. (1990), in Y. Imamoglu, B. Ziimreoglu-Karan and A.J. Amass (eds.), Olefin Metathesis and Polymerization Catalysts, NATO AS! Series Vol. 326, Kluwer Academic Publishers, Dordrecht, pp.489-515.

4. !vin, K.J. and Mol, J.e. (1997), Olefin Metathesis and Metathesis Polymerization, Academic Press, San Diego.

5. Banks, RL. (1986), ChemTech 16,112. 6. Dall' Asta, G. and Mazzanti, G. (1963), Makromol. Chem. 61, 178. 7. Dall' Asta, G. (1968),1. Polym. Sci. A-i 6,2397. 8. Herisson, J.L. and Chauvin, Y. (1970), Makromol. Chem. 141, 161. 9. Peters, E.F. and Evering, B.L. (1958), US. pat. 2963471. 10. Banks, R.L. and Bailey, G.e. (1964), indo Eng. Chem., Prod. Res. Div. 3,170. II. Banks, RL. (1979), ChemTech 9, 494. 12. Amigues. P., Chauvin, Y., Commereuc, D., Lai, e.e., Liu, Y.H. and Pan, J.M. (1990), Hydrocarbon

Process. 83,79. 13. Banks, R.L., Banasiak, D.S., Hudson, P.S. and Norell, J.R. (1982) Specialty chemicals via olefin

metathesis, I. Mol. Catal. 15,21-33. 14. Reusser, R.E. and Crain, D.L. (1974), US. pat. 3 729524. 15. Montgomery, D.P (1972), Us. pat. 3707579. 16. Chaumont, P. and John, e.S. (1988), 1. Mol. Catal. 46, 317. 17. Freitas, E.R. and Gum, e.R. (1979), Chem. Eng. Progr., 75. 18. Sherwood, M. (1982), Chem. indo (London), 994. 19. Montgomery, P.D., Moore, R.N. and Knox, W.R (1976), US. pat. 3 965 206. 20. Innes, R.A., Sabourin, E.T. and Swift, H.E. (1979), Am. Chem. Soc.. Petrol. Chem. Prepr. 24,1065. 21. Innes, R.A. and Swift, H.A. (1981), ChemTech 11, 244. 22. Banks, R.L. (1984), in B.E. Leach (eds.), Applied industrial Catalysis 3, Academic Press, New York,

pp.215. 23. Logan, RS. and Banks, R.L. (1968), Hydrocarbon Process. 61, 135. 24. Logan, R.S. and Banks, R.L. (1968), Oil Gas 1.66,131. 25. Crain, D.L. and Reusser, RE. (1972), Am. Chem. Soc., Petrol. Chem. Prepr. 17, E80. 26. Burnett, RL. and Hughes, T.R. (1973),1. Catal. 31,55. 27. Chauvin, Y., Commereuc, D. and Cruypelinck, D. (1976), Makromol. Chem. 177,2637. 28. Graulich, W., Swodensk, W. and Theisen, D. (1972), Hydrocarbon Process., 71. 29. Breslow, D.S. (1990), ChemTech 20,540. 30. Thorn-Csanyi, E., private communication. 31. Streck, R. (1982) Some applications of the olefin metathesis reaction to polymer synthesis, I. Mol.

Catal. 15,3-19. 32. Marbach, A. and Hupp, R. (1989), Rubber World June, 30.

261

33. Mutch, A., Leconte, M., Lefebvre, F. and Basset, 1.M. (1998) Effect of alcohols and epoxides on the rate of ROMP of norbomene by a ruthenium trichloride catalyst, J. Mol. Cara!., A: General 133, 191-199.

34. Bell, A; (1992), J. Mol. Catal. 76,165. 35. Kloziewicz, D.W. (1983), U.S. pat. 4400340. 36. Basset, 1.M., Leconte, M., Ollivier, 1. and Quignard, F. (1989), U.S. pat. 4 861848. 37. Van Deursen, 1.H. and Sjardijn, W. (1989), Chern. Mag., 669. 38. Kohara, T., Masayoshi, O. and Natsuume, Y. (1991), U.S. pat. 5 063 096. 39. Murakami, T., Kohara, T. and Tadao, N. (1992), U.S. pat. 5106920. 40. Nishi, Y., Masayoshi, O. Tadao, N. and Kohara, T. (1992), U.S. pat. 5 143979. 41. Takahashi, N., Kohara, T. and Tadao, N. (1993), U.S. pat. 5187012 42. Kohara, T. and Tadao, N. (1994), U.S. pat. 5 276098. 43. Kohara, T. and Tadao, N. (1994), U.S. pat. 5 302656. 44. Hani, T., Nobukazu, T., Kohara, T. and Tadao, N. (1994), U.S. pat. 5 334424.