Sodium-4-vinylbenzoate

Sodium 4-styrenesulfonate-5foc -sodium 4-vinylbenzoate block copolymer, 20 487 Sodium 4-vinylbenzoate, 20 469 Sodium acetate in PVA, 25 613... 

We have recently evaluated the ATRP of a wide range of hydrophilic monomers such as 2-sulfatoethyl methacrylate (SEM), sodium 4-vinylbenzoate (NaVBA), sodium methacrylate (NaMAA), 2-(dimethylamino)ethyl methacrylate (DMA), 2-(iV-morpholino)ethyl methacrylate (MEMA), 2-(diethylamino)ethyl methacrylate (DEA), oligo(ethylene glycol) methacrylate (OEGMA), 2-hydroxyethyl methacrylate (HEMA), glycerol monomethacrylate (GMA), 2-methacryl-oyloxyethyl phosphorylcholine (MPC), and a carboxybetaine-based methacrylate [CBMA]. Their chemical structures and literature references (which contain appropriate experimental details) are summarised in Table 1. 

Water is the solvent of choice for ionic monomers such as sodium methacrylate, where a direct radical polymerization (i.e., with the nonprotected form of the monomer) is carried out with the copper-based systems in aqueous media (pH 8—9) at 90 °C to afford controlled molecular weights and narrow MWDs.200 Another ionic monomer, sodium 4-vinylbenzoate, is polymerized very fast in aqueous media (pH 11) at 20 °C.247 An ammonium salt monomer, [2-(methacryl-oxy)ethyl]trimethylammonium chloride (FM-6 Figure 12), was polymerized in water with CuBr/L-1 in conjunction with a surface-confined initiator, while... 

More recently controlled free radical polymerization methodologies have been employed for the preparation of novel smart AB diblock copolsrmers. Nitroxide-mediated polymerization was utilized for the synthesis of sodiiun 4-styrenesulfonate-block-sodium 4-vinylbenzoate block copolymer (133). These strong acid/weak acid species exhibit reversible pH-induced self-assembly, with the sodium 4-styrenesulfonate residues remaining ionized and thns permanently hydrophilic over the useful pH range whereas the sodium 4-vinylbenzoate block can be reversible protonated (the carboxylate residue has a pa s 4.0). The same block polymers can also be prepared via RAFT, albeit with somewhat more control. Other workers reported the preparation of such AB diblock copolymers as well as some analogous amine-based styrenic diblock copolymers, (48) shown in Figure 54. 

A big advantage of any radical process, ATRP included, is its tolerance to many functional groups such as amido, amino, ester, ether, hydroxy, siloxy and others. All of them have been incorporated as substituents into (meth)acrylate monomers and successfully polymerized. One current exception is a Tree carboxylic acid group which potentially complexes with the catalyst and disables ATRP, and therefore, presently, it has to be protected. Recent work has shown that monomers bearing ionic substituents such as sodium 4-vinylbenzoate, sodium 4-vinylbenzylsulfonate and 2-trimethylammonioethyl methacrylate methanesulfonate and triflate, and dimethylaminoethyl methacryate can be polymerized directly [148]. 

To carry out SFEIP in homogeneous aqueous solutions, the radical mediator, as also the monomer and the polymers, should be soluble in the medium. A number of water-soluble monomers have been polymerized by the living radical process (Qiu et al., 2001). They include uncharged monomers, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, oligo(ethylene glycol) methacrylate, 2-(dimethylamino)ethylmethacrylate, acrylic acid, etc., and charged/ionic monomers, such as sodium methacrylate, sodium vinylbenzoate (NaVBA) and sodium styrene sulfonate (NaSS). 

Hydrogenation reduces the nitro group to amino which is then diazotized using sodium nitrite and tetrafluoroboric acid. The diazotized crown was not isolated but the aq. solution was treated directly with sodium acetate and bis(dibenzylideneacetone)-pal-ladium(O) in acetonitrile solution. Ethylene was then introduced to the autoclave and the solution was allowed to stir for 2 days. 4 -Vinylbenzo-15-crown-5 was isolated (30% from 4 -nitrobenzo-15-crown-5) as a colorless solid (mp 43.5—44.2°) °. The synthesis is illustrated in Eq. (3.16). 

C-allylation of PhO" Na with H2C=CHCH2C1 in a variety of solvents in the presence of different crown ethers is most effective in each case when using poly(vinylbenzo-15-crown-5)polyether. Only in the presence of the crown ethers 15-crown-5 and 18-crown-6 are the anions in potassium phthalimide and sodium saccharinate, respectively, sufficiently activated to bring about nucleophilic aromatic substitution of the 4-fluorine in pentafluoropyridine. The formation of 2,4-dinitrophenol, in addition to the expected ether, from 2,4-dinitrochlorobenzene and potassium 2-propoxide in 2-propanol-benzene (1 1), in the presence of dicyclohexyl-18-crown-6 polyether, has been accounted for on the basis of a nucleophile-radical reaction (5rn1)/ ... 

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