Quatemized poly

Significant research has been directed toward the use of polyelectrolyte complexes as blood compatible materials. Several investigators found that water-insoluble polyelectrolyte complexes can suppress blood coagulation [487-490]. Davison and coworkers reviewed and studied the biological properties of water-soluble polyelectrolyte complexes [491] between quatemized poly(vinyl imidazole) or polyvinyl pyridine) and excess sulfonated dextran or poly(methacrylic acid). By forming complexes with a stoichiometric excess of anionic charge, a more compact conformation with anionic character was obtained. 

From Table 17, one notices that the Rvalue of the particularly quatemized poly(4-vinylpyridine)(QPVP)-Cu complex is reduced and is nearly equal to the ke value of the poly(4-vinyipyridine) catalyst when a large amount of neutral salt is added to the system. It is also found by comparing the activation parameters of the electron-transfer step that the acceleration by the QPVP-Cu catalyst is due to the remarkable lowering of the activation enthalpy. 

Yancheva E, Paneva D, Maximova V et al. (2007) Polyelectrolyte complexes between (cross-linked) (V-carboxyethylchitosan and (quatemized) poly[2-(dimethylamino)ethyl methacrylate] preparation, characterization, and antibacterial properties. Biomacromolecules... 

In the polymerization of xylenol by partially quatemized poly(4-vinylpyridine)-Cu(II) complex, the binding between the positively charged polymer and the substrate, xylenol anion, is observed. The overall rate catalyzed by the polymer is five times higher than that catalyzed by the pyridine-Cu(II) complex (119-121). 

Partially quatemized poly[thio-l-(N-R1,N-R2-aminomethyl)ethylene]s are water-soluble. This allows to study their acid-base behaviour in water over the whole protonation range 69). 

Fig. 4. Potentiometric - - and viscosimetric -O- titration curves using HC1 as titrating reagent ( 3 = degree of protonation of residual tertiary amine groups 5 = overall degree of neutralization e = degree of neutralization of quaternary ammonium hydroxide sites) of partially quatemized poly[thio-l-(N,N-dimethyl-aminomethyl)ethylene]...

Fig. 6. Potentiometric titration cuves of dibiasic 17 (V-) 22 (A) 35 (O) and 48 ( ) and of partially quatemized poly[thio-l-N,N-dimethyl-aminomethyl)ethylene] (O) in water [titrating reagent, 1 M HC1)]. The numbers refer to the percent of quaternized nitrogens...

The stability constants of the Cu2+ complexes with poly(4-vinylpyridine), and with partially quatemized poly(4-vinylpyridine) have been determined by potentiometric... 

Okubo and Ise quatemized poly-4-vinylpyridine with short and long alkyl groups and conducted alkaline hydrolyas of p iitrophenyl esters 25 (w = 1,2,4,7,11 and 15) (34). The greatest catalytic effect (ca. 140 times rate increase) was observed for... 

Poly(N-alkyl ethyleneimine) was prepared directly from poly(2-alkylOXL) by reduction with LiAllit or A1H3 33). Quatemized poly(N-alkyl ethyleneimine) itself or grafted onto chloromethylated polystyrene have been used as phase transfer catalysts in aqueous-organic heterophase reactions34). 

Y. Su, X. Jian, S. Zhang, and G. Wang. Preparation and characterization of quatemized poly(phthalazinone ether sulfone ketone) NF membranes. J. Membr. ScL, 241(2) 225-233, October 2004. 

M. Li, H. Zhang, and Z.-G. Shao. Quatemized poly(phthalazinone ether sulfone ketone) membrane doped with H3PO4 for high-temperature PEMFC operation. Electrochem. Solid-State Lett., 9 A60-A63, 2006. 

Sideratou. Z. Tsiourvas, D. Paleos, C.M. Quatemized poly(propylene imine) dendrimers as novel pH-sensitive controlled-release systems. Langmuir 2000, 16. 1766-1769. 

KGM and quatemized poly(4-vinyl-iV-butyl) pyridine (QPVP) were miscible when the content of QPVP was less than 30 wt% or in excess of 70 wt%, as confirmed by SEM and XRD [51]. The thermal stability and tensile strength of the films were reduced with increasing content of QPVP, but the elongation at break was the highest at QPVP content of 30 wt%. FTIR indicated that the electrostatic interaction of QPVP and KGM impaired the partial hydrogen bond interaction of KGM. The blend films were able to decrease the lychee fruit weight loss rate and rot rate. 

Liu, C., Xiao, C. Characterization of konjac glucomannan—quatemized poly(4-vinyl-JV-butyl) pyridine blend films and their preservation effect. J. Appl. Polym. Sci. 93, 1868-1875 (2004)... 

The most frequently used anion-exchange material is protonated or quatemized poly(4-vinylpyridine) (QPVP), which has been used for the electrostatic incorporation of anionic metal complexes and for the preconcentration and detection of low levels of these metal complexes in solution. Cassidy and Tokuda reported the use of a QPVP layer to detect reversibly low levels of Cu(II)... 

Quatemized blends were also prepared as potential membranes for DMFC, such as, quatemized poly (2,6-dimethyl-1,4-phenyleneoxide)/bromomethylated... 

Fang J, Shen PK (2006) Quatemized poly(phthalazinon ether sulfone ketone) membrane for anion exchange membrane fuel cells. J Membr Sci 285 317-322... 

Xiong Y, Liu QL, Zhang QG, Zhu AM (2008) Synthesis and characfiaizatitni of cross-linked quatemized poly (vinyl alcohol)/chitosan composite anion exchange membranes for fuel cells. J Power Sources 183 447 53... 

It is useful to compare the thermotropic behavior of noncovalently complexed PLCs with their analogous all-covalent PLCs. For the case of the ionically complexed comb-like PLCs, recently published series of particularly appropriate PLCs must be mentioned, one involving quatemized poly(4-vinylpyridine) [45-47], and another quatemized poly (ethylene imine) [48-50], In both series, the quatemizing moiety is a flexible spacer (based usually on methylene, but also on ethylene oxide) CO-terminated by a mesogen. The result is a pair of ionic groups at or near the polymer backbone, just as in the ionically complexed systems described above. These systems are compared schematically in Figure 3.27. 

Polyurethane (PU) PV membranes were reported by Schauer et al. (1999). PU membranes were prepared by the reaction of toluene-2,4-diisocyanate with hydroxyl-terminated oligomers. Oligomers were either liquid polybutadiene (PB) (MW 3000) or propylene oxide-based PEs (MW 420 and 4800). The prepared membranes were used in PV of binary mixtures of water-EtOH, water-dioxane, and EtOH-toluene, respectively. Membranes obtained from the polymer quatemized poly[3-(N, N -dimethyl)aminopropylamide-co-acrylonitriles] showed selective separation of water from aqueous EtOH solution by PV (Yoshikawa et al. 1991). The separation factor toward water reached over 15,000. Membrane performance showed a good correlation to membrane polarity. DSC melting endotherms of the water-swoUen membranes were studied to clarify the state of water in the membrane. The resnlts suggested that there were two states of water in the membrane bound and free. The higher the fraction of bound water in the membrane, clearly, the more preferentially was water permeated. 

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