Alkaline poly

Fauvarquet JF, Guinot S, Bouzir N, Salmon E, Penneau JF (1995) Alkaline poly(ethylene oxide) solid polymer electrolytes. Application to nickel secondary batteries. Electrochim Acta 40 2449... 

DA1 Daoust, H. and Hade, A., Effect of cation size on heats of dilution of aqueous solutions of alkaline poly (sty renesulfonates). Macromolecules, 9, 608, 1976. 

Fauvarque, J.F., Guinot, S., Bouzir, N., Salmon, E., Penneau, J.F. (1995) Alkaline poly (ethylene oxide) solid polymer electrolytes application to nickel secondary batteries. Electrochimica Acta, 40, 2449-2453. 

Yang, C.C., Lin, S.J., Wu, G.M. (2005) Study of ionic transport properties of alkaline poly(vinyl) alcohol-based polymer electrolytes. Materials Chemistry and Physics, 92, 251-255. 

As a furtlier example for tire meaning of ex situ investigations of emersed electrodes witli surface analytical teclmiques, results obtained for tire double layer on poly crystalline silver in alkaline solutions are presented in figure C2.10.3. This system is of scientific interest, since tliin silver oxide overlayers (tliickness up to about 5 nm) are fonned for sufficiently anodic potentials, which implies tliat tire adsorjDtion of anions, cations and water can be studied on tire clean metal as well as on an oxide covered surface [55, 56]. For tire latter situation, a changed... 

Poly(acrylic acid) and Poly(methacrylic acid). Poly(acryHc acid) (8) (PAA) may be prepared by polymerization of the monomer with conventional free-radical initiators using the monomer either undiluted (36) (with cross-linker for superadsorber appHcations) or in aqueous solution. Photochemical polymerization (sensitized by benzoin) of methyl acrylate in ethanol solution at —78° C provides a syndiotactic form (37) that can be hydrolyzed to syndiotactic PAA. From academic studies, alkaline hydrolysis of the methyl ester requires a lower time than acid hydrolysis of the polymeric ester, and can lead to oxidative degradation of the polymer (38). Po1y(meth acrylic acid) (PMAA) (9) is prepared only by the direct polymerization of the acid monomer it is not readily obtained by the hydrolysis of methyl methacrylate. 

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. 

Under conditions of extreme acidity or alkalinity, acryhc ester polymers can be made to hydroly2e to poly(acryhc acid) or an acid salt and the corresponding alcohol. However, acryhc polymers and copolymers have a greater resistance to both acidic and alkaline hydrolysis than competitive poly(vinyl acetate) and vinyl acetate copolymers. Even poly(methyl acrylate), the most readily hydroly2ed polymer of the series, is more resistant to alkah than poly(vinyl acetate) (57). Butyl acrylate copolymers are more hydrolytically stable than ethyl acrylate copolymers (58). 

Many other polymerization processes have been patented, but only some of them appear to be developed or under development ia 1996. One large-scale process uses an acid montmorrillonite clay and acetic anhydride (209) another process uses strong perfiuorosulfonic acid reski catalysts (170,210). The polymerization product ia these processes is a poly(tetramethylene ether) with acetate end groups, which have to be removed by alkaline hydrolysis (211) or hydrogenolysis (212). If necessary, the product is then neutralized, eg, with phosphoric acid (213), and the salts removed by filtration. Instead of montmorrillonite clay, other acidic catalysts can be used, such as EuUer s earth or zeoHtes (214—216). 

Reaction of olefin oxides (epoxides) to produce poly(oxyalkylene) ether derivatives is the etherification of polyols of greatest commercial importance. Epoxides used include ethylene oxide, propylene oxide, and epichl orohydrin. The products of oxyalkylation have the same number of hydroxyl groups per mole as the starting polyol. Examples include the poly(oxypropylene) ethers of sorbitol (130) and lactitol (131), usually formed in the presence of an alkaline catalyst such as potassium hydroxide. Reaction of epichl orohydrin and isosorbide leads to the bisglycidyl ether (132). A polysubstituted carboxyethyl ether of mannitol has been obtained by the interaction of mannitol with acrylonitrile followed by hydrolysis of the intermediate cyanoethyl ether (133). 

Cationic poly(vinyl alcohol) has been prepared by the reaction of A/-(3-chloro-2-hydroxypropyl)-Ai,Ai,A/-trimethylammonium chloride, PVA, and sodium hydroxide (143). Reactions between alkyUdene epoxide and PVA in particulate, free-flowing form in an alkaline environment have been reported (144). 

The catalysts most often described in the literature (209—211,252) are sodium or potassium hydroxide, methoxide, or ethoxide. The reported ratio of alkali metal hydroxides or metal alcoholates to that of poly(vinyl acetate) needed for conversion ranges from 0.2 to 4.0 wt % (211). Acid catalysts ate normally strong mineral acids such as sulfuric or hydrochloric acid (252—254). Acid-cataly2ed hydrolysis is much slower than that of the alkaline-cataly2ed hydrolysis, a fact that has limited the commercial use of these catalysts. 

Alkaline (and also acidic) ester hydrolysis of /3-poly(L-malate) is accompanied by side reactions leading to the formation of fumarate, maleate and/or racemiza-tion, especially at elevated temperatures. The above assays thus underestimate the polymer contents due to the formation of small amounts of 2-4% fumarate (unpublished results). This fraction of fumarate increases for the hydrolysis of more concentrated polymer solutions. 

Poly(L-malate) decomposes spontaneously to L-ma-late by ester hydrolysis [2,4,5]. Hydrolytic degradation of the polymer sodium salt at pH 7.0 and 37°C results in a random cleavage of the polymer, the molecular mass decreasing by 50% after a period of 10 h [2]. The rate of hydrolysis is accelerated in acidic and alkaline solutions. This was first noted by changes in the activity of the polymer to inhibit DNA polymerase a of P. polycephalum [4]. The explanation of this phenomenon was that the degradation was slowest between pH 5-9 (Fig. 2) as would be expected if it were acid/base-catalyzed. In choosing a buffer, one should be aware of specific buffer catalysis. We found that the polymer was more stable in phosphate buffer than in Tris/HCl-buffer. 

Whereas the cleavage of /S-poly(L-malate) at neutral pH is at random [2], alkaline hydrolysis reveals characteristic patterns of the cleavage products, which is due to nonrandom chain scission (Fig. 3). The phenomenon is explained by an autocatalytic ester hydrolysis. Assuming that one (or both) of the polymer ends bends... 

Figure 3 Reversed-phase chromatography of products after alkaline hydrolysis of /3-poly(L-malate), Discrete polymer products are formed, which differ in length by several units of L-malate. The absorbance at 220-nm wavelength was measured, (a) /3-Poly(L-malate) before hydrolysis, (b) After 10-min incubation in 20 mM NaOH at 37°C. (c) After 15 h in 20 mM NaOH at 37°C. (d) After I h in 500 mM NaOH at 100°C. High pressure chromatography (HPLC) on Waters reversed-phase Ci8- i-Bondapak. The methanol gradient (in water-trifluoro acetic acid, pH 3.0) was programmed as follows 0-40 min 0.3-23%, 40-47 min 23-40%, 47-49 min 40%, 49-54 min 40-0%. (d) Inset size exclusion chromatography after 3-min alkaline hydrolysis at pH 10.2. BioSil SEC 250 column of 300 mm x 7.8 mm size, 0.2 M potassium phosphate buffer pH 7.0.

Several of the current synthetic semi-fluid lubricants for worm gears are based on a poly-alkaline glycol - which possesses slipperiness . Oxidation and rust-inhibitors are... 

Arcus and co-workers94 studied alkaline hydrolyses of neutral and anionic aliphatic esters in the presence of poly (vinylbenzyltriethylammonium hydroxide), 42 (PVBzTEA), as a catalyst. Baumgartner and associate95 also found enhanced alkaline hydrolyses of 43 (aspirin, anionic substrate), in the presence of 42 (PVBzTEA), in alkaline pH regions. 

Cordes et al995 carried out alkaline hydrolyses of p-nitrophenylhexanoate 55 (PNPH) in the presence of poly-4-vinylpyridine partially quaternized with dodecyl-bromide and ethylbromide (QPVP). They also found that the polyelectrolytes are increasingly effective as catalysts with an increasing ratio of dodecyl to ethyl groups, and the hydrophobic interactions are important in determining the catalytic efficiency. They observed the inhibitory effects of several gegen-anions fluoride ions are the weakest inhibitor, and nitrate is the strongest (F- < Cl < S04 [Pg.159]

We also found the saturation kinetics for alkaline hydrolyses of 44 (PNPA), 3-nitro-4-acetoxybenzoic acid 56 (NABA), and 3-nitro-4-acetoxybenzenearsonie acid 57 (NABAA) in the presence of QPVP1025. If ester-polymer complex formation occurs prior to the attack of OH-, Eq. (5) holds, according to Bunton etal. 103 where K is the equilibrium association constant of polyelectrolyte (PE) and ester (S), and kt the first-order rate coefficients1035, PE, S, and P indicate the poly-... 

Recently, the quaternized poly-4-vinylpyridine, 50-54 (QPVP) was found to be an electron acceptor in the charge-transfer interactions 104 Ishiwatari et al.105) studied alkaline hydrolyses of p-nitrophenyl-3-indoleacetate 58 (p-NPIA) and N-(indole-3-acryloyl) imidazole 59 (IAI) (electron donor) in the presence of QPVP. The fcobs vs. polyelectrolyte concentration plots are shown in Fig. 12. As is seen in... 

We recently synthesized cationic polymers containing imidazole (e g. 68 (SZ811) and 69 (SZ11—3—3)] by reacting poly [N-(2,4-dinitrophenyl)-4-vinyl-pyridinium chloride] with histamine or histamine mixed with other amino derivatives ll8 The hydrolyses of neutral and anionic esters with the models followed saturation kinetics in alkaline media. 

Phase-separated polymers, 215 Phase separation, 217-222 Phase transfer catalysts, 288, 563-564 Phase-transfer-catalyzed alkaline hydrolysis of nylon-4,6, 570 of nylon-6,6, 569-570 PHB. See Poly(3-hydroxybutanoic acid) (PHB)... 

Journal of Applied Polymer Science 82, No. 1, 3rd October 2001, p.99-107 ALKALINE DEPOLYMERISATION OF POLY(TRIMETHYLENE TEREPHTHALATE)... 

Macromolecular Materials and Engineering 286, No. 10, 25th Oct.2001, p.640-7 POLY(ETHYLENE TEREPHTHALATE) RECYCLING AND RECOVERY OF PURE TEREPHTHALIC ACID. KINETICS OF A PHASE TRANSFER CATALYZED ALKALINE HYDROLYSIS... 

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