Addition polymers cyclooctene

Emrick and Coughlin et al. reported on the synthesis of cadmium selenide-polymer composites. A vinylbenzyl-derivatized phosphine oxide was ph-ysisorbed onto cadmium selenide particles. Subsequent reaction with RUCI2 (PCy3)2(CHPh) or RuCl2(NHC)(PCy3)(CHPh) (NHC= 1,3-dimesityhmidazol-2-ylidene) followed by addition of cyclooctene, 7-oxanorborn-5-ene-2,3-dicarboxylic anhydride, dicyclopentadiene or N-methyl-7-oxanorborn-5-... 

Novak et al., 1992) of cyclooctene to form polyoctenamer. Quite surprisingly, the double bond is maintained in the polymer, i.e., it is not a normal addition polymer. The generally accepted mechanism for these... 

The 5-substituted cyclooctenes (106-116, 118) generally give unbiased polymers, the substituent being too far away from the reaction site to influence the direction of addition of monomer. This is particularly clearly seen in the 13 C NMR spectrum of the polymer of 118, made using 19 as initiator, the olefinic region consisting of two well-defined symmetrical quartets (1 1 1 1) attributable to cis and trans olefinic carbons within HH, HT, TH, TT structures362. 

The meta photocycloaddition of cis-cyclooctene to benzene was one of the first examples of this reaction reported, and the addition of this cycloalkene to low molecular weight polystyrene and mono- and di-aromatic model-compounds has now been described. The results were analysed by mass spectroscopy, and it was reptorted that for polymers having up to six styrene units, more than one phenyl group in each chain had reacted. In the 2 1... 

The ring-opening polymerization of a simple cyclic olefin such as cyclooctene yields two structures of maximum order, which are distinguished by the configuration (cis or irans) of their main-chain olefins. In contrast, polymers made from bicyclic olefins such as norbornene are inherently more complicated and have four structures of maximum order (Scheme 24). In addition to cis- and trans-olefins, the polymers can also be isotactic or syndiotactic. The stereochemistry of these polymers becomes even more complicated when the monomer is asymmetric, since head—head, head—tail, and tail—tail regioisomers are possible. Nevertheless, single-site metathesis catalysts have been developed that can control polymer stereochemistry to an impressive degree by both chain-end and site-control mechanisms. ° ° ... 

In recent years, crosslinkable polymers have found a wide demand in the areas of interpenetrating polymer networks, non-linear optical materials, macro- and microlithography, and the formation of more thermally and chemically resistant materials. With this in mind, the controlled ROMP of 5-methacryloyl-l-cyclooctene (Scheme 8) was investigated to produce a linear polymer with cross-linkable methacrylate side chains. In addition, the copolymerisation of this monomer with cyclooctadiene (Scheme 9) allowed for the incorporation of a varying number of methacrylate side chains on the polymer backbone [23]. These copolymers were crosslinked through the methacrylate side chains with either thermal or photochemical initiation. Reaction of this multifunctionalised methacrylate polymer with methyl methacrylate under free radical polymerisation conditions led to the formation of AB crosslinked systems of poly(methyl methacrylate). A comparison of the... 

ROMP and PROMP are very useful methods to synthesize a number of novel materials with unique properties. Poly(cyclooctenes), poly(norbornenes) and poly(acetylenes) were discussed in more details and some of their properties like Tg, cristallinity, oxygen permeability, dielectric properties etc. listed. The polymerization of the cycloolefins was done either thermally or photochemically with the "old" Ru(II)-salts and the later developed Ru-phosphines as catalysts, whereas substituted acetylenes were photo-polymerized with W-, Mo- and Ta-catalysts. In addition, polymeranalogous transformations of the double bonds in ROMP polymers, (additions and cyclo-additions, epoxidation, (photo) crosslinking etc.) were discussed. We are convinced that these materials and systems will find useful applications in the near future. 

After Kaminsky, Brintzinger, and Ewen discovered homogeneous metallocene/ methylaluminoxane (MAO) catalysts for stereospecific a-olefin polymerizatiOTi (for reviews on olefin polymerization, see [13-21]), the first report [22, 23] rai addition cycloolefin polymerization without ROMP appeared. This stimulated a great interest in these polymers and in catalysts for cycloolefin polymerization (Fig. 1). Cycloolefins such as cyclopentene, cyclooctene, and norbomene can be polymerized via addition (Fig. 2). Polycycloolefins by metallocenes are difficult to process due to their high melting points and their low solubility in common organic solvents. However, metallocenes allow the synthesis of cyclic olefin copolymers (COC), especially of cyclopentene and norbomene with ethene or propene, which represent a new class of thermoplastic amorphous materials (Scheme 1) [24, 25]. 

We have arrived at a similar conclusion concerning an additional coordination of a double bond on the grounds of the molecular weight distribution of the oligomers in the initial stage of the reaction whidh corresponds to a Schulz-Flory distribution controlled by addition and transfer reactions. As well the formation of oligomers of cyclooctene and cyclododecene and the monomer-polymer equilibrium in the case of the metathetical polymerization of cyclopentene can be made plausible by this concept (Fig. 8). 

It should be noted that there are two ways of incorporating bicyclo-2,2,l-octene units into polymers. It is necessary to consider the distributions of the asymmetric centers present in polymers derived from this monomer in addition to considering the cis and trans structures present, to completely interpret the spectra of polymers derived from bicyclo-2,2,1-octane. Polymers derived from unsymmetrical cyclic olefins, in general, should not be e3q>ected to be stereoregular. However, cmr and pmr studies of polymers derived from 1-methyl cyclobutene and 1-methyl-trans-cyclooctene have predominantly head-tail structures [93,94]. Since they contain both cis- and trans- inits, they can be considered to be stereoregular copolymers. 

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