Allyl ethers, polymerization

Thiol-Ene Photopolymerization The thiol-ene polymerization of suitable systems (10.84) in film is insensitive to oxygen. The reaction refers to the addition of a thiol to a double bond (e.g., vinyl, allyl, acrylate, and methacrylate) [310] and has led in these past years to a new revival of interest [311,312]. Thiol-vinyl ether or -allyl ether polymerization shows some following interesting features very fast process, low or even no oxygen inhibition effect and formation of highly cross-linked networks with good adhesion, and physical and mechanical properties. 

Nickel-bpy and nickel-pyridine catalytic systems have been applied to numerous electroreductive reactions,202 such as synthesis of ketones by heterocoupling of acyl and benzyl halides,210,213 addition of aryl bromides to activated alkenes,212,214 synthesis of conjugated dienes, unsaturated esters, ketones, and nitriles by homo- and cross-coupling involving alkenyl halides,215 reductive polymerization of aromatic and heteroaromatic dibromides,216-221 or cleavage of the C-0 bond in allyl ethers.222... 

Ru(H20)6], which is a precursor of ROM polymerization of cyclic dienes has also been found to possess good alkene isomerization activity [1], Among others it catalyzed the isomerization of allylphenyl ether to a vinylphenyl ether (Scheme 9.1) at room temperature. Allyl ethers are stable to acids and bases, while vinyl ethers are easily cleaved in acidic solutions. Therefore this isomerization gives a mild method for removal of protecting allyl groups under exceedingly mild conditions. 

The methyl and ethyl ethers of the dianhydrides have properties which may make them useful as plasticizers. 2,5-Diallyl-dianhydro-sorbitol (XVII) and 2,5-diallyl-dianhydro-mannitol (XVIII) and the corresponding methallyl derivatives polymerize to resinous materials on being heated in oxygen.The allyl derivatives polymerize about five times as fast as the methallyl derivatives, to give products somewhat similar to that obtained by Nichols and Yanovsky by the polymerization of methyl tetraallyl-a-n-glucoside. 

Propenyl Ethers and Unsaturated Cyclic Ethers Propenyl ethers (CH3—CH=CH—OR R = ethyl, isobutyl, etc. cis- and trans-isomers) and 3,4-dihydrofuran are linear and cyclic a,/3-unsaturated ethers, that can be regarded as / -substituted vinyl ether derivatives. For these monomers a few controlled/living cationic polymerizations have been reported. The HI/I2 system is generally effective for both linear and cyclic monomers [181,182,183], whereas a recent study by Nuyken indicates that the IBVE-HI adduct coupled with nBu4NC104 is suited for 3,4-dihydrofuran (see Section V.A.4) [184]. A variety of mono- and bifunctional propenyl ethers can readily be prepared by the ruthenium complex-catalyzed isomerization of corresponding allyl ethers [185]. 

Taking advantage of the fast transacetalization (scrambling) accompanying the cationic polymerization of 1,3-dioxolane, the telechelic polymers containing two allyl ether groups were obtained in the polymerization carried out in the presence of bis(allyloxy)methane (the carboxonium active species showed in the scheme for simplicity) ... 

The first example of fully aqueous metal catalysis of olefin isomerization was reported by Grubbs et al. in 1994 [2]. These authors adopted [Ru(H20)6](tos)2 (tos = p-toluenesulfonate) [8] as a catalyst, which is highly active for the ring-opening polymerization of strained cyclic olefin. Both allylic alcohol and allylic ethers undergo isomerization in the presence of [Ru(H20)6](tos)2. 

Figure 11 General scheme for ring-opening metathesis polymerization (ROMP). Monomer 1 and catalyst 2 continue to react until the monomer has been consumed yielding polymer 4, which can be end-capped with functionalized allyl ether 5.

The polymerization is said to be fast with a low energy input, is not inhibited by air, uses no solvents, is nonpolluting, and uses inexpensive materials. The photopolymerization of various epoxidized oils and terpenes also does this. The propenyl ethers were made by isomerization of the corresponding allyl ethers with a ruthenium catalyst. The allyl ethers were made from the hydroxy compounds with allyl bromide and base, a process that produces waste salts. It is possible that the monomers could be made by reaction of the hydroxy compounds with propylene oxide followed by dehydration so that no waste salts would be formed. Isosorbide is made by the acid-catalyzed dehydration of sorbitol, in turn, obtained by the reduction of glucose. 

Other monomers (for example acrylamide, styrene, vinylpyrrolidone, vinylcar-bazole, vinyl ether, allyl ether, etc.) can be likely studied by carefully selecting other initiating radicals. Cross-polymerization might also be investigated, for example, the addition of TEA-M to vinyl ether since TEA does not react with vinyl ether. The results obtained with this procedure can also be extended to the behavior of different acrylate structures in photopolymerization experiments carried out in bulk. 

Rash pt 70 F open cup) 5 F closed cup) autoig-nition temp 7l3 F. 72.3% of the alcohol with 27.7% water forms a constant boiling mixture, bp at 87.5. Miscible with water, alcohol chloroform, ether, petr ether. Keep lightly closed. Upon storage for several years allyl alcohol polymerizes and a thick syrup is formed (insol in water, so] in chloroform) which on treatment with ether yields a brittle resin -oid mass Blicke. J. Am. Chem. Soc. 45, 1563 (1923) LDs0 orally in rats 64 mg/kg, Smyth, Carpenter J. Ind. Hyg. Tivcicot. 30, 63 (1948). 

Glyceryl-1-allyl ether PU solid elastomer mfg. 1,5-Naphthalene diisocyanate PU, adhesives Polymeric MDI PU, appliances Polymeric MDI PU, automotive... 

In recent years, there has been a considerable interest in the use of polymerizable surfactants for latices. Such surfactants contain a polymerizable group which may be an acrylate, a methacrylate, an allyl ether or a maleate double bond. Both anionic and nonionic reactive surfactants are commercially available. The polymerizable surfactant is usually added from the beginning, in essence serving as a comonomer in the emulsion polymerization. The reactive surfactant may... 

Ptobably the first graft copolymer was based on cellulose, Ushakov (33) who attached vinyl or allyl ethers to cellulose and used these sites to initiate the copolymerization with maleic acid esters. Another early paper was by Jahn (34). Graft polymerization of cellulose has been an active field, at least until recently, and well over a thousand papers and patents have been issued. 

Only a few articles deal with the polymerization of phosphorus-containing allyl ether monomers. Most of them discuss radical polymerization however, the strong stability of allyl ether radicals is probably a disadvantage, leading to longer polymerization times compared with those of the more reactive vinyl ethers. 

Shim et al., reported preparation of several novel mono- and di-propenyl ethers by condensation of perfluoroalkyl alcohol with allyl bromide followed by the ruthenium-catalyzed isomerization of the corresponding allyl ethers. These fluorinated propenyl ethers undergo rapid photoinitiated cationic polymerization with the aid of triaryl-sulfonium salt bearing a long alkoxy... 

Carlsson, 1 Karden, A Lundmark, S., Manea, A., Rehnberg, N. and Svensson, L., Allyl ethers in the thiol-ene reaction, in Photoinitiated Polymerization, Belfield K.D. and Crivello J.V. (Eds.), American Chemical Society, Washington DC, ACS Series 2003, 847, 65-75. 

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