Quaternized polymers

A modified poly(ethylenimine) also acts as an efficient catalyst for decarboxylation (Suh et al., 1976 Spetnagel and Klotz, 1976). In particular, the partially quaternized polymer [SS] catalyzed the decarboxylation of oxalacetic acid in a bifunctional manner (Spetnagel and Klotz, 1976), as shown in (18). The decarboxylation is thought to occur via pre-equilibrium... 

Comparing catalytic effects of different modified polyethylenimines on the decarboxylation of nitrobenzisoxazole carboxylate, we can discern several interesting features. Comparison of the 25% laurylated polymer in the quaternized and nonquaternized forms, A and D, respectively, in Table X, shows that the former is about three times more effective as a catalyst than the latter. For the quaternized polymer the first-order catalytic constant k2 and the second-order rate constant nk2IKM are greater and the binding of substrate (measured by XM ) is stronger. 

The ethyl-quaternized polymer is more effective as a catalyst than the comparable methyl-quaternized polymer (A and B, respectively, in Table X). This is due in large part to the threefold increase in k2, which can be interpreted as a reflection of the contribution of the more apolar environment provided by ethyl as contrasted to methyl groups. 

Quaternized polymers have been found to improve wet combing and reduce static charge. In general, they can be formulated with anionic surfactants greater deposition occurs with a mixture of amphoteric and nonionic surfactants. Two of the most important examples are Polyquaternium-10, a quaternized hydroxyethylcel-lulose polymer, and Polyquaternium-7, a copolymer of diallyldimethylammonium chloride and acrylamide. These are the two most frequently used polymeric conditioning agents in commercial shampoos [46,47],... 

Cationic polymers such as polymer JR (polyquaternium-10), a quater-nized cellulosic ingredient [6] cationic guar, a quaternized polymer of galactose Merquat polymers (polyquaternium-6 and -7) copolymers of dimethyl diallyl ammonium chloride and acrylamide [7] and Gafquat polymers (polyquaternium-11) (copolymer of polyvinyl pyrrolidone and dimethy-laminoethyl methacrylate) [8] have all been used and are currently used in conditioning shampoos, setting lotions, or mousses. 

PAES has been functionalized with quaternary guanidinium groups for use in polymeric hydroxide exchange membranes. The quaternized polymers could be synthesized by the chloromethylation of PAES, followed by the reaction with pentamethyl-guanidine, c.f.. Figure 7.15 [113]. 

The quaternized polymers exhibit an outstanding solubility in polar aprotic solvents. Therefore, flexible and tough membranes varying ionic content could be prepared by solution casting using dimethyl sulfoxide as solvent. The membranes have a high ionic conductivity and excellent chemical stability [113]. 

If the flexibility of the polymer chain is reduced, the tendency to fold in to domains must decrease. Each charge must be localized within the polymer backbone, which is a low dielectric region. Solvation of individual counterions will become the primary mode of product stabilization. If the counterions are tightly bound to individual groups, the solvent molecules must be highly ordered to effect solvation. Further, the extent of solvation will have a pronounced impact upon the stability of the transition state, and the reaction rate will be very sensitive to solvent variations. We have noted that DMSO is very difficult to remove quantitatively from quaternized polymers and that the polyquats are extremely hydroscopic. These observations indicate that solvent molecules are very strongly bound to the ionic sites. 

Due to the electrostatic repulsion between the pyridinium ions, the chains gradually unfold with the quaternization process, increasing in turn both its hydrodynamic volume and the viscosity of its solution. However, beyond a certain degree of quaternization, the solvating power of the medium toward the quaternized polymer decreases and the chains tend to shrink thus, the viscosity of the corresponding solution initially increases and then decreases with the extent of the modification reaction. 

Polyamines can also be made by reaction of ethylene dichloride with amines (18). Products of this type are sometimes formed as by-products in the manufacture of amines. A third type of polyamine is polyethyleneimine [9002-98-6] which can be made by several routes the most frequently used method is the polymeriza tion of azitidine [151 -56 ] (18,26). The process can be adjusted to vary the amount of branching (see Imines, cyclic). Polyamines are considerably lower in molecular weight compared to acrylamide polymers, and therefore their solution viscosities are much lower. They are sold commercially as viscous solutions containing 1—20% polymer, and also any by-product salts from the polymerization reaction. The charge on polyamines depends on the pH of the medium. They can be quaternized to make their charge independent of pH (18). 

Commercial grades of PVP, K-15, K-30, K-90, and K-120 and the quaternized copolymer of vinylpyrrolidone and dimthylaminoethylmethacrylate (poly-VP/ DMAEMA) made by International Specialty Products (ISP) were used in this study. PEO standard calibration kits were purchased from Polymer Laboratories Ltd. (PL), American Polymer Standards Corporation (APSC), Polymer Standards Service (PSS), and Tosoh Corporation (TSK). In addition, two narrow NIST standards, 1923 and 1924, were used to evaluate commercial PEO standards. Deionized, filtered water, and high-performance liquid chromatography grade methanol purchased from Aldrich or Fischer Scientific were used in this study. Lithium nitrate (LiN03) from Aldrich was the salt added to the mobile phases to control for polyelectrolyte effects. 

The quaternized copolymer of vinylpyrrolidone and dimethylaminoethylmetha-crylate (poly-VP/DMAEMA) has been analyzed successfully with Ultrahydrogel columns and a mobile phase of a 0.1 M Tris pH 7 buffer with 0.3 or 0.5 M lithium nitrate (14). In this study, poor recovery of a poly-VP/DMAEMA sample was noticed when 0.2 M lithium nitrate was used for KB-80M, SB806-MHQ, and TSK GM-PWxl columns. Good recovery was achieved with 0.4 M lithium nitrate, and M of the poly-VP/DMAEMA were found to be 290,000, 300,000, and 320,000 for the respective columns. This demonstrates the equivalence of these columns for SEC of cationic polymers. 

Further investigation of pyrrole polymer would be of considerable interest. Rather similar to the foregoing hypothetical reaction is the attempted quaternization of (21), which leads directly to (22), no quaternary salt surviving at all. ... 

The effectiveness of ylides in the field of polymer science was first described in 1966 by George et al. [11] who felt that 3- and 4-(bromo acetyl) pyridines, which contain both the a-haloketone and the pyridine nucleus in a single molecule, could be quaternized to polymeric quaternary salts and finally to polymeric ylides Schemes 9 and 10 by treating these polymeric salts with a base. 

The structures of these ylide polymers were determined and confirmed by IR and NMR spectra. These were the first stable sulfonium ylide polymers reported in the literature. They are very important for such industrial uses as ion-exchange resins, polymer supports, peptide synthesis, polymeric reagent, and polyelectrolytes. Also in 1977, Hass and Moreau [60] found that when poly(4-vinylpyridine) was quaternized with bromomalonamide, two polymeric quaternary salts resulted. These polyelectrolyte products were subjected to thermal decyana-tion at 7200°C to give isocyanic acid or its isomer, cyanic acid. The addition of base to the solution of polyelectro-lyte in water gave a yellow polymeric ylide. 

The pioneering work on amphiphilic polyelectrolytes goes back to 1951, when Strauss et al. [25] first synthesized amphiphilic polycations by quaternization of poly(2-vinylpyridine) with n-dodecyl bromide. They revealed that the long alkyl side chains attached to partially quaternized poly(vinylpyridine)s tended to aggregate in aqueous solution so that the polymers assumed a compact conformation when the mole fraction of the hydrophobic side chains exceeded a certain critical value. Thus, Strauss et al. became the first to show experimentally the intramolecular micellation of amphiphilic polymers and the existence of a critical content of hydrophobic residues which may be compared to the critical micelle concentration of ordinary surfactants. They called such amphiphilic polyelectrolytes polysoaps [25],... 

Various substituted styrenes have been also polymerized by NMP. These include 1 03-1 07, p-chloromethylstyrene (108), p-halostyrenes, and p-aceloxystyrene. Vinyl pyridines (e.g. 109) are amenable to NMP21 and may be quaternized post-polymerization to provide water-soluble polymers. 

Hamman et al. [281,282] tested five trimethyl chitosans with different degrees of quaternization as nasal delivery systems the degree of quaternization had a major role in the absorption enhancement of this polymer across the nasal epithelia in a neutral environment. 

Second, bromination of methyl groups attached to arylphenoxy-phosphazene polymers converted them to CH2Br units (22). These were then quaternized with triethylamine, and the quaternary sites were used for anion exchange with sodium heparin (Fig. 2). The... 

Even in solution the relative rigidity of the polymer support can play a significant role in the reactivity of attached functional groups. Contrasting studies conducted with chloromethylated derivatives of poly(arylene ether sulfone) (Tg 175°C), phenoxy resin (Tg= 65°C) and polystyrene (Tg= 105°C) allow evaluation of chain rigidity effects. We have shown that the rates of quaternization of chloromethylated poly(arylene ether sulfones) and phenoxy resin deviate from the anticipated second order process at... 

Deliberate production of (vinyl)polystyrene from (toluenesul-foxyethyl)polystyrene or (haloethyl)polystyrenes was best accomplished by quaternization with N,N-dimethylaminoethanol, followed by treatment with base beta-deprotonation is encouraged in the cyclic zwitterionic intermediate. Reaction was faster and cleaner than with other reagents recommended (64, 76, 77) for eliminations, such as alkoxide, diazabicycloundecene or quaternary ammonium hydroxide this new and efficient procedure may find application elsewhere. Hydrometallation or other additions to polymer-bound olefin may prove useful steps in future syntheses by polymer modification. 

One of the best known examples of polymer-transformation reactions is the quaternization of poly(4-vinyl pyridine) by various alkyl... 

Supemucleophilic polymers containing the 4-(pyrro-lidino)pyridine group were synthesized from the corresponding maleic anhydride copolymers and also by cyclopolymerization of N-4-pyridyl bis(methacryl-imide). The resulting polymers were examined for their kinetics of quaternization with benzyl chloride and hydrolysis of pj-nitrophenylacetate. In both instances, the polymer bound 4-(dialkylamino)pyridine was found to be a superior catalyst than the corresponding low molecular weight analog. 

In order to determine the efficiency of the polymers as reagents in nucleophilic catalysis, it was decided to study the rate of quaternization with benzyl chloride. Table I shows the second-order-rate constants for the benzylation reaction in ethanol. Comparison with DMAP indicates that poly(butadiene-co-pyrrolidinopyridine) is the most reactive of all the polymers examined and is even more reactive than the monomeric model. This enhanced reactivity is probably due to the enhanced hydrophobicity of the polymer chain in the vicinity of the reactive sites. 

The dielectric constant of the solvent in the microenvironment of the polymer chain has been shown to be different from that in the bulk solvent (19). This change in dielectric constant might enhance the nucleophilicity of the pyridine ring and therefore increase the rate of quaternization. The kinetic results are consistent with the observations of Overberger et al., (20), who showed that increased hydrophobic nature of the substrate led to faster reaction rates in nucleophilic catalysis. In the present case one would expect the butadiene copolymer to be more hydrophobic than the methylvinylether copolymer. An alternative synthesis of supernucleophilic polymers has been achieved using the following reaction sequence. 

Polymer properties, influence of ions, 258 Polymer surface reactions, kinetics, 322-323 Polymer transformation reactions configurational effect, 38 conformational effects, 38 hydrolysis of polyfmethyl methacrylate), 38 neighboring groups, 37-38 quaternization of poly(4-vinyl pyridine), 37-38 Polymerization, siloxanes, 239... 

Fluorene-[2,5-di(aminoethoxy)benzene] copolymers 370a,b have been synthesized by Huang and coworkers [437,438] as precursors to the first water-soluble cationic PFs 371, 372a-c (Scheme 2.58). Whereas the neutral polymers 370a,b readily dissolve in common organic solvents such as THF, chloroform, toluene, and xylene (but not in dimethyl sulfoxide (DMSO), methanol, or water) their quaternization produces material 371, which is insoluble in chloroform or THF but completely soluble in DMSO, methanol, and water. For... 

When an electron-deficient BT unit was incorporated into the backbone of these polymers, an efficient energy transfer resulted in complete fluorescence quenching from the fluorene sites already at BT concentrations as low as 1% (for both neutral and quaternized copolymers, 377 and 378) [440] (Chart 2.93). These macromolecules emit green (544-550 nm, 377) to yellow (555-580 nm, 378) light and can be processed from environment-friendly solvents such as alcohols. The PLED fabricated with these polymers showed high 4>(]over 3 and 1% for 377 and 378, respectively (A1 cathode). 

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