Triene monomers

Triallyl monomers [e.g. (21) or salts thereof] can potentially undergo two successive intramolecular cyclizationsX15 1 However, in practice these materials give insoluble products. 

The first cyclization gives a mixture of cis- and from -isomers and only the cis-isomer goes on to give bicyclic products. The relatively slow rate of the second cyclization step, and the formation of rrou.s-product which does not cyclize, provides an explanation for the observation that radical polymerizations of triallyl monomers often give a crosslinked product. 

It has been suggested that certain 1,5-dienes including o-divinylbenzene (23),156 vinyl acrylate (24, X 11) and vinyl methacrylate (24, X CH )120 may also undergo cyclopolymerization with a monomer addition occurring prior to cyclization and formation of a large ring. However, the structures of these cyclopolymers have not been rigorously established. 

Bicyclo[2,2,l]hcptadiene derivatives (25) are set up to undergo ring closure to form a three-membered ring and it is proposed that polymers formed from (25) contain predominantly nortrieyclene units.I57-1 8 

Various dimethacrylates have been polymerized in an effort to synthesize a poly(melhacrylale) with head-to-bead linkages.114 115 Various 1,6- e.g. dimcthacrylamidcs - see Tabic 4.4), 1,7- (e.g, dimcthacrylhydrazincs) and 1,8-dienes (e.g. dimethacryloylureas) are reported to give head-to-head addition (five-, 

Geometric considerations would seem to dictate that 1,4- and 1,5-dicncs should not undergo cyclopolymerization readily. However, in the case of 1,4-dienes, a 5 hexenyl system is formed after one propagation step. Cyclization via 

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The policyclic triene monomer undergoes metathesis polymerisation exclusively by the cyclobutene double bond under mild conditions (in toluene solution at 20 °C) to give a soluble precursor polymer. This polyacetylene precursor can be purified and characterised prior to its conversion at elevated temperature, via thermally initiated symmetry-allowed elimination (retro Diels-Alder reaction), to polyacetylene (a heat treatment of the product also results in isomerisation of the initial cis form to a more stable turns form) [150],... 

Myrcene is an interesting diene (actually triene) monomer since it has an isolated double bond in its alkyl side chain. Thus, this monomer provides a unique opportunity to study the effects of internal ir-bond interactions in living anionic polymerizations and also to examine the effects of this functionality on the physical properties of poly(myrcene) and various block copolymers as reported herein. 

Nylon 12 first beeame available on a semieommercial scale in 1963. The monomer, dodecanelactam, is prepared from butadiene by a multistaged reaction. In one proeess butadiene is treated with a Ziegler-type eatalyst system to yield the cyclic trimer, cyclododeca-1, 5, 9-triene. This may then be hydrogenated to give cyelododeeane, which is then subjeeted to direct air oxidation to give a mixture of cyclododecanol and cyclododecanone. Treatment of the mixture with... 

The monomer (laurolactam) could he produced from 1,5,9-cyclododeca-triene, a trimer of hutadiene (Chapter 9). The trimer is epoxidized with peracetic acid or acetaldehyde peracetate and then hydrogenated. The saturated epoxide is rearranged to the ketone with Mgl2 at 100°C. is then changed to the oxime and rearranged to laurolactam. 

Two ended living polynorbornene 23 was prepared with difunctional initiator 22a, b, and anti-7,8-benzotricyclo[4.2.2.02,5]deca-3,7,9-triene 26 was added as a second monomer to produce a triblock copolymer with a poly(norbornene) middle segment, Eq. (29) [42b]. Naphthalene cleavage occured upon heating to temperatures above 120 °C. The product of thermolysis is polyacetylene/polynorbor-nene/-polyacetylene triblock copolymer 28. 

As an alternative, copolymerization of alkynes bearing bulky substituents with TCDTF6 (7,8-bis(trifluoromethyl)tricyclo [4.2.2.0 ]deca-3,7,9-triene) was carried out. In the course of this copolymerization, usually referred to as the Durham Route [86-89], the Feast-monomer was introduced into the polymer main chain and subsequently converted into three unsubstituted, conjugated double bonds via a thermally-induced retro-Diels Alder reaction (Scheme 3) [53]. 

Systematic studies were carried out on copolymers of isobutene with 1,3,5-hexatriene (HTI) and 2,4,6-octatriene (OTI). The structure of the triene units present in the copolymer chains was determined by riKans of C-NMR by making reference to the cationic triene homopolymers and to the same copolymers previously hydrogenated. In the case of HTI there are only traces of repeat units descending from the 1,2- and 1,4-opening of the trienic system, the 1,6-enchainment being prevalent some cyclic structures are also present The cationic homopolymer of 2,4,6-octatriene results from the preval t (ca. S)%) 2,7-opening of the monomer, while the remainder unit results from 2,5-addition. A similar situation also seems to be present in OTI ... 

Except for the elimination of HCI, pyrolysis products of polychloroprene correspond rather well with those of isoprene. Besides the monomer and 3,7-dichloroocta-1,4,6-triene (which can be considered as a dimer of chloroprene), another compound found in appreciable levels in polychloroprene pyrolysate is 1-chloro-5-(1-chloroethenyl)-cyclohexene. This compound corresponds to diprene or 1-methyl-5-(1-methyivinyl)-cyclohex-1 -ene in the pyrolysate of polyisoprene. 

High solubility has also been achieved by using l-thia-4,5-diaza-cyclohepta-2,4,6-triene as an heterocyclic monomer unit [60]. The polyamides 43 not only have high solubility in DMSO, HMPT, and NMP, and good solubility in DMF, and DMAc, but also have some solubility in formic acid. They decompose between 465-505 °C. 

It can be seen from Fig. 4 that many diene monomers were polymerized using various hosts. It might be possible to polymerize multiconjugated monomers, such as trienes and tetraenes, in one-dimensional spaces. Diacetylene spontaneously polymerized in channels of three hosts perhydrotriphenylene, deoxycholic acid, and apocholic acid. On the other hand, there are not so many studies of the polymerization of vinyl monomers, because highly stereoregular polymers are not obtained. 

There are many possible schemes for addition reactions of diene monomers from electronical and steric viewpoints. Because the monomer molecules arrange along the direction of the channels, a,co-addition may selectively take place in one-dimensional inclusion polymerization. Therefore, conjugated polyenes, such as dienes and trienes, may selectively polymerize by 1,4- and 1,6-addi-tion, respectively. 1,3-Butadiene polymerized via 1,4-addition exclusively in the chaimels of urea and perhydrotriphenylene. while the same monomer polymerized via both 1,2- and 1,4-additions in the channels of deoxycholic acid and apocholic acid. Moreover, we have to evaluate head-to-tail or head-to-head (tail-to-tail) additions in the case of dissymmetric conjugated diene monomers such as isoprene and 1.3-pentadiene. 

The first hving polymerization of cyclic olefins with a high ring strain [28], such as norbomenes, norbornadienes (bicyclohepta-2,5-dienes, NBDs) or the Feast-monomer 7,8-bis(trifluoromethyl)tricyclo[4.2.2.0 ]deca-3,7,9-triene (TCDTFj) by W(N-2,6 i Pr2 C6H3)(CH- Bu)(OCMe(CF3)2) [34] was re-... 

Acyclic triene metathesis (ATMET) polymerisation is a particular ADMET application useful in vegetable oils. ADMET can also be used for the polymerisation of triglycerides, offering the possibility to obtain branched polymers directly from plant oils without prior chemical modification, thereby helping to further minimise the environmental impact of snch materials. This type of polymerisation was termed ATMET with reference to monomer functionality [51]. 

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